leaning after shut down and brake problem

[edvanland]

OK on our MCI 7 after it has been shut down over night it will lean 4 inches on the left side. The air gauges on my leveling system show 80 pounds and the bags seem full. The air pressure builds up to 120 lbs and is a new compressor. Having problems with my brakes after this trip they don't want to stop the bus. Backing down the drive they would not even hold the bus when I put on the emergency brake. Have a new pre set 65 pound pressure valve I will be putting on one of the front air tanks I just received from Luke. Please only give pertinent answers. Any suggestions will be appreciated. As far as the brakes go there are no oil signs on the back side. They are all adjusted correctly and have very little wear on them I am going to go to a softer lining when I pull the shoes. I will also replace any parts of the braking system that even looks like it might be bad. Thanks in advance.

[Utahclaimjumper]

I'm wondering if your getting full pressure thru the foot pedal valve.>>>Dan

[bobofthenorth]

If the brakes don't hold when you dynamite them then it seems unlikely that they are in fact "adjusted correctly".

[luvrbus]

Check the rod distance it has to be on a 90 degree ,not saying you did it but a lot of people turn the slack adjuster the wrong direction adjusting brakes they will tighten like they are adjusted but don't work worth beans 

[chessie4905]

Maybe a bad or misadjusted leveling valve?

[ol713]

   HI Ed;
        When changing the front air tank,  check also the "E filter" that is located between the air

        tanks. that filter is often over looked.

                                        Good luck,  Merle.   

         P.S.

         The filter looks like a small ball of yarn>     

[Utahclaimjumper]

 I have found that the 90 degree angle that Cliff is speaking of is a huge part the the leverage needed to get correct braking action at the S cam..>>>Dan  ( This is the angle formed by the push rod and slack adjuster arm when fully applied.)

[Dave5Cs]

Hi Ed, question what did you do or have done to the air system and or brake system before this started happening?

[buswarrior]

DD3 parking air pressure confirmed? The new regulator from Luke will zero that maintenance item. It would  be nice to know what it is before altering the evidence. Your plain old tire gauge will mate to a male air fitting, get one of the drain valves with the threaded end to fit one, bonus is an airline can also be installed direct to the tank...

Yes, what work was recently done?
So, so often, it is the last work done that is the cause of new trouble.

If it used to stop and park properly, and suddenly it isn't, something or someone is to blame.

The travel of the brake rod stroke should be measured. Angles depend on the pushrod ha ving been cut to the proper length on install, and we all know there are precious few mechanics who do their work correctly... many a brake has been found at 90 degrees and the chamber bottomed out...

Be safe! How is this thing going to stop, or what do we hit if it doesn't, testing it?

Or, be running a camera...!

Happy coaching!
Buswarrior

[luvrbus]

The inexpensive little pressure protection valve  doesn't always work as designed they can be a pain ,download you a template for the angle and stroke from Bendix start there and work back ,You have been on the road to Mexico,Ca,Nv and all over Az with no problems has to be simple   

[Utahclaimjumper]

It can even be as simple as some crap getting under the pedal so you don't have full travel..>>>Dan

[richard5933]

I'm certainly no expert on either system, but it does appear that there are two problems here. The lean after shutdown would indicate a problem in the air system, but if it's got enough air to raise the bus and build pressure when running it should be affecting the brakes to this extent.

Not all leaks can be detected externally either. I had an internal check valve in one of my height valves fail, causing the air in the bags to exhaust back into the tank after shut down. The bus drooped but no external leaks were present.

The braking problem could be lots of things - were they working at some point and then suddenly stopped working or were they never working?

[luvrbus]

If the bus is level when driving he has a problem with the air level system that is showing 80 lbs more than likely the check valve 

[chessie4905]

"The air gauges on my leveling system"
Do you have some sort of auxiliary leveling system for camping or you referring to factory air leveling system?

[chessie4905]

"The air gauges on my leveling system"
Do you have some sort of auxiliary leveling system for camping or you referring to factory air leveling system?