I have been doign some looking into and also talking to a few people around here.............from the looks of it, there seem to be 2 types of Jake brake systems.....one that is working with engine and one that is workign with exhaust system......how do you decide which is best for what you have bus wise.and one person asked me is it a problem to use a jake with an automatic transmission? Thoughts please?
If you follow my Jake thread, I now know a lot more about them than I did just an hour ago. Anyways, the only kind of Jake that works on a 2-stroke diesel like yours (ours) attaches to the heads and holds down the exhaust valves via solenoids. So, technically, it works with both the engine and the exhaust system. ;)
My coach has an automatic and the Jakes work great on any kind of incline, or even around town on the flats... when the tranny is in lockup, anyways. In your case, I seem to recall that you have a VS2-8 Allison... so, a Jake on yours will hold back your bus as long as you are in direct mode. Probably above 15mph or so. In fact, GMC built a few NewLooks with OEM Jakes and the VS2-8 (eh, Paul)... so they must work!
Living out west, and especially with an automatic coach, Jakes are a required safety item, IMHO. Coming down Vail Pass (or Cabbage or The Grapevine or...), it's like night and day. And it's the reason I'm presently covered in grease, grime, and sweat from stem to stern! ;D
HTH,
Brian B.
I have a v730 alison trnsmission.........so did you install your self? ( thanx for your post) i am trying to figure a rough for HAVING them installed as well.........
You can not use an exhaust brake on a DD 2 stroke engine it has to be a Jake brake system. I wouldn't be without a Jake brake system.
It is generally considered a major mechanical task to install Jakes. I do not recall but one or two persons on the boards over the years that have attempted it. Not that you can not possibly do it, but based on your apparent overall mechanical experience, I do not think I would recommend you try it. I know i would not and I have been working around mechanical equipment all my life.
Richard
BTW, there are several types of retarders, all work differently, including Jakes, exhaust, Thelma and transmission.
i wouldnt even consider doing it myslef :o so no worries! i am trying to get opinions on what is the best system for my bus set up and a price to expect to pay....so i knwo if im getting robbed or not ;D
Oops, V730, it is! Then we have the same tranny. Cool!
No, I wouldn't install Jakes myself. I'm just trying to fix mine... a broken solenoid or something minor (hopefully). There's a lot of mechanical work to the install... valve clearances and offsets, then a rack re-run when you're finished. Taller valve covers, wiring, etc. It's best to find an experienced 2-stoke shop... and those are getting rarer.
I seem to remember HB Industries (http://www.hbindustries.us/) out of El Cajon, CA, near S.D. carrying used Jakes. There's also an outfit in Williams, CA. You're mid-coast CA, right? Or am I getting folks mixed up again?? :P
HTH,
Brian B.
im currently in Lake Havasu City AZ but will be in Santa Cruz within a few months, maybe sooner
I suspect you are going to pay a minimum of $2,000 and possibly quite a bit more. Depending on whether you can find a set of used ones and whether you can find an old time DD 2 stroke mechanic who will moonlight and do it.
Richard
Quote from: kbunnystarr on November 07, 2006, 11:22:07 AM
i wouldnt even consider doing it myslef :o so no worries! i am trying to get opinions on what is the best system for my bus set up and a price to expect to pay....so i knwo if im getting robbed or not ;D
In response to the OP question, while Jake brakes sometimes get referred to as exhaust brakes, I think what the OP was asking is what is the difference between something like a PAC brake and a Jake. The exhaust brakes such as PAC or Banks that are typically put on pickup trucks do not alter the valve train, they are really not much more sophisticated than stuffing a potatoe in the end of the exhaust pipe. A Jake on the other hand alters the valve action such that the compression stroke pressure is relieved before it has a chance to expand in the cylinder on the downstroke. Thus the engine uses energy to compress the air in the cylinder and then uses energy to pull a vacuum in the cylinder on the downstroke. The combination of efforts creates the braking effort that Jakes provide.
Quote from: bobofthenorth on November 07, 2006, 12:16:20 PM
In response to the OP question, while Jake brakes sometimes get referred to as exhaust brakes, I think what the OP was asking is what is the difference between something like a PAC brake and a Jake. The exhaust brakes such as PAC or Banks that are typically put on pickup trucks do not alter the valve train, they are really not much more sophisticated than stuffing a potatoe in the end of the exhaust pipe. A Jake on the other hand alters the valve action such that the compression stroke pressure is relieved before it has a chance to expand in the cylinder on the downstroke. Thus the engine uses energy to compress the air in the cylinder and then uses energy to pull a vacuum in the cylinder on the downstroke. The combination of efforts creates the braking effort that Jakes provide.
To further muddle thing up, Jacobs also makes an exhaust brake.
Len
A little bit of history. Clessie Cummins, founder of Cummins engine, invented the Jake brake as we know it today. He worked with the Jacobs drill chuck company to machine and manufacture his compression brake. Cummins sold his interest in the brakes to Jacobs. Hence, the Jake brake. Later, Cummins decided to make their own brake system and called it the PacBrake. PacBrake and Jacobs both make almost identical compression type engine brakes. What is referred to as an exhaust brake is a butterfly valve that is after the turbo that stuffs up the exhaust to create back pressure, hence more braking power. You cannot use this on any of the 2 stroke Detroits since the extra back pressure would be absorbed by the roots blower and cause blower failure. Any 4 stroke engine can use either of the types of exhaust or compression brakes. Also is the driveline Telma electric retarder. It looks like a big disc brake with electromagnets on either side. It is basically an electric motor in reverse. The Telma can produce up to 800 hp of braking power. Also is the Allison hydraulic retarder. This works especially well with buses in stop and go traffic in conjunction with the service brakes. It isn't so good on a long down hill because of heating up the transmission fluid. On Caterpillars you can get the BrakeSaver which is a hydraulic retarder mounted on the end of the engine before the clutch. Same problems as the other hydraulic retarders.
If you're putting on any of them the Jake or Pac brake will work well. Every truck we sell here in Calif for over the road use has a Jake type brake installed. Have seen some mid west trucks without them. But as said before, if you stay east of interstate 25, you don't really need one. If, on the other hand, if you go west of interstate 25, go to Canada, Mexico, or Alaska, it is strongly recommended, no matter what the cost. You need only once to loose your brakes without mishap to convince you of the importance of the Jake Brake. It is those that don't survive that can't talk about it. Good Luck, TomC
thank you for all the replys! ;D
Several posts above have argued that Jake brakes are necessary to safely drive the mountains of the western US. If this were true Greyhound and all other bus companies would have so equipped their busses, they did not. Similarly if it were true the USDOT would have required them, they did not. Yes they are nice but they are not needed to SAFELY descend any mountain in a reasonably loaded bus. Slow down at the top, select the proper gear, maintain the correct (safe) speed by constant (light) brake pressure and the engine will do most of the braking even without a Jake. Yes constant light braking is the correct technique as it does produce the lowest temperature rise of the brakes. I'd like to have Jakes, but am no worse off than thousands of Greyhound drivers without them. And yes I've descended 'cabbage' , vail pass, the grapevine and many other significant western grades without overheating the brakes of my bus.
Regards
Jerry 4107 1120
Jerry -
Good point. Let's rephrase the recommendation to say that:
"Jake brakes are a very nice OPTIONAL braking device to have on your coach, which enhance the safety factor for you and your family while operating in mountainous areas. This statement also applies to other types of engine brakes, as well as hydraulic transmission and electrical driveline retarders."
;)
I like Russ' rephrase! Yes, you do make a good point, Jerry. Are you certain that modern Hound coaches don't have some sort of retarder on them (trannny, etc.)? If so, I'm surprised. Just about every heavy truck out west has 'em.
Anyways, being able to descend grades without touching the service brakes makes it much less stressful for the driver, and certainly extends the life of shoes and drums. I sure like my OPTIONAL safety device! I've done it both ways, with and without Jakes, and now won't go west of I-25 without 'em.
bb
ok so with the statements jsut made and......other types of engine brakes, as well as hydraulic transmission and electrical driveline retarders."
being said.........let me rephrase......if i want to add an additional some form of breakign system, are any of the above mentioned better or equal to the jake and is there a huge price difference. i have a big expense with this tranny, but am considering my options and would like to add something but am still a bit confused on choices.........is it just preference? or is one WAY better than the others, or..............?
Jake will be the cheapest to install. You can only install a hydraulic retarder on a V731 which is electronic. Yours is a V730 mechanical. The drive line is too short for a Telma (which is close to $11,000.00 installed). IN the case of a V drive, the jake brake is just about the only choice.
I believe, that if the bus has a Series 60 or 50, they automatically come with Jakes-including the Hounds. Good LUck, TomC
Not all Series 60 engines come with a Jake. All Dina Viaggios have the Series 60, but I have seen plenty without a Jake. Some have the Telma retarder and some have no auxiliary braking. My Dina has a Jake brake.
Brian Elfert
If you are checking around, go to dnaparts.com, in Bakersfield, and get a quote from Jerry, in service, for the jake install. You will be going right by their shop to get to Santa Cruz, if you stay on hwy 99 instead of taking I-5 at the bottom of the grapevine, or if you come hwy 58. You will never regret having the jakes and they allow longer intervals between necessary brake adjustments. Steve
Kbunny star
The last used jakes i installed on a 318 was purchased for 500 and I charged 500 to install it takes about 6 hours to install and set up. If you buy a used set make sure you get a set for 318 if that is what engine u have get the new fuel crossover tubes, new rocker covers standard high cover for right side and depending on which model bus the low profile cover for the left side and gaskets. There usually is some modifications on rocker arms that has to be done to fit jake cradle / bridge this will include setting the valves and injector timing plus jake settings and the wiring I usually insist on a one/two bank setup so if on rain/ice slick road u can use one bank if road is slick or turn off completely as they can lock up rear end and induce a slide with rear wheels locked. it's not as bad on a two stroke as per say a cummings 4 stroke engine. so I would say you can expect to spend used from 1000 to 2500 for a jake setup and yes as a bus owner/ professional mechanic for 43 years best investment you can do for a green heavy equipt driver which u became when you purchased the bus be safe and install I come down cabbage patch except for the two corners at 50 mph and only hit brakes on two mentioned corners no more white knuckle rides and stained shorts .
LarryH
If you read the other Jakes thread, I fixed my Jakes today. As an FYI for the archives, I took photos of what a Jakes setup looks like. In the top photos: the four big assemblies on top attach to the heads. You'll see two silver-ish solenoids sticking out of the bottom. Wires attach to these and when energized, push down forks that hold the exhaust valves shut. You'll also see the fuel crossover tubes.
HTH,
Brian B.
And a bit more detail...
Kristen -
Agree with Steve regarding Delaney & Ahlf in Bakersfield - excellent shop!!
Brian -
Must be using good oil. . . everything's nice & clean inside!
;)