foot brake valve

[newk]

what is the easiest way to change the foot brake valve in a 4104. the one in my 04 is leaking air thru the diaphram

[wildbob24]

The easiest way would be to pay someone to do it for you. 

Bob

[JohnVickrey]

Bernie,
Bob is probably right but you can do it.  I suggest a E6 valve like this http://www.anythingtruck.com/Merchant2/merchant.mv?Screen=PROD&Category_Code=HTP-AIRB&Product_Code=322-E6COMPLETE

There are enough parts to modify your current brake and throttle pedal.  You will have to change the lines around but that is not a problem.

I had a OEM valve but I gave it away and used the parts listed in the link above. 

If you have questions call me.

[luvrbus]

Just asking but why a dual circuit valve on a single circuit system I can't see the benefit ? I know it is done from time to time

good luck

[JohnVickrey]

why a dual circuit valve ?

Cause that was the only one I could find, that had the pedal.  There may be a single circuit available.   Bernie got the idea and I'm sure he will improve it. 

[luvrbus]

I was just asking thanks for the answer I thought there may be a benefit of doing the change and I couldn't figure out what fwiw I never have trouble finding a E2 valve

good luck

[robertglines1]

Is the foot brake valve your talking about like the ones used on old military trucks?/has pedal mounted on valve?  just curious.   Bob

[Joe Camper]

newk if your foot valve is leaking it may or may not be the valve itself.

Are you talking about a leak when appling the brakes or just sitting coming out the exhaust port.

If its leaking out the exhaust port out the bottom when not applied the following applies.

When it is depressed it is sending a signal to the axles where there are relay valves that get activated by that signal coming from the pedal and they in turn open and direct air directly from the brake air tank to the brake diaphragms at the wheel. This eliminates fade and delay and is just the best safe way to stop.

That relay valve usually a R-12 (unless you have antilock) and is a diaphragm type valve and if it leaks it will release brake tank air out the exhaust of the brake pedal thru that signal line. This also could be a overlooked thing when your trying to tighten up the air system on a bus that looses brake tank air while sitting parked not running and cant figure where its going.

Usually those are easy to get at and are 40 or 50 bucks.

The signal linel from the pedal will be the 3/8 plastic (usually) but always the line going in the top of the relay valve. You have 1 for each axle. 1 by 1 remove that line going in the top of the r-12 and spray the fitting with some soapy water to see if there is air comming out the top port on that valve, it should not. That's 1 way to check if you were so inclined.

Hate to do that brake pedal and still have the leak

[buswarrior]

newk is going to have metal lines to the foot valve, if it is still stock. Re-arranging the lines is going to be a big job.

It would be easiest to get a direct replacement.

I agree with Joe Camper, confirm that the relay valve is not bleeding back first.

Take lots of pictures to aid you in re-assembly, and take whichever valve is the bad one with you to the parts place to get the right one.

happy coaching!
buswarrior

[zubzub]

FWIW on the 4104 if re plumbing is required it is usually easiest to get rid of the copper tubing and use plastic.... apparently one is not supposed to splice into air lines but as the plastic is so much easier to work with, running a line from the from the main air (before it goes to the aux tank...I think that is where the supply to service brake is on my '04) will be easy.  Good luck...also if you can find a direct replacement it will be easier, and of course as the others said,make sure the relay is not back feeding your service brake valve....

[Flatspot]

Newk
I don't know if you have a foot valve that is mounted on the bulkhead accessable from the access door on the road side of the bus.
It has a roller and linkage on it. Make sure that all of the external mechanism is free to operate, especially the roller, so that the foot pedal returns all the way and is not being partially held down. That also goes for all the floor area around the pedal it's self. Crud build up over the years will keep the pedal form returning all the way.
I don't know if the catalogue E2 valve will work. I know when I redid mine some years ago I got a rebuild kit from B/W parts house.
I know times have changed and I've also gotten parts from Luke at US Coach

Larry