5A Air Leaks

[Fredward]

My 5A looses air after shutting down the engine in about an hour. The suspension holds for weeks but the gauge on the dash reads 30 psi after about 45 min and 0 within about 90 minutes. The three front tanks all hold air for days as does the wet tank in the back. I don't know what is connected to what part of the air system. It could be a windshield wiper valve or the door latch valve or the air gauge itself. I can't even locate the governor. What components should I check with my soapy water spray bottle?

Does anyone in the Mpls MN area have an ultrasonic leak detector?

Fred

[JackConrad]

    If it is like our MC-8, the dash gauge connects to the accessory tank. This means the leaks is very likely in the air wiper system or door lock cylinder system. Best bet is air up the bus, get a spray bottle of soapy water and go to work in the top of the spare tire compartmnet and under the dash.  Spray all air lines, air line fittings and anything the air lines attach to. Wiper control knobs and air wipers are common leak sources.
    Not sure which govenor you are referring to.  There are 2 govenors. The engine govenor, which controls engine speed is on top of the engine near the back door with the throttle linkage connected to it. The air govenor is bolted to the side of the air compressor near the top. Jack

[Fredward]

Thats exactly the kind of guidance I was looking for. And I meant the air governor. I've seen them on the bench, but can't locate it on the engine or compressor. Now that i know its on the compressor I'll look again. I've got a soapy water spray bottle just for finding air leaks. Thanks Jack.