Parking Brake

[phorner]

I was off to the tire shop yesterday and before I pulled out of the lot I checked my brakes and found a couple of problems.

While performing the brake test I pump the brake pedal to release air pressure with the bus at idle and in neutral to make sure the low pressure alarm goes off. Well, yesterday it didn't, although the warning lights on the gauges came on as they are supposed to. Is the warning buzzer easily replaced? I'm guessing mine is the original.

Also, the emergency brake didn't "pop" as it used to.... it just kind of eased up and at nearly zero pressure. Again, I'm confident that my parking brake assembly is original. How much of a project is it to replace the parking brake valve?

That's the bad news.

The good news is that if you don't perform the test...... you won't know there might be a problem lurking.

The brakes worked fine while driving, by the way...

[Denny]

Paul,
The brake test should be performed with the engine off and with the key on. At idle, the engine is constantly building air pressure and you will not get a true reading. My parking brake valve, called a PP-1 valve, would leak air so I had it replaced last week when I had the 365 tires put on at Elite Coach. Part cost about $55 and took only a few minutes to do.

[Jon Wehrenberg]

Paul, The buzzer is easy to replace and is accessible. If the lights are coming on, check for power to the buzzer. If it has power but no noise it's the buzzer. The valve should not ooze up, but should pop up with a little authority. But Denny is right. If the engine is running you may be holding the pressure near the point where the valve should pop up by virtue of compressor output being near equal to the rate of depletion. That valve is simple to replace but on my coach I have some converter installed pieces to take apart so I can get at the fittings on the back of the valve and with the seat in the way and the cabinet wrapping around that area I don't have a lot of room to work.

[phorner]

Thanks, guys for the responses. In my zeal to get out on the road I forgot to shut down the engine prior to the brake test, so it sounds like you're on the money regarding the engine compressor being active.

Jon, I have taken the access panels out of the way so I can eyeball the valve in question. Liberty did an excellent job of making maintenance of this valve difficult, at best. But it looks like a simple job to replace it once you get it out.

Looks like it should drop out from the bottom once the securing nut is removed, but how do you remove the yellow pull/push tab? Looks like nothing is going to happen until I can get that tab off.

Anybody tackled this one?

Suggestions?

[phorner]

OK... looks like I found what I'm looking for.

The button is held on by a small roll pin which must be driven out with a punch for removal.

Found some general info attached...