2000 Allegro Bus Freightliner chassis

[sfox888]

Do you have a picture of air brake adjuster on a 2000 Allegro Bus with a Freightliner chassis>

[kaypsmith]

Here is a youtube video on how to adjust an air brake, probably not the same chassis, but all that I have seen have been the same. Welcome to the forum.

 

[wolfe10]

sfox888,

Welcome to the FMCA Forum.

While watching a video can be enlightening, there are a LOT of other things that need to be inspected/done to safely adjust air brakes. 

Be sure coach is blocked with the proper safety stands.

Inspect for oil leaks.

Check for heat checking in drums and shoes/disks/pads.

Proper lubrication which varies widely depending on brakes.

Said another way, this is not where a shade tree mechanic should start on a coach.  Now, if you are a trained tech and just new to air brakes, very happy you are interested in learning to service your own chassis.

[sstgermain]

I thought they were automatic on the Rv chassis

[obedb]

Automatic slack adjusters have been mandated for many years. If they are not kept properly greased, they will eventually no longer be automatic. They can be manually adjusted, but you have to know what you are doing. One type is easily abused by a well meaning do it yourselfer.

[richard5933]

Wow - that tapping thing is unique, at least to older vehicles like ours. Our manual says to tighten till drag is felt and the back off slightly until the wheel turns freely. No mention of tapping anything for sound checks.

My point isn't really to tell anyone how to adjust their brakes - my point is just to point out that specifications for each make/model are different. It is vital that the specific manufacturer's adjustment procedure be followed.

I think that it's important that everyone have a working knowledge of their braking systems for emergency purposes, but if you're not comfortable doing this and don't have the knowledge and/or equipment to properly block up the vehicle please leave this to a professional shop.

 

[sstgermain]

13 minutes ago, richard5933 said:

Wow - that tapping thing is unique, at least to older vehicles like ours. Our manual says to tighten till drag is felt and the back off slightly until the wheel turns freely. No mention of tapping anything for sound checks.

My point isn't really to tell anyone how to adjust their brakes - my point is just to point out that specifications for each make/model are different. It is vital that the specific manufacturer's adjustment procedure be followed.

I think that it's important that everyone have a working knowledge of their braking systems for emergency purposes, but if you're not comfortable doing this and don't have the knowledge and/or equipment to properly block up the vehicle please leave this to a professional shop.

 

So you jack up the rear of the RV . . . Have to put it in neutral and hope you can turn the rear wheels till you feel drag??? . . . Then back off. This makes absolutely no sense to me.

Maybe done that way if you are having a brake job done and that is initial adjustment.

[richard5933]

1 hour ago, sstgermain said:

So you jack up the rear of the RV . . . Have to put it in neutral and hope you can turn the rear wheels till you feel drag??? . . . Then back off. This makes absolutely no sense to me.

Maybe done that way if you are having a brake job done and that is initial adjustment.

That's the way it's done each time our coach needs adjusting. No way to safely get under without blocking the suspension, and there's no way to reach the adjusters without being under the bus. I could jack/block it myself, but fortunately I'm able to take it to the shop. They raise one end, use jack stands to ensure safety, and then go under on a creeper. With brakes released and transmission in neutral it takes just a few minutes to adjust, spin a tire, adjust some more, and then do the final spin check to be sure there is no drag. Then on to the other end. In a pinch when the only way possible to gain access underneath is with a ramp, the procedure would be to fully snug up the adjusters and then back off a certain amount. On our coach it's 1/2 turn.

The whole process is infinitely easier with a service pit to drive over, which is most likely how things would have been done 'back in the day' when a coach like ours was in commercial service. Ownership of a bus conversion like ours is not for the faint of heart or those unwilling to either do the work or pay to have it done.

Again - I wasn't trying to give instructions on adjusting brakes. I was just trying to point out that every make/model has specific requirements and that following a one-size-fits-all video probably isn't the best approach.

[kaypsmith]

With auto slack adjusters, a hard application of the brakes is when they adjust themselves. Best during pretrip preparations, while on level ground so that the coach doesn't roll, disengage the parking valve, apply the brake pedal hard as close to the floor as it will go, hold it there a few seconds then release. Of course you want to be fully aired when doing this. Also frequent lubrication of the auto slack assembly is a must. I bet that Byron, Bill, and Brett are all aware, but I wonder how many others are.

[dickandlois]

Kay, The list most likely is much longer., but air brake operation is one of those steep learning curve items for most First time Diesel coach owners and I will say it is one of the MOST important items to understand. A different world then Hydraulic systems.

Rich.

[richard5933]

19 minutes ago, DickandLois said:

Kay, The list most likely is much longer., but air brake operation is one of those steep learning curve items for most First time Diesel coach owners and I will say it is one of the MOST important items to understand. A different world then Hydraulic systems.

Rich.

I suppose that all this is part of the reason that some states are starting to require an upgraded license to drive the larger RVs. I wasn't able to get the air brake endorsement on my CDL until I could pass a basic knowledge test on the subject. It's probably a good idea for everyone driving a vehicle with air brakes to get a copy of the air brake manual from their state's DOT and learn the material, even if it's not required reading/testing for them.

[jleamont]

Keep in mind as Obedb mentioned, If they are not kept properly greased, they will eventually no longer be automatic. With that being said when they no longer are automatically adjusting its time to replace them. Its actually a federal law that its unlawful and illegal to adjust an automatic slack adjuster because it was out of adjustment.

Here is another good article;

http://www.hpw.gov.yk.ca/pdf/12_CommercialVehiclesHandbook_Ch9_part-4-FinalWeb.pdf

 

[kaypsmith]

Joe, that's great info, glad this subject came up!

[jleamont]

6 hours ago, kaypsmith said:

Joe, that's great info, glad this subject came up!

Glad to help, cant tell you how many times this very subject has burned us at work and I have had to go to court on it .

[obedb]

If you decide to take matters into your own hands.,  snug the adjuster up and then back the adjuster off about 1/2 to at most 3/4 of a turn. Whoever told you to jack the axle up does not live in the real world of 22 inch wheels.🤔🙄 Was done the way I described before auto slacks existed ( yes I am older than dirt ). The Bendix brand can be damaged if you don't release the operation of the accompanying pawl by lifting it up or out with a screwdriver before backing the adjuster off 1/ 2 or so turns . Has always worked for me before and after auto slacks.

JACK UP THE AXLE FOR BRAKE ADJUSTMENT 😂   Gotta be kidding!

[manholt]

In August, when  we are in Europe, Texas Custom Coach is not only doing  my brakes, but also replacing my seals and bearings !

[kaypsmith]

One thing to always remember, whether you jack up the coach, or don't jack it, always block the chassis, even if you have leveling jacks, before crawling under the coach. I've been around too many that did not do this, and they are not still around. It doesn't take but one fall to mame or kill a person, none of us want it to be you.