Lexington, KY w/ MCI 102c3 leaking air

[aaronjweiss]

Hi everyone,
I'm on tour with my band, currently in Lexington, KY, driving a 1990 MCI 102C3. Last night we started leaking air underneath the parking break push/pull valve. When the parking break is engaged we don't lose air, but when we disengage it air shoots out from a part we found by climbing into the spare tire compartment (see photo attached). Any advice for a mechanic around here (who works on Saturdays) and/or possible DIY fixes?
Thank you!
Aaron

[Melbo]

I remember some guy on a roadside repair using a wine cork as a temp to get to a repair shop or home.  The details are sketchy in my brain.

good luck getting back on the road.

Melbo

[Tedsoldbus]

Hang in there Aaron. Some of the mechanics (I'm not one) will see this and know how to get you going. For now, be glad you beat the tornado and practice a few songs in the bus.

[buswarrior]

By "engaged" what do you mean?

Parking brake in parked position, or parking brake in driving position?

Are you able to get the bus to roll freely?

Happy coaching!
Buswarrior

[hogi6123]

There is a problem with something in the air lines for your rear brakes. Air is leaking from one circuit into another where it shouldn't be.  The problem is near the rear axle, inside a brake control or inversion valve, or one of the diaphragms in the rear brake actuators.  The venting at the front is just a symptom.

The first step is to find an air diagram for your bus.
Second step is to crawl under the rear wheels with a few big wrenches and find the source of the problem by disconnecting air lines and seeing which have pressure, and comparing it to your air diagram.  NOTE: You don't want to be squished by 30000 lbs so make sur the bus is supported safely first!
Third step is to remove the failed part, and rebuild it or get a replacement.
Fourth step is to put it all back together.

P.S. This problem has happened to others, you can find previous advice by searching this forum.

[hogi6123]

Was it freezing last night where you are?  That could possibly stop air lines from working correctly.

[aaronjweiss]

Thank you to everyone for posting these replies--your help and support is very much appreciated! We ended up finding a mobile mechanic who located the problem: there was a tear in a little rubber diaphragm within the valve assembly. He simply bypassed the valve as a temporary fix, and encouraged us to replace the diaphragm. So we're back on the road!
Thanks again,
-Aaron

[buswarrior]

So, what was bypassed, and what functionality has been compromised by doing so?

Folks need to learn from these posts!!!

There's no spare bits that aren't required under there...

When stopped, better block the wheels or park in a pothole.

Happy coaching!
Buswarrior