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Topic: Likely air leak locations  (Read 3720 times) previous topic - next topic

Re: Likely air leak locations

Reply #60 –
Quote from: Protech Racing –
The brake chambers won't leak until the brake pedal is pushed.

Correct.  The parking brake/emergency brake is SPRING applied, AIR PRESSURE released.

So, when parked, should not be source of air leak.

Re: Likely air leak locations

Reply #61 –
Speaking of air leaks, I have a "waiting to happen" braided stainless steel air line from compressor to air dryer.  Is there a reason for it to be so long?  It comes out of compressor "I think it is compressor" goes forward to transmission then loops back to back of engine compartment across back to air dryer.  It has 2 spots That the stainless braid is missing-- looks like it was kinked!
Would a shorter line do the job? 
Thanks
Chris

Re: Likely air leak locations

Reply #62 –
Quote from: Chris m lang –
Speaking of air leaks, I have a "waiting to happen" braided stainless steel air line from compressor to air dryer.  Is there a reason for it to be so long?  It comes out of compressor "I think it is compressor" goes forward to transmission then loops back to back of engine compartment across back to air dryer.  It has 2 spots That the stainless braid is missing-- looks like it was kinked!
Would a shorter line do the job? 
Thanks
Chris
If that big air line was kinked its leaking. Its that type of  stainless nylon hose because of the heat produced by the air compressor. That type of hose can not be kinked no matter what.

Re: Likely air leak locations

Reply #64 –
Quote from: Chris m lang –
1. Is there a reason for it to be so long? 
2. Would a shorter line do the job? 
3. It has 2 spots That the stainless braid is missing-- looks like it was kinked!

Chris,
1.The short answer, yes
1a.  That hose length is there so the air that has been compressed can have time to cool off some prior to getting to the dryer. I don't remember the exact numbers that Mark (he is the Cummins man that worked on this engine development) gave me but that length was what was determined to work for the Holset compressor on our age coaches. Different compressor/dryer combos have different specs.
2. It  would do the job of moving the air from point "A" to point "B"
3, Not good.

Pamela & Mike

Re: Likely air leak locations

Reply #65 –
There is real satisfaction in finding a problem then creating a solution. When I had a significant air leak, I squirted my bubble mix all over and when I got to the front (engine running) I could clearly hear it. Reaching up to the bottom of the treadle valve, I found the leak and when I plugged the exhaust port with my finger I could make the engine rev! The replacement/ remanufactured valve was easy to get, relatively easy to replace, and it solved the leak.
Now on to the next thing...

Re: Likely air leak locations

Reply #66 –
Got back under the coach today and found a couple more air leaks.  One of the solenoids MoT replaced on the rear six pack is leaking around the base of it.  It may just be the o-ring but the surface of the manifold is so rough I'm not sure how they got a seal in the first place.  The other two air leaks are coming from the service brake relay valve and the spring brake relay valve.  They both look identical and from pictures I found they both look like a service brake valve but how I'm reading the schematic one is the spring brake valve. I could be wrong though.  Both have one air line entering and two lines running to the brake cans.  Both are leaking from the bottom around what appears to be a circlip. If there is a circlip, maybe they're rebuildable?  There are numbers on the bottom (T-294859-C) but I didn't come up with much of anything.
 Is anyone familiar with these valves?