I have a '83 MCI-9 5 speed manual with no jake break and I have a trip coming up where I will be going up and then back down a 7% grade or more..
what I am curious to know is if I get bus into 3rd gear on way down will the tranny hold it at a speed or will it try to run away and over rev the engine?
I have had smaller diesels in the past that even if i had it in a gear, engine would continue to rev to the point I would have to use the breaks to slow it down..
so if tranny will hold the speed do I need to watch other things? will engine heat up doing this etc?
thanks in advance
Slow your arse down.. with your old bus, go up in one gear, go down in one gear lower.
We would rather see you in a lively state than mourn over your cadaver in a casket.
well some of you may actually know the hill I am talking about.. it is Black Mountain in NC.
Anyone have experience as to what gear you use when pulling up the mountain? I am curious..
I have no issues going slow at all, that is why they have the slow lane on that mountain :)
I figure I will find out pretty quick when I get to it and fell the bus slowing down.. but I am a planner so the more I know before hand the better I feel.
Quote from: BRUISER on October 26, 2011, 11:55:36 AMwell some of you may actually know the hill I am talking about.. it is Black Mountain in NC. (snip)
Yeah, they call that the Old Fort grade on I-40. I can't help with bus info but I was through there a couple of weeks ago in my car. To make things worse, they are (were - maybe it's over) doing road construction on the center division and barricade so it's down to two lanes going up and coming down. My memory is that the real work is about right in the middle of the grade but of course, the closed lanes extend down the hill on the west-bound side and up the hill on the east-bound. Good luck with this one.
Do you want to BREAK it or do you want to BRAKE it.??>>>D
Yeah, that's an intense little stretch... I know it well. The runaway truck ramps are a grim reminder of what could happen!
Not to hijack the thread, but I would also wonder what the best strategy would be to climb and descend a grade like that with an automatic (Allison 740) with no jakes...
Marc
The old rule of thumb was to go down the hill in the same gear you came up it. Don't be affraid of using your brakes-just don't stab them hard-long gentle applications work best to not over heat the brakes. Good Luck, TomC
You can always gear up if you start too low but you may not be able to go the other way. The steepest grades I have run without jakes are on the 97C connector between Kelowna and Merritt. Officially they are mostly 6% grades but some of them go on for 8 or more miles and I don't know how they measure them but they are the steepest 6% grades I have run into. Its truly surprising how low you need to go before the engine provides any measurable holding. Start low.
I used to drive for Brewster's in the Canadian Rockies in the '70s. We didn't have Jakes then. Go down the hill in the same gear you go up it. Sometimes even lower. Slow with the 4 way flashers on. And like TomC says, light, steady pressure on the brakes. Jakes are nice to have, but not a necessity.
JC
Great thread! we are planning to go to that exact area next year, maybe as early as March. I never thought about planning the roads and knowing the grades, where do you get that info?
I go down steep mountains in my 33k# RTS, and do fine without Jakes. Experts say that stabbing your brakes to slow you down is better than "riding" your brakes-- I apply mine for a few seconds with force then let up wait a few seconds and do it again and it has worked for me.
Light, steady brake application puts less heat into the brake drums. If you stab the brakes hard for short times, it puts a lot more heat into the drums. And it takes hours for them to cool off.
We used to shuttle skiers up and down to Sunshine ski area near Banff before the first gondola was built in '79. One winter we had some tests done on brake drum temperatures. The least heat was achieved by light, steady application. And the recovery times to cool off were long. Much longer than the 15 mn dead head back up the hill. I remember them saying how there was still heat in the drums the next morning after sitting all night. We were taught to go down in the same gear as going up, sometimes one gear lower yet, whatever it took, no matter how slow it seemed.
JC
Someone on this board posted that you can go down lots of hills too slow but only one too fast.
That has been my watch words as I drive the mountains here in the west.
HTH
Melbo
I bring HUGGY down in 2 gear. "A v730 and 6v92 in a 04"
Just start slow and and i very seldom use the brake. I have jakes but really don't use them unless I am following a slow Truck.
uncle ned
This is an interesting topic, I was just wondering some of this same very stuff.
I was always taught to brake down well below speed, then let up to cool and try to hold your speed back with gearing. Now your all saying long and steady. Maybe over the winter I can find some Jakes somewhere, I hate burning up brakes.
Not that we have any hills over here in the Ozarks y'all would get excited over, but still.
I dont recall the stretch of 40 your talking about, but getting over the top there are some fairly long grades. My Uncles over near Franklin, and I once made a wrong turn and was headed for Maggie Valley. That is one steep road.
Curious, are there different grades of brake lining material we can run, metalic, semi metalic, different compounds etc., or is Bus brakes just Bus brakes.
Quote from: Melbo on October 26, 2011, 06:02:49 PM
Someone on this board posted that you can go down lots of hills too slow but only one too fast.
Sounds like a proverb ;) A very good one.
Pretty sure Ned is talking about your Black Mountain! thats some hill in the summertime! We have gone down it in 2nd with a 4 speed manual. When we got the jakes it was down in 3rd with manual trans and jake. Now that we have an auto and jakes, drop down to 3rd and we use the jake like the foot brake, when the speed builds hit the jakes. Some people jake all the way down. I dont know which is best but my thinking is if the jakes fail for some reason i can always air brake. By the way i always heard and was taught to hard brake on the downhill to slow but it dident seem right. Going to try the steady brake. I know this has been debated but its hard to argue with a pro drivers experience. Waiting for the Warriors opinion now!
RnM, go to www.mountaindirectory.com (http://www.mountaindirectory.com) for the info on passes and grades. They put out two books, one for the western states and one for the eastern states. Well worth having, anytime i go a new route i consult mine so i know what i can expect. And by the way guys, sometimes, depending on where you are coming from, one side of a pass may be fairly flat as you are already at altitude, and the other side going down may be really steep and long, so the old "same gear down as you came up in" doesn't work! Found that out a time or two!!!
Rant comes first:
Yup, talk is cheap, and this argument will be typed over and over.
There's more than one way to get down the mountain without burning the living #$@&^ out of the brake linings.
There are also lots of ways to set fire to your tires, the brakes get so hot, and the coach won't slow down, with you standing on the pedal, and calling on a God you have ignored for years, to come and pay attention to you...
And the "go down in the gear you went up" doesn't help a new guy who hasn't gone up the hill, and sure doesn't help a guy with a turbo and 1500 ft/lbs of torque who went up one gear down... though it is a fine old saying that describes the situation AFTER the hill has been run a few times in an older coach...
Now with that said...
The issue is that it takes a fair number of words to attempt to describe the goals, and how to reach them.
Your two goals are:
1) to keep the brakes as cool as you can, so they keep working, and
2) keep the speed of the coach under control.
Hot brakes are bad. The linings can be permanently damaged, and the brakes may not slow the coach properly, both during the intense heat, and then after the linings are burned. Many of us unwittingly purchase coaches with burned linings. Temperatures in excess of 800 degrees Farenheit are seen when this goes wrong.
(The linings are flaky and crumble in places if they have been burned. A good reason for a proper wheel end dismantle and inspection on some periodic basis.)
The coach will want to pick up speed downhill in ways that an automobile driver will never have experienced.
Since the driver usually has no way of knowing how hot the brakes are getting, "light steady brake application" has problems. What does it mean? How light? How heavy is too heavy? And who gets to pay the bills when the experiment goes wrong?
Also of particular note, light applications are notorious for only applying SOME of the brakes, not all of them, and not pressurizing/sharing properly, localized hot spots in certain wheel positions are a reality. The valving under the coach doesn't always respond as intended, especially relay valves, and a front wheel limiting valve is a killer in a 2 or 3 axle coach. And there are coaches out there with them fitted with the driver blissfully unaware...
The reason the so called "stab method" or "snub method" is advocated today, is that any newbie can easily tell how long they coast between brake applications, a newbie can tell if the coach is decelerating with some force, and a firm brake application is less likely to have the above mentioned, less than equal braking being applied.
The danger in all of this downhill talk, is that by the time you decide that you've done it wrong, it is too late, the smoke is pouring out of the wheel wells and not only will the coach not slow down, it is accelerating downhill, with your foot hard on the brake pedal.
Seek out the runaway ramp and hope the gravel is loosely packed.
So, the newbie wants a method in which he or she is able to use existing experience to make decisions.
How do you snub brake?
Reduce speed and gear down cresting the hill, as necessary. Choose a target speed, for a 6-7% grade, maybe 45 mph in 3rd gear in a 4 gear coach? You choose a speed that makes sense for the gears you have. You want high engine revs, to help keep it slow. It would not be wrong to be using 1st or 2nd gear/20 mph or even slower on the steep 12%+ back roads hills. Patience is a virtue, usually saves money and fer shure, saves lives.
Back to the 6-7% example: Apply the brakes to scrub the speed down to 40mph, and let it coast. You should be off the brakes for many times longer than you were on them. As the speed creeps back up to the target of 45 mph, apply the brakes and snub the speed back down to 40 mph, and coast again.
If you have to get right back on the brake, then you are going too fast. If with each successive brake application, the braking effect seems to be weaker, you are going too fast. (or your brake adjustment is crap, and the heat is expanding the drums out beyond the linings reach...you want to get slowed down before you can't, but then you already know your brakes are properly adjusted... I hope)
So, slow down, cut your target speed by half a gear, so maybe use 39-40 mph as the target, and drop the 5 mph to 35 or so, or drop another gear and go lower, if the coach really wants to run down the slope.
Your principle is to choose a speed that you are mostly off the brakes, and occasionally snub.
Of course, into the right lane, four-way flashers on if your speed is going to be 15-20% slower than the crowd, and if it is single lane, those behind getting impatient really do want to see you launch off the cliff on the next bend. Resist the urge to meet or exceed their expectations... Just take your time.
This might also the time to wonder about some upgrades to the rear lighting for good daylight visibility of the signals?
happy coaching!
buswarrior
Ed, as a new hired driver, we were trained on every piece of road there was around Banff, L. Louise, Jasper, Calgary and Edmonton (city tours, airport runs, etc). It took 3 weeks. So we pretty well knew what gear to use where. After a few months with more seniority, and more experience, we got turned loose on long distance charters. By then, we had more of a feel for a bus. Brewsters still trains this way. Not many companies do that anymore.
JC
As an addendum to BW's excellent comments, I'd like to add the following:
Pay attention to the yellow caution signs put up by the highway dept for the truckers, if done so in the area you're traveling.
Staying within the guidelines of the signs gives you happy memories of the trip.
Oh, and add some $$ to the budget for Jakes, well worth the investment.
FWIW & HTH. . .
;)
Quote from: RJ on October 26, 2011, 08:57:30 PM
Oh, and add some $$ to the budget for Jakes, well worth the investment.
RJ,
We have seriously considered getting a jake brake. Do you have any idea what it would cost to have Jake's put on my 4106?
Quote from: Ed Hackenbruch on October 26, 2011, 07:41:08 PM
RnM, go to www.mountaindirectory.com (http://www.mountaindirectory.com) for the info on passes and grades. They put out two books, one for the western states and one for the eastern states. Well worth having, anytime i go a new route i consult mine so i know what i can expect. And by the way guys, sometimes, depending on where you are coming from, one side of a pass may be fairly flat as you are already at altitude, and the other side going down may be really steep and long, so the old "same gear down as you came up in" doesn't work! Found that out a time or two!!!
Thanks Ed! I will have to get the books. Priceless info :)
Quote from: DMoedave on October 26, 2011, 07:09:11 PMPretty sure Ned is talking about your Black Mountain! thats some hill in the summertime! (snip)
Yes, it's I-40 going downhill from about Exit 67 to Exit 72 (about 15 miles east of Asheville), exit 72 is to "Old Fort, NC". It's kind of hard to go around - if you're heading from/to Asheville from/to Charlotte, you could take I-26 and "come in from the south" but that grade (between Tryon and Hendersonville, called the "Saluda Grade") is about as bad. If memory serves, it's a little longer but not quite so steep. I think that they're about the two worst grades in the southeastern US (but if there are any worse or as bad, I'd like to know about them).
Hi I know this mountain very well. big truck are limited to 35 mph.If you stick to that you will have no problems. gear down only break lightly to keep speed down under 35, stay calm and you will be fine. If you are going thru I-40 toward Knoxville same deal . good luck. papatony
Thats really the key no matter what your driving, to use a low enough gear you dont need to brake, or only brake minimally to check your speed. If you have to stay on the brakes to maintain speed, your going to fast.
I grew up in Duluth, learned to drive there and took my driving test there. My Dad taught me never to ride my brakes. He drove back and forth from Minneapolis to San Franscisco between '43 and '53, more times than him and Mom could count, more than 25 trips that he was aware, and more than once on US 40 out of Denver through the rabbit ears. They saw trucks and buses and cars 1000 feet down over the sides of mountain grades, back then they didnt run right out and haul it out, pick up bodies, they didnt have the manpower or equipment. Most of it was burned, FUBAR.
Back in Duluth, I cant count the Trucks that lost brakes coming down Thompson Hill on Cody Street and wrecked. Always same answer, its Minnesota, they didnt think Minnesota had any grades. Once they ran out of brakes and couldnt drop a gear they had a runaway truck. And there wernt any run offs, so they plowed through cars or houses or whatever was in their path. Putting 35 through into downtown sure stopped all that craziness.
I was in 7th grade. One afternoon the whole building shook, we all thought it was an earthquake, stuff rattlin and books falling off shelves. A grain truck had lost his brakes coming down Cody. Having grown up in West Duluth, he knew (he lived, surprisingly, took 3 hours to cut him out) this one house was vacant. A big two story on a the NE corner. Built in the late 1800's out of big rough sawn oak, big oak timbers underneath (we used to sneak around in it). He rolled over the oncoming lane, up over the curb, and took the porches off every house for a block before crossing the street and aiming the rig into the corner of that house. Shoved the entire house 8 feet off the foundation.
The worst one was a guy in a dump truck came down 24th street, couldnt stop, took out three or four giant oaks along the side of the street, jumped the curb, ran through a school gymnasium, then down into a creek. No one was ever really sure at which point he was dead.
Use low gear, whatever gear holds you back without braking a bunch. Stay off the brakes. Im stickin with snubbing it.
all great info.. thank you all for what you have posted..
I see and understand always best to be in a low gear and I can decide if i want to shift into a higher gear but going back down into a lower gear will be very hard..
my original plan even before posting was to get into 2nd gear and just take my time going down and see how the bus reacts to this..
I guess the one thing I did not see answered unless I missed it.. is if I am in 2nd gear will the tranny only let the bus go so fast.. or will I still need to use the brakes a few times to slow it down, and if I was t onot use the brakes but let the tranny do all the work am I causing long term issues with tranny by doing this?
oh and one last question where is the best place to get jakes for a 8v71 in a MCI bus?
thanks again
It's not the tranny you need to worry about, it's over speeding the engine. Don't let it get any faster than the max speed you could make in a particular gear.
Quote from: Len Silva on October 27, 2011, 06:49:11 AM
It's not the tranny you need to worry about, it's over speeding the engine. Don't let it get any faster than the max speed you could make in a particular gear.
thanks that is what I wanted to hear
If you are in a low enough gear, it will slow you down enough that you will have to press the accelerator to not slow down too much. You might decide to upshift if you think there is nothing steeper yet ahead of you.
If you are in a gear that doesn't quite hold the vehicle back, you will gain more and more speed, necessitating the use of the brakes and/or Jakes to control it. You have to keep the engine revs at or below the max speed (usually 2100, 2200 rpm) so you don't damage the engine. The trans won't care about overspeed, it is the engine that will take the damage.
Of course, to be able to down shift, you have to be at around (depending on your bus) 1500 rpm, so that the lower gear will be able to engage and not over rev the engine.
JC
Len Silva beat me to it and explained it more clearly.
Something else to keep in mind is that not all grades are the same. What do i mean by this? You can have a 6-7% grade that is straight or has 50 mph curves that goes for miles that you can cruise down in 3rd gear and never have to touch the brakes. You can have a 3-5% grade that has 15-20 mph curves and is only a mile or two long and go down it in first or second gear and be on your brakes for the whole way. The directory i mentioned will tell you about the curves and mph and i learned real quick to pay close attention to that, it tells me more about the road than just what the percentage of grade does. ;D
I've been down that I-40 hill in my pickup towing my race trailer, and it is a doozy. I passed a mobile home trailer, on eof the ones with a dozen sets of wheels under it, and the smoke coming out was interesting to say the least - it was doing about 15 mph. In my bus with no jakes I'd be in second gear, up or down. In my truck I was in third gear.
I was trained to use BW's methodology, and do use it. My trip through Quebec and New Brunswick from Rivier Du Loop has many grades up to 9% or so, long ones, and I never had a problem with third gear or fourth gear and snub braking. I find that if a road is designed for 70 mph, I can roll down it at 70 not overspeeding in fourth and snub braking as required with no (in my case, simply mis-adjusted and not working) jake brakes. It's the roads that are designed for 50 mph that are interesting and challenging.
Brian
Observation: on Andy's Toter home was told previous owner overspeed engine going down grade in west and twisted shaft off in injector pump. Cummins powered. FWIW.
Never had to deal with steep grades of the west: So I have been reading and learning. Thanks for that. It makes sense to me. I will be the slow poke going down the steep grades. I understand the Jake principles but other than knowing my bus has them --that is where it ends. Learning something new every day. I'm retired and in no hurry! Bob
Quote from: robertglines1 on October 27, 2011, 09:10:31 AM
Never had to deal with steep grades of the west: So I have been reading and learning. Thanks for that. It makes sense to me. I will be the slow poke going down the steep grades. I understand the Jake principles but other than knowing my bus has them --that is where it ends. Learning something new every day. I'm retired and in no hurry! Bob
heck, I am young and in no hurry :)
Quote from: BRUISER on October 27, 2011, 06:38:30 AM
I guess the one thing I did not see answered unless I missed it.. is if I am in 2nd gear will the tranny only let the bus go so fast.. or will I still need to use the brakes a few times to slow it down, and if I was t onot use the brakes but let the tranny do all the work am I causing long term issues with tranny by doing this?
If the gear your in is too high for the grade your decending, the engine cannot hold it back and youll pick up speed where youll have to use brake. The engine governor only keeps the engine from over revving while under power, there is nothing on Gods green earth to stop it from over revving if its being driven by the transmission through momentum. If your in any gear, and you get it above the next lower gears redline speed, and you cant slow it down because the brakes are gone, you can no longer downshift to the lower gear because you cant rev the engine high enough to get it in. And Auto's wont down shift to a lower gear once their going a certain speed either. Personally, if it was running away in second or third and I couldnt slow it down with the brakes, id keep it in that gear and let it unravel and pray it didnt blow. And once it nears governor redline speed, if you put in the clutch and shift out of gear, youll never get it back into that gear either. And if the gear you were in wasnt holding it back, the next ones going to be like neutral and your going to be in real trouble. At least if the engine explodes it will lock up (hopefully), and youll have one last chance of stopping it.
If it comes out of gear and your brakes are gone, they better look out below, or you better pray you find one of those run away truck ramps. Man those look scarey. I would hate to ever be in a position where I was hoping to find one. Best to just get into that lower gear before you go over the hump.
"I looked at Earl and his eyes was wide, his lip was curled, and his leg was fried. And his hand was froze to the wheel like a tongue to a sled in the middle of a blizzard. I says, "Earl, I'm not the type to complain; but the time has come for me to explain that if you don't apply some brake real soon, they're gonna have to pick us up with a stick and a spoon."
I think thats what Dad used to say, "brakes are for stopping, not for holding speed on a grade".
I have an auto with 2-stage Jakes, and they certainly make life easier. However, we did go down the same grades before with the Jakeless Spicer. You just go slow in a low gear. If you are in third and starting to pickup speed faster than you should, don't wait until the gear tops off. Brake and bring it down to second. You could just start one gear lower than you think will be right. If the bus maintains speed, or almost does, without braking, your in the right place. If the bus is slowing down, you can consider the next gear. Knowing what is in front of you also makes a difference. If you see that you have a clear, straight run at the end of the grade with no traffic in the way, you can consider up shifting and picking up some speed. If there are curves, just crawl along.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.mesalek.com%2Fcolo%2Fpicts%2Fus160wolfcrtruckspeeds.jpg&hash=0f3df3b6ec2802012eb8a4a40500a3cde7617fc8)
Oh yeah, as you crawl along at 15-20 mph, you might feel like you have time to get up and make a sandwich, but don't do it.
About 22 years ago when I got my CDL, the one question I missed, I will never forget. The test said that going down a long 6% grade you should apply light even brake application. I got that question wrong. (My answer was to snub the brakes) All these years of driving, I have been using this method. So after this thread started I did some research, this research conformed "BW's theory" here is the article.
Downhill Braking
Snub don't ride!
•Some drivers don't understand the severe demands put on the brakes by long downhill runs. Suppose your doing 6 miles with an average 6% downgrade. Runs like this are common out west. (In the east too?) This is a 1900' change in elevation. A free fall from 1900' results in a terminal velocity of 238 mph- neglecting air resistance. This would be the velocity of your rig -neglecting air and rolling resistance- if you didn't brake.
•Negotiating this grade is the same as slowing down from 238 mph. This is like 16 stops from 60 mph (not 4, kinetic energy varies with the square of the speed: (238 x 238) / (60 x 60) = 15.74 ) Suppose you average 30 mph coming down, the run will then last for 12 minutes. Sixteen stops from 60 mph in 12 minutes is a lot of stopping. Obviously your brakes had better be right and you had better use the right braking technique if you want to make it safely to the bottom.
•In recent years there has been some erroneous information going around about how to brake on long downhills. It was suggested not too long ago that a continuous application of the brakes as opposed to intermittent application or snubbing was the preferred method. THIS IDEA IS COMPLETELY WRONG!
•The proponents of the old theory have rescinded it, there is now (almost) universal agreement that the proper way to brake on a downgrade is to intermittently apply all your service brakes in a way that will reduce the speed of a fully loaded vehicle by about 5 or 6 mph during each application. What is key here is not the speed drop, this will depend on weight, grade and other factors, but air pressure, you have got to get the application pressure high enough to get all your brakes working.
•In theory, it doesn't make any difference whether you ride or snub the brakes on the way down. The problem is that you don't drive a theory, you drive a truck. In theory, the same amount of heat is put into the braking system regardless of how you apply the brakes. In practice, unless your brakes are in good condition, tractor-trailer balance is right and the load is ideally located, the continuous application of the brakes is likely to result in uneven drum and lining temperatures and problems before you get to the bottom of the hill.
•Steady, low pressure application of the brakes may not cause all the brakes on the vehicle to apply and may result in some brakes -those with the lower activation pressures- doing more work than others. Specifically, in many cases the tractor brakes will do too much of the work while the trailer brakes loaf and you might then get fade at the tractor axles.. Other brake problems can be aggravated by the low and steady braking technique. What you want is all the brakes working some of the time, not some of the brakes working all the time. The application pressure must be high enough to ensure that all brake chambers apply and that all linings make solid contact with the drums - about 20 psi or higher.
I may get pounded for this statement? But I think all of us bus owner's that don't have CDL's should at the least have an air brake endorsement!
Do you think the same theories would apply to:
1. Disk Brakes?
2. Anti-lock brakes?
Len ; good ? I have them on 98. Bob
Quote from: Len Silva on October 27, 2011, 02:19:03 PM
Do you think the same theories would apply to:
1. Disk Brakes?
2. Anti-lock brakes?
As far as my researches go, yes I do.
Here is the the proper tecnique according to the Commercial drivers manual here in Alaska.
5.4.6 – Proper Braking Technique
Remember. The use of brakes on a long and/or steep downgrade is only a supplement to the braking effect of the engine. Once the vehicle is in the proper low gear, the following is the proper braking technique:
• Apply the brakes just hard enough to feel a definite slowdown.
• When your speed has been reduced to approximately five mph below your "safe" speed, release the brakes. (This application should last for about three seconds.)
• When your speed has increased to your "safe" speed, repeat steps 1 and 2.
For example, if your "safe" speed is 40 mph, you would not apply the brakes until your speed reaches 40 mph. You now apply the brakes hard enough to gradually reduce your speed to 35 mph and then release the brakes. Repeat this as often as necessary until you have reached the end of the downgrade.
Quote from: Len Silva on October 27, 2011, 02:19:03 PM
Do you think the same theories would apply to:
1. Disk Brakes?
2. Anti-lock brakes?
Len -Yes and yes.
However. . .
Disc brakes can tolerate far more heat than drum brakes, simply because so much of the disc is exposed to cooling air. I've often seen discs that were "cherry red" from heat on race cars that were still functioning. But if the PADS are of the wrong material, the discs can fade just as badly as drum brakes, altho it will be further down the mountain when it happens. The pad material used on HD equipment like our buses and trucks is designed for high temperature operation, so it will take a LOT to get 'em really hot enough to fade. But you can still do it by using stupidity.
Anti-lock brakes are affected by heat just the same. They're designed to release the brake to allow the wheel to start rolling again when it starts to
slide (the old "pump the brake" idea, but so much faster than a person is physically capable of.) If/when the discs/drums/shoes/pads get hot enough for fade to set in, the wheel will keep right on rolling, not sliding like on ice. At this point, anti-locks are useless - look for the runaway truck ramp.
One big difference between the grades in/around the Appalachians and those in/around the Rockies and Sierras are the
lengths of the grades. A couple of examples:
I-5 NB from Los Angeles over the Grapevine. Summit is 4144 feet - once you crest it and start down, you've got about three miles of 4%, then it changes to a little over six miles of 6%. Trucks are restricted to 35 mph, and there are at least three runaway truck ramps - often used.
I-80 WB from Reno, NV to Sacratomato, CA. When you crest Donner Summit (7229 feet), you'll now be faced with 70
miles (yes, you read that correctly,
miles) of 4, 5 and 6% grades until just east of Rocklin. Brake killer. But CalTrans has intelligently (is that an oxymoron?) posted yellow warning signs for the trucking industry advising safe speeds for decent. There are some runaway ramps, but they are not utilized nearly as much as those on the Grapevine.
Back when I was in the charter bus industry, the majority of the fleet had jakes, with the exception of the two 4106s and two of the older Buffaloes (the newer 4905s had them). All the MCIs, Eagles and Prevosts had automataics with jakes. After I became familiar with the road, it was easy to hold a steady 65 mph in 4th with the Jake coaches all the way down, never having to touch the service brakes, except for traffic. (Nice to have cool brakes!!) The non-Jake coaches were kept in 3rd with little to light braking as needed (more braking was needed with the 40-footers).
Let me put it this way: Going downhill means you have to DRIVE the coach!
FWIW & HTH. . .
:)
Never having driven a bus before, I bought my Gillig Cummins/Allison with 3-stage Jakes in Arizona. I stayed overnight in Golden Valley (between Kingman and Bullhead), and used the high-idle switch to aid in airing and warming up in the morning. While descending the long, steep grade into Bullhead & Laughlin (93?) I knowingly and confidently threw the Jakes switch, with no effect whatsoever! I was only going about 45mph, but it did spike my adrenalin. About the same time a few gentle applications of the brakes convinced me it could be stopped, I realized the high idle switch was left on, thereby defeating the Jakes. The rest of the descent consisted of a pleasant, reassuring rumble :).
I have been over many passes at close to 80,000 lbs usually without any jake brake. If you use your head everything will be fine. Read the signs and keep your speed accordingly. Those speed limits were set for a reason. I have always used the snub method and only had problems once. I crested the hill and did not downshift. Half way down I was somewhere north of 80 mph and had no brakes from trying to ride them and then snub them after they started to get hot. I made it to the bottom in one piece but had to change my underwear at the bottom. Talk about maximum pucker factor. Needless to say, I never made that stupid mistake again.
Anti-lock brakes will NOT prevent you from overheating brakes. They only prevent a wheel lockup in a skid. In this day and age, everyone should have a Jake brake. Especially if you're coming west through the Rockies. I know that most of the big trucks have Jake brakes as standard equipment. Even Cummins ISC 8.3 and ISL 8.9 liter have the option of Jake Brakes. Cummins little ISB 6.7 liter has a turbo brake-meaning the turbo vanes switch to rev up the turbo and cram more air into the cylinders for a mild Jake brake effect-it is very affective on less then 26,000gvw trucks. Good Luck, TomC
Yes, Jake brakes are great to have, but they don't help one bit on any of the medium steep hills out west where they are prohibited by law. I will admit I broke the law and used my Jake brake anyhow. I do have a muffler and I like to have my service brakes cool in case I need them. There was one grade last month were I was almost going too slow, but you really can't go too slow downhill.
Here in the Ozarks we do have several 7% to 8% grades, every day I drive a 2 lane state highway where the grade is not marked but you drop a little over 1200 feet vertical in about 2 miles.
I was on a local Fire Department Rescue team that worked a passenger bus wreck on the mountain south of Jasper Arkansas in 1980 that killed more than 20 people, the bus lost brakes about 2/3rds of the way down the mountain at the time no run-away hill ramp.
My approach to descending a grade with a manual transmission is very different than my approach to descending with an automatic transmission with no Jake.
I can descend the mountain with my 4104 with the 4 speed Splicer in 1st gear flashers going and only touch my brakes about 4 times on the way down. I always keep my hand on the shift lever to prevent the transmission from jumping out of gear. It never has but it could be bad news to have a Splicer in neutral while rolling down a grade. I have owned trucks with Allisons and it is my experience with them that trying to go too slow by downshifting into TOO LOW a gear and trying to maintain too low a speed on the first few miles of a grade can actually lead to more brake fade on the lower part of the grades than dropping just 1 or 2 gears (with an automatic) and descending at a slightly higher speed and not braking as much. I always try to "save" my brakes as much as I can on the first 50% or so of the grade so I will have cooler brakes on the lower end of the grade.
Years ago (I was 17) I had a 1947 1 1/2 ton Ford truck with mechanical brakes (you push the pedal and a rod connected to a wedge applys brake pressure to the drums) and hauled hardwood logs down this grade, that was fun at the time but I would not do it today for any amount of money.
This can be where a CB radio and talking to truckers about a grade before you get to it can be a big help. If you have a bus with no Jake and an automatic the advice the truckers give you might not be what you want to do as they probably have a manual transmission. Just my 2 cents worth........
Rick
Quote from: belfert on November 03, 2011, 10:55:40 AM
Yes, Jake brakes are great to have, but they don't help one bit on any of the medium steep hills out west where they are prohibited by law.
Brian -Where did you see that Jakes are prohibited?
???
On I-80 coming westbound into Salt Lake City there is a long grade and engine brakes are prohibited. Interstates typically don't have grades nearly as steep as other roads, but I have smelled plenty of burning brakes coming from other vehicles on this grade. I'm thinking there is at least one other stretch where engine brakes are prohibited.
The last I read there was 10 states that prohibit engine brakes in a Village or City limits,NM,OK,OR,PA,UT,WV,WV,KS,CA and 1 other I forgot
good luck
Coaches with proper mufflers are not going to attract anyone's attention with the engine brake purring.
Trucks with straight pipes, on the other hand...
In these areas, get the transmission down into the right gear to help blend the package, so you may be using transmission and partial engine brake, if the slope allows.
Engine brake off before you hit the bottom of the exit ramp, the city cops will hang at the end of the ramp and nail the ones jaking all the way down to a stop.
Our brakes do need some sort of regular workout too for good lining/drum health.
happy coaching!
buswarrior
Usually, but not always, what you see is the signs say no unmuffled jakes, meaning no jakes running thru straight pipes. If you have mufflers on your exhaust you can still use your jakes. :)
I've personally never seen a sign that says unmuffled engine brakes restricted. I'm sure they exist, but I just haven't seen one. Every one I have seen says engine brakes or Jake brakes prohibited. (Jake brakes is rare because the company lawyer will contact the owner of the sign to take off Jake Brake.)
I have attached a photo of the sign on I80 in Utah prohibiting engine brakes.
It's all about the noise as I'm sure you have heard in trucks. If you have a muffler, there will not be the characteristic clatter, so I would not worry about it.
Brian, why worry about the ticket? I have never heard of a bus owner getting a ticket for running his jakes.
Coming down the pass not using jakes vs using the jakes, I would risk the ticket every time. If you have a muffler and with most designs the outlet of the muffler is pointed to the ground. The noise is greatly reduced vs truckers with open stacks.
I always run my Jake brake on that grade regardless of the sign. I do have a working muffler. I've never been worried about a ticket.
I personally I have never heard (ever) of a person being cited for running jakes and being found guilty in court - If you've paid a ticket and not fought it shame on you - factory installed jakes are a "safety device" no different than rear view mirrors, and are NEVER to be considered a nuisance - Yes I have traveled thoroughly throughout NA and have seen all the signs both muffled and outright bans - I usually turn my jakes on to see if anyone will pull me over - never been stopped and would easily win in court - There is a fair amount of case law out there that supports my opinion and if any of you ever find yourself defending the use of your jakes please contact me and I will help you as best I can - leave it up to the government to outlaw safety devices and then fine you for not using your jakes - FWIW
I would probably just pay a ticket if I got one as traveling from Minnesota to Utah for a court date would be very expensive.
When it comes to hills and jakes, often I choose safety.
Dropping into SLC, we will run the jakes. That said, we are quieter running jakes, then some trucks with straight pipes.
Quote from: belfert on November 05, 2011, 06:34:21 AM
I would probably just pay a ticket if I got one as traveling from Minnesota to Utah for a court date would be very expensive.
You have to watch the "just pay the ticket" stuff. In NC, if you have an excessive speeding ticket (most of us would never have that issue) then you HAVE to appear in court, no matter where you are from. We have a friend who is a trooper in NC, and he says people just figure they can pay the ticket and be done (again, high speed, not just a regular ticket). If the folks don't show up in court, they are barred from driving on any state/city roads. Of course, that is different then a minor jakes/no jakes, but still a thought.
John
I don't know who commissioned this report but it does answer some of the questions on a few states - with statute numbers for reference.
http://www.cga.ct.gov/2004/rpt/2004-R-0741.htm (http://www.cga.ct.gov/2004/rpt/2004-R-0741.htm)
What really bugs me is towns that put a stop sign/red light at the bottom of a steep entrance into town and then put up "No Jake" signs. I ignore those signs completely and in fact probably go out of my way to use my Jakes in those situations. If I should happen to ever get cited for that use I'll definitely make the court appearance because I'd really like to meet the judge who is stupid enough to let that ticket stand.
Quote from: belfert on November 04, 2011, 10:14:36 AMI have attached a photo of the sign on I80 in Utah prohibiting engine brakes.
That sign says "restricted". That's not exactly the same as "prohibited". A good lawyer could have some fun with that.
Essentially what's being sanctioned (now there's another ambiguous term) is unmuffled exhausts, not Jake brakes per se. Like so many vehicle requirements, enforcement is capricious and inconsistent, and more focused on generating quick revenue than promoting safety.
John
You can tell when an unmuffled truck is running Jakes. I doubt anyone could say the same about a muffled bus.
Quote from: Iceni John on November 05, 2011, 03:00:37 PM
Quote from: belfert on November 04, 2011, 10:14:36 AMI have attached a photo of the sign on I80 in Utah prohibiting engine brakes.
That sign says "restricted". That's not exactly the same as "prohibited". A good lawyer could have some fun with that.
Without a definition of what "restricted" means I take it as a prohibition against the use of engine brakes. If they only want to restrict unmuffled engine brakes they should say so.
just wanted to post an update..
ended up taking a different route due to others going with us and went up Fancy Gap instead of Black Mountain.. Bus pulled fancy gap in 3rd gear with no issues at all. and went back down on way home in 3rd also..
trip was great minus the blown tag axle tire on way out.. but was still great.. but I am now looking for jakes breaks as I could see the difference my buddy had with them going home down the mountain..
Quote from: BRUISER on November 07, 2011, 11:43:28 AMended up taking a different route due to others going with (snip)
Good, I came down the I-40 hill last Weds. The construction barriers are still up. If there's any traffic at all, it gets very tense. You prolly did the right thing.
Back when I was trucking I got ticketed more than once for the "no jake brakes" signs!
Salt Lake was the first one. I did as usual I contacted a lawyer and told him what I had gotten the ticket for and why I wanted to fight it.
It wasn't to keep it off my record, or to save $ but more of the principal of the fact that I was ticketed for using a safety device.
He took my information and said he'd call me back. Later that day he asked me if there was anyway I could come through Salt Lake and meet up with him anytime soon.
I told him I most likely could on my way back depending on what kind of load I got and where it was going to.
Well the next day I unloaded in Seattle and reloaded back to FL and called him and told him I'm meet him on my way down.
We decided to meet @ the Sap Bros Truck on California Ave off I-15.
I spent the night there and in the morning he arrived @ the time we agreed upon and went inside to "meet" over breakfast. First off he was amazed that they had a "smokers club" dining room for CDL drivers only.
Then we talked over b-fast and discussed the exact details of the citation, trucks in general, fake brakes & how they worked, and other exhaust brake systems.
After b-fast he asked me to ride out to the site where I was ticketed with him.
We talked more as we drove and every once in a while I'd hear a truck using the jake brake and would tell him that is what he was hearing.
When we got to where the sign is he hummed something and laughed while taking notes. All the while trucks going by and turning on the jakes as they went by.
As we started down the hill he pointed out that on the other side of the wall was the most exclusive country club in the Salt Lake area.
He said he'd check farther into it for me and took me back to my truck which he immediately fell in love with the 10" straight stacks, the 8" Stainless drop sun-visor (dropped 8" down over the stock one), and all the other stainless, chrome & chicken lights my truck had.
When he called me back he said he was going to fight my ticket for me on a $500 retainer, but he was going to find other drivers to join in on the fight and if he did I would get all my $ back and we'd file a class action suit against the city. (he despised the country club & most of it's members)
He fought the tickets and won. Well actually the judge threw them out the minute he presented proof that jake brakes are indeed a safety device that assists and saves the service brakes. The class action suit was denied because all of our tickets had been dismissed.
But I got several other tickets in different states and he took care of all of them for me @ no charge and told me I'd put him on to a $ market of fighting them and he made $75-100 off from every one he fought and all he had to do was call the local prosecutor where ever the ticket was and as soon as he explained to them who he was, why he was calling and that he was willing to find enough drivers to make it a class action suit they dropped the ticket.
SO yes they will ticket drivers for using them. But they are mostly aimed at guys like me that have had straight stacks and deliberately used to rattle all the windows in town and set off alarms in cars and buildings all along the main street.
;D BK ;D
Thanks for the story BK. It's good to have a happy ending once in a while with things like this.
Quote from: Lin on November 07, 2011, 04:20:20 PM
Thanks for the story BK. It's good to have a happy ending once in a while with things like this.
I don't know if he ever got his class action suit he wanted or not.
He wanted one bad and told me so, said he could retire of the fees if he ever got & won one.
I gave up trucking 11 yrs ago.
;D BK ;D
I'm a bit confused on how this lawyer was going to hit it big on a class action suit regarding traffic tickets. Was he planning to charge each defendant a few hundred dollars? Most class action suits are against companies for monetary damages with the lawyers getting a chunk of the settlement. There are no monetary damages to be had here.
bw, thanks for confirming the method i use on my brakes when needed. We bought jakes a few years ago. ended up costing about $3000 installed, but well worth the money as we full time. when i left colorado, we had to go over a 12000 foot pass, from 8500 up, then down into denver. pulling the van which is about 7000 lbs with the bus (about 39000). i barely touched the brakes and we went up at 20mph, then down at 20mph. 1st and 2nd. We have a 740 automatic.
Personally-no such thing as a too quiet truck. Now with the Detroit DD engines having a separate camshaft (dual overhead cams) to power the Jakes, they are both powerful and very quiet in operation. And with all the smog devices on the exhaust that you can't touch by law-no such thing as straight pipes anymore. Good Luck, TomC
Brian,
As I said I don't know his plans or methods to his madness. Just that he said if he could ever get and win one he could retire from it.
TomC If you remember correctly I was a chicken hauler! (and a damn good one at that!)
I gave up trucking in 1999/2000 and haven't looked back since!
I did get pulled into the Winterhaven, CA weigh station early one AM (like 3 AM) when 3 of my trucks were running together.
I told my drivers on the CB to go ahead and go up to the rest area in the center a ways up the road and I'd be there soon.
The officer had his CB on and responded "yeah he won't be long just a quick level 2 inspection and he'll be on his way!"
So I went around back and parked and by the time I opened the door there he was. He asked for my paper work, glanced @ the log book and handed it back to me. Saying "won't be needing this for what we're doing." And stuck my license, registration and BOL's under the clip on his clip board and said "I will need info of these for the citation."
So then I sat in the truck while he walked around the truck checking lights, tires and brake stroke. Then he came back up front and asked me to open the hood.
He said "I see ALL your lights work, you have great tires & brakes and it looks good under here. I just need to get a ladder and look down those huge exhaust pipes and make sure there is a muffler down in there!" (10" straight stacks remember?)
I told him "Of course there is that's why they are huge to hide the muffler and look like straight stacks."
He said "I still gotta look. by the way this sure is a pretty truck and it shows you keep up on maintenance."
About that time he showed back up with a 6' step ladder and a pole with a mirror on it! He stood about 1/2 way up on the ladder stuck his pole up near the top of the stack and shined a light on the mirror and said "Yup sure is a muffler in there! That's a pretty clever way to hide it!"
I said "yup, what's next?" He said "nothing I just gotta fill out a report showing you passed an inspection" which he did and I left laughing all the way!
;D BK ;D
So if the other trucks were heading west on I-8 there, the rest stop they pulled over at was at the Algodones Sand Dunes. I hope you got a look at it in the light. The area is quite spectacular and has been used as a movie set. "Stargate" comes to mind. I once was driving past there and got caught in a massive sand storm. There was zero visibility. The only thing anyone could do was pull over and wait for it to pass while hoping no idiot was going to slam you from behind. Of course, if you were heading east, ignore what I said.
Yes Lin we were headed west to Chula Vista, CA hauling fresh iced down chicken to a warehouse that would make us wait until after the Federalies opened the boarder and allowed the mexican trucks to come across and pick up the loads.
We'd run that run many times and yes I have seen the beauty and the ugly of it both!
;D BK ;D
We have an '88 Model 15 Eagle with a 740 Allison, 6V92 and no jakes. It was formerly a 'hound, so it's geared pretty tall--it doesn't hit 4th gear until about 55 mph. The gearing is a bit important if you're trying to decide what gear (and subsequently speed) to head down the hill.
Typically, on an unfamiliar 6-8% grade, I'll hold it in 2nd gear, which will give me about 40 mph at max rpm. I'll usually start the hill about 30, let it gradually roll up to about 40, then brake until I'm down around 30 again.
My preferred method of brake application is to apply about 5 lbs of application pressure for about 5 seconds; that'll cover the slow down between 40 to 30 mph. If you have an application gauge, get a feel for a low application pressure. . .the brakes stay a bunch cooler at 5 lbs of pressure than they do at 15-20 pounds.
That's my humble opinion. . .drive safe!
I have driven Old Fort Hill in a standard transmission and a automatic / without jake. In the standard transmission you climb in 2nd and down hill in second. Also 2nd in the automatic down the hill..When the rpm go higher than you want you use a little brake to lower engine rpm. This hill is steep but with care can be traveled with care.