air brakes leak

[silversport]

Just replaced the bellows on the mini-max (I think that is what it is called), cannot get one to seat (small leak when brakes applied), any ideas? Thinking about getting another bellows and trying again.

[eagle19952]

Just replaced the bellows on the mini-max (I think that is what it is called), cannot get one to seat (small leak when brakes applied), any ideas? Thinking about getting another bellows and trying again.

diaphragm
dog bowl
try re-seating it
was the piston retracted fully ?

[silversport]

Sorry, diaphragm , yes 6 inch dog bowl and I have reset it three times. The driver side no problem.

[chessie4905]

Service manual says to slowly tighten clamp bolts till leak stops. I'd add some lube to inside of clamp lip to allow it to slide and seat while tightening. Anti seize will work. Don't go crazy and snap bolts.Just till leak stops. They also say to use soapy water solution if necessary.

[robertglines1]

Have had luck with emery cloth clean up sealing surface.

[silversport]

Thanks to all, the anti- seize and a hammer did the trick.

[Jim Eh.]

A light dusting of baby powder on the diaphram aids in getting it centered. Also changes brakes squeal to crying but hey at least it won't leak.

[silversport]

Now that we are on the road the leak returned and it is strange only leaks when parking valve on, something big leak other time small. no loss of air with parking valve off.

[Oonrahnjay]

Now that we are on the road the leak returned and it is strange only leaks when parking valve on, something big leak other time small. no loss of air with parking valve off. 

     Sounds like a leak in (or around) that diaphragm to me.  Wait, "no loss of air with parking brake off"

[buswarrior]

What bus is this? MCI?

DD3 chambers? 2 diaphragms?

The smaller parking diaphragm is leaking.

Happy coaching!
Buswarrior

[bevans6]

His past posts indicate a 1962 GM 4106, I don't know what brakes that would have, or what it might have at this late date...

[luvrbus]

The parking brakes have probably been added to a 62 model 4106 most had the mechanical brake on the rear axle either the spring or DD-3 chambers work on those I am thinking he has the DD-3   

[Utahclaimjumper]

They are all standard 62 GM.>>>D

[chessie4905]

Maybe Silversport can report back whether his brake cans have two or three hoses to them. Them we can be more specific with our help.

[silversport]

Yes I have a 1962 4106 with I think they are called mini-max cans, there is one hose from the valve on the bulkhead to the can, the diagram is 6 inches and is connected with a two bolt clamp. I am on the road now hopeful I get some insight at the Western GM rally at Quartzsite. Happy New Year to all.