I have auto slack adjusters and it appears the front ones are probably bad. I don't want to keep replacing these things at $134 each. If the bus sits a lot would I be better off with manual ones? Would it even be legal to switch to manual slack adjusters since mine is a 1995 and I think this is after auto slack adjusters were mandated on air braked vehicles.
Everything is in adjustment now, but my understanding is if you have to manually adjust auto slacks they should be replaced.
Depending on the s cam shaft splines you may not have a choice with the adjusters
good luck
I just replaced my front ones with manuals. I like them better. The slack is only 3/4", compared to 1 3/4" with the autos.
I heard you're supposed to adjust the manuals once in a while, LOL.
JC
Brian Clifford is correct.
If they didn't have an option of both available you probably won't find any to fit your S cams shaft.
You could have the S cam shaft replaced to ones that manual slack adjusters would fit on. But that is a lot of expense !
I'd make sure that the ones you have are properly installed and have the bracket that makes them adjust positioned correctly! (biggest problem I've found w/autos is people don't have this done!)
If they are indeed bad I'd grease adjust them before your trip out west. Then once you get there check and see if they are out of adjustment again. (a Dina is easy since they sit up good and don't have bags to go down on you. Plus of you turn the wheel you can reach it without getting under it.!)
If they are pretty much the same or close to what they were before the trip I'd just keep 'em and adjust them before each trip! (ain't like you drive it a lot!)
;D BK ;D
Back up the bus...
Brian, what makes you think they are bad?
JC, what was the adjustment limit for that brake, and were the autos set-up properly?
There is so much time and money WA$TED changing automatic slack adjusters that are fine, and too many people claiming to know what they are doing with them who DO NOT.
An automatic slack adjuster can best be thought of as a ratcheting device. When the lever moves past the ratcheting point, it advances the mechanism so the lever doesn't have to travel as far the next time. This compensates for brake lining wear.
The trick is knowing how to set this point of adjustment correctly, and that can be VERY different between manufacturers as well as between a given manufacturer's models.
This is yet another time when parts identification and proper procedures, as detailed in the manufacturers written directions, should be followed.
But there's more money in selling new parts...
happy coaching!
buswarrior
Quote from: buswarrior on August 31, 2011, 09:01:41 AM
Back up the bus...
Brian, what makes you think they are bad?
Something happened to the front brakes and the brakes were not braking evenly. The shop looked at them and adjusted them, and said I just need to drive the vehicle now and see if problems crop up again. They said the slack adjusters would likely need replacement if it happened again right away. At $125 each for automatics manuals seem a lot cheaper at maybe $20 each.
The shop also checked the rear brakes and found that one of the tag axle slack adjusters is bad. It is a Haldex part, but rust has obscured the part number. They took it to four different parts places with no luck as it is somewhat unique. I ended up having to order one through MCI at 8:45 pm last night and having it overnighted. The part is at the shop now and the bus will be ready this afternoon. I didn't think to call Bryce last night to see if he could find a part number on his Dina. Maybe I could have saved the $77 shipping cost if I had a Haldex part number.
I am going to ask for the adjuster back so I can find someone who knows if it is really bad.
I thought what C&J Bus Repair was doing for me was a brake inspection, but he said all they were doing is checking the stroke and lubricating everything. He said a brake inspection takes them two hours. I might just take the bus to this new shop for brakes as they charge 25% less.
It wasn't until I took the bus out for a drive Monday morning that I realized there was a brake problem that seemed to be getting worse the more times I had to brake. I found a shop that could look at it Monday evening or Tuesday so I took it there and they looked at it Tuesday afternoon.
In retrospect, I should have had the brakes checked earlier and I wouldn't be getting things fixed last minute. I had assumed C&J Bus Repair was doing a full brake inspection.
It seems to me you jumped on me for suggesting that it was up to YOU to keep a check on your buses condition. IIRC, you said something of the nature of, "That's what I pay people for".
I have no sympathy for you. You refuse to look at the bus systems, other than the engine and transmission and hope that your 'yearly inspection' is good enough. Those slack adjusters didn't go bad in a year. They probably wouldn't have gone bad in 5 years if they were lubed and checked by the owner.
My thought would be to get on your @$# and crawl under the bus, looking at any and everything and fixing any single thing that looks like it could be a problem.
A shop cannot and will not check every possible problem. You wouldn't pay for it and if they asked you to, you scream bloody murder. The shop will do exactly what you tell them to and nothing more.
Every year you go through something like this........ You complain about heat, cold, wet, dry, late, early, anything but the lack of
your doing required maintenance. A shop isn't a panacea for your responsibilities. Repair shops are there to fix things..... not primarily to look for stuff that you should have found as an owner of a piece of heavy over the road equipment..
Quote from: belfert on August 31, 2011, 10:10:37 AM
It wasn't until I took the bus out for a drive Monday morning that I realized there was a brake problem that seemed to be getting worse the more times I had to brake. I found a shop that could look at it Monday evening or Tuesday so I took it there and they looked at it Tuesday afternoon.
In retrospect, I should have had the brakes checked earlier and I wouldn't be getting things fixed last minute. I had assumed C&J Bus Repair was doing a full brake inspection.
Cynic that I am I would get under the bus and see how much travel the brakes have. I would not rely on someone to tell me. 1 3/4 sounds almost too much. Around 1" seems about right without looking in the book.
If the travel is too much I would disconnect the hose to the brake chamber and using shop air give repeated shots of air to see if they adjust into the proper travel range. If not, I would replace them with a set of automatics. All they need is occasional lube so once new ones that work correct are installed they should last a life time.
Hard to imagine both going to hell at the same time. If in fact both are bad it suggests someone who worked on them previously did not know what they were doing.
Quote from: Just Dallas on August 31, 2011, 10:38:20 AM
I have no sympathy for you. You refuse to look at the bus systems, other than the engine and transmission and hope that your 'yearly inspection' is good enough. Those slack adjusters didn't go bad in a year. They probably wouldn't have gone bad in 5 years if they were lubed and checked by the owner.
Plain and simple, I understand the principles of how air brakes work. I don't know how to tell if the brakes are in adjustment or not. I don't have anyone to teach me.
My plan right now is to go to the Bendix brake school in 2012. I don't have the time off available to go to any of the remaining classes in 2011.
I've crawled under the bus many, many times. Since I have no real idea of what things should look like I can't tell if the brakes are adjusted right or not. The drums, pads, and some of the other parts were replaced in 2006 along with all of the wheel bearings. I asked some local bus nuts at the time if I should try to fix my own brakes and they said no I should take the bus to C&J Bus Repair.
I know that I don't know how to fix air brakes which is why I have asked C&J Bus Repair every year to check the brakes for me.
Brian, it's really really simple. the brake cannister has a push rod. The measurement is how much farther out the push rod sticks when the brakes are full on vs when they are off. All you do is get your bus aired up and chocked so it can't roll. Get to where you can put a ruler up alongside the push-rod and take a measurement from the face of the can, or the mount, to the end of the rod or the clevis jam nut. Doesn't matter which as long as you remember. Then go in the bus, take a stick of suitable length and jam the brake pedal on hard. Go back under the bus and do your measurement again. The difference is the push-rod extension.
Each cannister will have a legal limit for pushrod extension. My bus manual calls out 2 1/4" for the fronts and 3" for the rear DD3's. I like to see no more than 1 1/2" on the fronts and 2" on the rears. Now that is full brake pressure, not tugging on the pushrod. It should be fairly equal side to side on each axle, but you don't need to be precise. Within a 1/4" is fine.
I hope this helps a bit.
The other Brian
If it will help, if when the push rod on the brake chamber is extended such as when the brakes are applied (I just have my wife hold the brakes down for the minute or so it takes to look at them all) if the red ring is visible the limit has been reached.
A good rule of thumb is the total travel should be 1/2 of the limit which was correctly stated above by the other Brian.
Back in the good old days of non-automatic it was just a part of a chassis lube to adjust the brakes. Tighten them until they were fully applied (9/16 wrench I think was the size I used) and then back them off 1/4 to 1/3 turn. I used to spin the wheels until I knew how far to back them off without dragging. Then I just always backed them off the same amount.
Brian, everyone says it's easy, and it really is. However, it is possible to adjust things backwards and make it worse. I would suggest you take it to a pro now to get it adjusted. If there are no problems, it should be cheap. If there are problems, you'll get a diagnosis and estimate. Make a deal for them to let you watch and learn. As simple as it might be, you don't want to get this wrong. I have done that. Also, check Youtube. There must be videos of this available. Once you know, it's all good, keeping it there won't be a problem.
My concern is more about determining if I have bad brake chambers, bad slack adjusters, bad s-cams, or similiar. It would be difficult for me to tell a bad one from a good one. This is why I'm going to go to the Bendix air brake class next year even though I'll probably have to take a week off work to go.
I'm unclear why it is so much better to do this yourself instead of paying a professional? I'm guessing you guys do everything yourselves on your house, car, bus, and everything else you own. You must not go to doctors either because you should be able to do that yourself too.
I don't think it is necessarily better to do it yourself. If i am having something else done, I will tell them that while their at it, adjust the brakes. However, it is good to know how to do it in case you are wondering if they are in adjustment. Since you have questions about the general safety of your brakes, you should have a professional check it all out. Being able to manually adjust your brakes does not mean you are knowledgeable enough to recognize other issues. This is not an area to be guessing at. I don't see why you are putting this off.
Quote from: Lin on August 31, 2011, 03:00:54 PM
I don't think it is necessarily better to do it yourself. If i am having something else done, I will tell them that while their at it, adjust the brakes. However, it is good to know how to do it in case you are wondering if they are in adjustment. Since you have questions about the general safety of your brakes, you should have a professional check it all out. Being able to manually adjust your brakes does not mean you are knowledgeable enough to recognize other issues. This is not an area to be guessing at. I don't see why you are putting this off.
The bus is at the shop getting the brakes checked and fixed at this very moment. I am expecting a call any minute now to come pick it up.
Quote from: belfert on August 31, 2011, 02:38:45 PM
My concern is more about determining if I have bad brake chambers, bad slack adjusters, bad s-cams, or similiar. It would be difficult for me to tell a bad one from a good one. This is why I'm going to go to the Bendix air brake class next year even though I'll probably have to take a week off work to go.
I'm unclear why it is so much better to do this yourself instead of paying a professional? I'm guessing you guys do everything yourselves on your house, car, bus, and everything else you own. You must not go to doctors either because you should be able to do that yourself too.
I'm just here waiting. Hoping these guys beat up on you a bit more and you give up. As much as I'd like a DL3, I'd be happy to take that Dina off your hands. In fact, I won't even charge you for the privilege! Guys: Keep wearing him down. Eventually he'll cave and I'll get a nice bus. With professionally adjusted slack adjusters, no less.
I just had a nice newboiler / domestic hot water unit installed here at our new house in Chicago. It took two professionals two days to complete the job. I guess I could have done it myself and saved a bundle. Of course, they didn't have a learning curve. They show up and do it. Maybe I could have gotten it done with 60 or 80 hours and 20 trips to Home Depot. Not to mention all the frustration. And that's assuming I did it right. And didn't expand the scope of work into a 120 or 160 hour job.
Sometimes there's more value in knowing what I don't know than knowing what I do know. And no matter how little the task, if I'm not comfy in doing the work, there's no shame in "outsourcing."
Just keep on fighting the fight. And when you give up, I'm here for your coach. ;D
-jbn
Its been a few years since I tool my air brake course but if I recall they taught us that it is the DRIVERS responsibility to check their air brake system EVERY DAY. So that tells me that everyone should know HOW to check it. Not necessarily how to fix it but how to adjust the slack adjusters. But perhaps that isn't universal and only applies to people in B.C.
When Brian gets through with his Bendix Course he will know how to repair everything on the air brakes heck he will even be able to tell you about ABS brakes, that is a good course Brian the manuals are worth the price all bus owners should take it
good luck
No, it applies to every driver of an air brake equipped vehicle that runs commercial. Now I need, and have, a full commercial license to drive my bus, I'm licensed to drive commercial anywhere in North America and I took pretty much the same course and test that you did to get the license. But a lot of people think that paying someone to do a daily inspection once a year is good enough. Buses are different - they get monthly full inspections of the chassis, because it isn't really possible to do a proper daily inspection on a bus without a pit. But the principle is there - you need to understand your equipment and know how to inspect it. Not necessarily fix it, but absolutely inspect it.
I am a big fan of taking the course, and I think that Brian will find that doing the routine work is not at all hard once he gets shown the ropes. Tedious, sometimes sweat-making, but not hard. I didn't know how to do it till I was shown either, it's just part of learning. Nothing wrong with not knowing, before you learn. It ain't rocket science, and it ain't Doctor of Medicine either.
Brian
FWIW the reason I would check my slacks if the were autos is that it seems pretty easy to screw them up if you don't know what you are doing. A grease monkey who did not know the specifics of your buses slacks could inspect therm find them of spec, mess with them trying to adjust them, f..them up then say, "hey Budd you need new slacks".
As far as all the other guff from the guys, hey guys go easy on him, he keeps it lively here each fall as the date approaches....don't really understand why Belfert's other rocketeers are never there helping prep the bus though.
Brian,
As a matter of fact I don't go to the Dr.
Unless you count back in April when I was doubled over in pain so bad I couldn't eat, sleep, walk r almost talk for 3 days before my parents insisted I go to the Emergency room or they'd call an ambulance.
4 hrs in the ER and they couldn't find ANYTHING wrong with me sent me home with pain killers and antibiotics an told me if I wasn't any better in 72 hrs to come back.
all said cost me $3000 for a couple bottles of pills I coulda gotten for about $300
;D BK ;D