Brake valve?

[chessie4905]

If you look closely at the ports, they have slightly raised sup and del letters. They aren't exactly in same location on ports. Look closely. Supply ports are 180° across from each other and other two are delivery ports, again 180° apart. Primary section is on top and secondary is bottom half. Secondary delivery goes to front brake relay valve. Primary delivery goes to rear brake relay valve. Other supply ports are either plugged, receive air supply from air tank, send air line to dash pressure gauge, or brake like switches, or low air pressure switches. There should be only one delivery port in use in both upper and lower halves. The other upper and lower del port should be plugged.
Hope this helps.

[buswarrior]

Late brain engagement...

Yes, a DD3 system can fool you into blaming the foot valve for a leak.

If there is a leak in the right places in the parking circuit, the leak gets into the service brake side, and then out the foot valve exhaust (or the rear brake relay exhaust, depending)

I have not thought about the specifics in a long time, and all the bus manuals are packed remote to me...

Bevans? How's your memory for some trouble shooting? Better to investigate and save messing with wrong part...

Happy coaching!
Buswarrior

[jmblake]

Thanks Chessie and BW Hopefully over the weekend I can do some more investigating, I honestly think it has something stuck in it from cleaning it up since I had no leaking beforehand, but anything is possible.
Thanks Jason

[buswarrior]

Correct troubleshooting strategy!

The last thing a busnut touched has a high probability of being the cause.

The rest? Bus demons, karma and God lightening up his default "fool protections" as the busnut becomes more educated... There is no such thing as coincidence in the life of a busnut...

happy coaching!
buswarrior

[luvrbus]

Only takes a grain of sand to cause you problems on air valves

[chessie4905]

Once you verify if brake treadle application valve is or isn't the problem, and all the other lines are in correct location then you can delve into the parking brake conglomeration that goes with dd3's. Mine has three inversion valves, single and double check valves and connecting lines associated with push-pull parking valve. A real cluster......

[jmblake]

Update, Problem solved , As per chessies advice I took all the lines off other than the supply lines and it still leaked through, so with the brake lines off I removed the supply lines and added some air tool oil in each and reinstalled then added shop air to the bus and worked the brake pedal several times and just let the air blow through the valve, and after doing this several times it stopped leaking. Put everything back together and it's not leaking and holding air So it must have had a piece of dirt either from me cleaning it or when I was changing the fittings around get in there and make it stick. Now I can get back to working on the generator slide out. Thanks everyone for all the tips and advice.
Jason

[Scott & Heather]

Cool beans. Free and easy fix!!


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