MCI-9 Squealing Air

[Brian Diehl]

Guys,

In the passenger side rear engine door, above the transmisson, are two air regulators.  The one on the right, is leaking.  Could this be my problem?  What does it take to rebuild this?


Thanks for the help.

Bill
Currently in Phoenix

Bill, the air regulators are a snap to rebuild.  The "book" even describes how to do it.  Call up US Coach Repair and order the rebuild kits.  Pull the regulator, replace the perishable parts and reassemble.  Then get out your shop air and a pressure guage to set the correct pressure and tighten down the lock screw.  Put the air regulator back on the bus and your done!
One of the simplest repairs possible on these beasts.
-Brian

[Kwajdiver]

Brian,

What's the number, will call you in the morning?

What about the other part that is leaking, does it have a rebuild kit?  That would be the part under the driver in the driver tool compartment.

Thanks,

Bill

[Kwajdiver]

Okay,,,,

Looking in the MCI manual.  I believe my big problem of this ungodly squeal of air leaking is coming from the R-12 Rear Brake Relay Valve.   Will go looking for it in the morning.

Any input on this is welcome.

Bill

[Tony LEE]

"In the passenger side rear engine door, above the transmisson, are two air regulators.  The one on the right, is leaking."

Just so you know, the RH regulator sets the tag axle suspension pressure - 35psi. The RH regulator is the tag axle unload pressure - 15psi.

To the left of these is a valve that switches between the two. Even if you don't have a tag unload switch on your Left drivers panel, the components may still be there.

If you check all the other regulators in the bus, you may well find many of them with slow leaks - usually quiet, slow leaks that add up in total.

Some of us have a dream about getting to the stage of having a leak-free bus (oil or air) -- but after a while the urge passes and you just get used to starting the engine a few minutes earlier and buying oil in bigger tins.

[Kwajdiver]

Tonylee,

Thanks for the laugh this morning.  I'm sure you are correct.

Also found the E-10 Brake Value leaking on the bottom.  Is this anything to be concern about?

Bill

[buswarrior]

Hello kwajdiver

The air leak out the bottom of the brake pedal valve occurs under what conditions? parked, released, pedal released, pedal applied?

Any leaking brake valve is NOT your friend.

My schematics have gone missing.... a leaking DD3 parking diaphragm will exhaust out of another service brake related valve, fooling you into replacing a perfectly good valve, only to find it "leaking" again. Probably the relay valve down the back is where.

If you want to have a go at rebuilding the valves or regulators, feel free, but you might want to price a replacement and decide if your time, and the risk of finding the casing damaged, is worth it.

I replaced those same tag axle regulators a few years ago, IIRC, $42 to replace each, kit was $22 each.

happy coaching!
buswarrior