Brakes Act Funny in Reverse

[jav9956]

I appreciate all the info and warning. I understand this is a critical part of the bus in order to function properly, thankfully that at least does not go over my head  .

At this point I do not drive the coach around, the most that I do is turn it on and pull it out and reverse it back in. Now that the build is starting to progress further I want to work this into my specific working knowledge of the maintenance and safety inspection of the bus. I do not just want to do one brake, I want to inspect them all, but I will be starting with the one that has made it evident that there is an issue.


I don't know of anyone in the area who would know how to do this; it would be great to get a walk through on it but this board may be the only option I have in terms of tapping into someone's expertise. I will try to take detailed enough pictures to post here so that you all can see the slack adjuster.

Maybe this is an easy point that just went over my head, but if you adjust one slack adjuster why would you have to adjust them all? As I said, I would like to for peace of mind. However, it seems they operate independently of each other so how would the amount of slack on one effect the amount of slack on another? I don't quite understand that.

Is there an easy way to determine between an automatic slack adjuster and a standard slack adjuster. I am assuming one would have an extra mechanism making it automatic, is that visible so that I can perform easy inspection to determine which one I have? As mentioned, I will also take pictures.

[buswarrior]

Auto slacks were an option for my 1975 MC8, Saab was the manufacturer, looked a lot like the Haldex of the mid 90's....

Saab? Those Swedes are into everything!

happy coaching!
buswarrior

[eagle19952]

well here you go Google is your friend... mine require a 9/16 box end wrench

https://www.youtube.com/results?search_query=slack+adjusters+air+brakes

ps i would not own auto adjust slacks 

[jav9956]

Of course youtube would have something! Thanks  

Saab... that is all my roommate drives, he has five of them! He cranks on them himself, all he likes  

Almost sounds funny having to adjust automatic slack adjusters, not so automatic then are they 

[gumpy]

Maybe this is an easy point that just went over my head, but if you adjust one slack adjuster why would you have to adjust them all? As I said, I would like to for peace of mind. However, it seems they operate independently of each other so how would the amount of slack on one effect the amount of slack on another? I don't quite understand that.

Your brakes need to be adjusted equally on both sides, as well as front and rear, although that is not as critical as side to side. If you only adjust one side, then when you apply pressure to the
brakes, that one side will engage before the other, and can cause the vehicle to pull to that side more than the other. In a panic situation, it can be so bad that you actually lose control of
the vehicle. Equally adjusted brakes will apply pressure equally on all wheels, and will keep the vehicle in a straight line during a panic stop.

[jav9956]

That make sense. So you basically want to tighten down and back off the same on both sides of the bus. I am guessing the only reliable way to know exactly what the slack adjuster is set to would be to set it yourself, there is not a way to visually inspect this? For instance, I can't simply go to the drivers side steer tire, measure the distance, and then set the same distance on the passenger side steer tire?

[Oonrahnjay]

    I think your problem is that a clown adjusted your brakes last time. 

[bobofthenorth]

I don't know of anyone in the area who would know how to do this; it would be great to get a walk through on it but this board may be the only option I have in terms of tapping into someone's expertise. I will try to take detailed enough pictures to post here so that you all can see the slack adjuster.

There's no substitute for having a buddy looking over your shoulder.  Any truck driver SHOULD know how to adjust manual slacks but there's plenty of truck drivers who are just steering wheel holders.  If you know someone who has gray hair and a CDL he should be able to show you what to do.

[kyle4501]

Auto slack adjusters work best when used every day. In the case of motorhomes where we replace tires based on age, not wear - the brakes aren't used enough to create the wear needed to keep the auto adjusters exercised. The lack of movement allows the grease to harden & that hardened grease prevents the mechanism from indexing.

That is why some prefer manual adjusters.

Welcome to the madness.

[brmax]

With some safe clearance underneath the bus, like on ramps and blocked for sure.
Its possible to take a look at the slack adjusters, and the automatic types will have a small bracket attached to it in some way, many are L shaped with a slot with a bolt fastening it and also to something else stationary like a pipe/tube.
This bolt is also used in initial setup adjustment.
All that aside when the air is built up to governed cut out setting, and several wheels blocked. If checking the rear have many wheels blocked to secure bus movement and adjustment should be checked with park brake "not applied"
You can have someone apply the brakes and watch the chamber rod move through its travel, this part is a measured area of DOT inspection.
If you can put a piece of tape around it for temporary measure or install some orange plastic things designed for the purpose, anyway mounted against or taped next to chamber housing.
So when the brake is applied or manually applied carefully with pry bar the distance can be measured between chamber housing and previous applied tape, giving a figure for record and or adjustment.
my best 2 cents, probably to download a manual for it. 
good day there
Floyd

[Scott & Heather]

Man I wish I were closer to you. If you can take some pics of your adjusters and post them here it would be awesome. You're really good at posting pics here...curious now whether you Haw autos or manual


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[eagle19952]

Of course youtube would have something! Thanks  

Saab... that is all my roommate drives, he has five of them! He cranks on them himself, all he likes  

Almost sounds funny having to adjust automatic slack adjusters, not so automatic then are they 

two reasons...no one greases them as thy should with the right stuff, and kinda like a Harley Davidson...if you want to be one with your machine you gotta roll in the mud..the blood and the beer

it sucks to find out the auto slacks failed when you are running into the @$# end of a school bus full of 1st graders... just sayin, i don't trust them...

[eagle19952]

That make sense. So you basically want to tighten down and back off the same on both sides of the bus. I am guessing the only reliable way to know exactly what the slack adjuster is set to would be to set it yourself, there is not a way to visually inspect this? For instance, I can't simply go to the drivers side steer tire, measure the distance, and then set the same distance on the passenger side steer tire?

simply put no... but there is a maximum travel measurement, there is no minimum  i run mine tight as tight and back off 4-5 clics and go by drum ring...but i bet i've adjusted 5000 rigs... not wheels. and 80% of those while dump truck drivers were eating lunch... in the mud.. on Sunday's, uphill both ways during grade school
PS you can replicate the slack travel by using a crescent wrench as a fulcrum prying the direction of application..

[MB LeMirage]

You can also buy a little tool called a brake buddy, it is the adjusting wrench and safe pry bar for manually stroking the chamber all in one tool. Cheap and helpful.
Ryan.

[eagle19952]

You can also buy a little tool called a brake buddy, it is the adjusting wrench and safe pry bar for manually stroking the chamber all in one tool. Cheap and helpful.
Ryan.

never seen one... got a picture

http://flxibleowners.org/article-the-brake-system-an-airbrake-primer/