foot valve air leak

[newk]

thanks everyone for there replys,i just have to figure out how to get my big belly into that small compartment. i can feel the air comming out of the bottom hole

[zubzub]

on my '04 there is an access hole in the cockpit about 10" aft of the brake pedal
p.s no matter what size of belly you have you will have trouble getting into that compartment,,,

[Joe Camper]

Newk I still am unclear is it leaking when the pedal is applied or when it is just sitting.

If you say you can feel it out the bottom that tells me you are  leaking without the pedal applied and that may or may not be the footvalve itself.

Still unclear.......... is someone helping you and pushing on the pedal while your underneeth looking around or is it leaking just being parked??

[newk]

no one is helping me. i can feel air comming out of the bottom of the valve and there is a black oily residue on the bottom of the valve

[zubzub]

Have you drained your 3 tanks etc since you got the bus?  The tanks on 4104s seem to really get neglected.  I have no trouble imagining a system absolutely full of oil and water after decades of neglect. to wit on mine my 2 were rusted out/bypassed.

[Joe Camper]

OK then before I loosened 1 fitting or 1 bolt on the brake pedal I would go to the R-12 valves located directly at or around each axle (any decent truck mechanic could point them out) and remove the air line going in the top of them. Spray the fitting with soapy water and if it begins to bubble replace that first and see if the leaking out the exhaust port at the underside of the foot valve stops.