Air leak from brake exhaust

[Robert & Dianne]

Found it...the air leak that is!
It is from the brake valve exhaust. Sometimes it is minor..almost no leak at all and sometimes it is full strength until the air runs out. Seems if I move the exhaust hose the leak either speeds up or slows down.
Is it time for a new valve or is something else causing the air to escape?

Thanks

Robert

[Friday1]

Originally Posted by Robert & Dianne

Found it...the air leak that is!
It is from the brake valve exhaust. Sometimes it is minor..almost no leak at all and sometimes it is full strength until the air runs out. Seems if I move the exhaust hose the leak either speeds up or slows down.
Is it time for a new valve or is something else causing the air to escape?

Thanks

Robert

So when you apply the foot valve you have a leak at the foot valve exhaust port? Or when you are not pushing on the treadle, it is leaking? If you get a leak when you are pushing the treadle, you could have backfeed from a bad rear brake chamber.

Rick in Ohio

[Robert & Dianne]

How I found it was pushing on the brake (actually pulling from front of bus through access opening) When I pushed down on treadle air would exit through exhaust hose....so I then knew where the hose went. Then when not depressing brake pedal I got a small amount of air through exhaust and if I moved the hose the amount of air escaping seemed to be modulated. I knew air was escaping through hose because several times last year after turning the bus off I could hear the air and would lose all pressure in the bus. I identified the hose it was coming from but it was until Sunday did I know where hose went.

Robert...in RI!

[Randy Dupree]

theres a rubber hose coming off the treadle?

[Robert & Dianne]

It is a 1/4in..maybe 3/8 hard plastic straight tube. Bottom of tube is level with foot step in bumper and about 10 inches back from right side facing bumper step or under brake treadle valve.

[Bill Pape]

Plastic line?? This may be the solenoid for the Horton fan, If it is accessible & plastic, remove and cut a new end & reconnect

[Randy Dupree]

we need pics of this hose and where it goes.
I have never seen a plastic line on a treadle valve on a Bird.

[Friday1]

I have seen treadle valves with a female pipe thread in the exhaust port before. Not too common. Usually the exhaust with oily mist would go somewhere it wasn't supposed to go so the hose was installed. These hoses were big like 3/4" ID. A small line is not big enough to exhaust a brake application.
If you have rubber flex lines in the rear at the brake chambers, you can take a pair of vise grips and pinch one of them off, make a brake application and see if it cures the leak at the treadle exhaust port. Try both sides and see which one eliminates the leak and you have isolated the bad one. I used to carry a dime in my road call tool box that was bent enough to seal off the flare fitting on a chamber so we could get a fire truck with a bad chamber across town to the shop. Nobody wanted to change a chamber in the street with cars whizzing by. Of course it would disable the brake at that wheel but you just drove slow.

Rick in Ohio

[Robert & Dianne]

Thank you all

As I said above. The reason I thought this went to the treadle valve was that it had air escape when I depressed the brake.

Bill when you say cut the end I don't think I understand. The end is smooth and this tube has always been straight. It has no curves in it and it is rather stiff so I think I would see if it was ever bent. I will be back at the bus on Saturday and will try to take pictures. Problem is it is very hard to see where it goes ...so many wires and tubes in the way.

[Bill Pape]

We are guessing, will wait for pictures