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Strange “BIG” air leak
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Just a thought here..is it possible that your tag axle was over a high spot in the parking lot? If I am thinking correctly this would cause the leveling valves to begin exhausting air because the frame to drive axle distance would increase. If the tax was sitting on a big enough hump it could actually dump all of the rear suspension air to the point where the tag bags were on the stops and still not bring the coach down to the point where the leveling valves would be satisfied. Experts please jump in and correct me if my thinking is flawed. Jeff
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The leveling valve controls all 3 bags.
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Jeff,
I was parked level, and no change in ride height.
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It is not a brake issue guys. The gauges never moved and the aux gauge went to zero.
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About a month ago I was picking up my coach from having some repair work. While standing beside the drive/tag axles, engine running, we both heard a major air loss under the coach in that area. There is a pop valve on the bottom end of my air dryer, so I was told, that had failed open. The coach would not build air so it had to be repaired outside. I requested to have the old valve and it is now holding air.
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I have now noticed another clue as to what caused the leak mentioned earlier.
My bus has always maintained air pressure, no lower than 90 psi while in my shop. And, it has never sagged or leaned.
Now, air pressure is still up, but bus is now leaning down on the right rear. I don’t know if the above leak has something to do with this, or the colder weather. It didn’t do it last winter.
So, now that it’s leaning, would a Norgren be a possibility? Kinda unusual that both happened within a week.
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In the right rear you have several potential causes for the leans.
Air bags, the three port valve between the tag and drive axle air bags, the associated air fittings, and the five port Norgren that directs air to the air bags via the ride height valve or the from the air supply when controlling the height manually.
The five port Norgren is the “gatekeeper” and when the key is off it goes to the neutral position and “locks” the air in the air bags. Its leaks can be such that soaping it might blow bubbles if the leak is past the spool on the ends, or internal, in which case it will show up as air leaking from a 3 port Norgen in the front.
At least it is islated to one side which can sharpen your focus.
Having said that, if your pneumatic system is 10 years old or more it also may be a sign components are starting to experience some end of life issues, in which case chasing and fixing leaks bec omes a never ending project, one best avoided by just changing air bags, Norgrens and all push in air fittings with compression.
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I knew that was coming! Well, I’ve done it on the 2 previous buses I’ve had. Guess it’s time to start over on this one, get out the soapy water bottle, Fittings, and a visit to Jeff’s in the future.
I have not bragged on this bus before, even though I wanted to, because it has been leak free until now! And, it has Never had any fittings or anything done to the air system before. All original. It’s never been driven on salted roads, and has absolutely no corrosion or rust on anything. Always stored inside. Air pressure has always stayed up, even on the Aux side.
I knew if I bragged on it, it would start leaking…..oh well,…It’s like all the others now……let the chasing leaks begin!
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The good news is if you just start with the replacement of the components that tend to age you have a leak free coach all over again.
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Found the “leaning” problem, and it wasn’t associated with the “Big” leak I heard. It was a leaking drain valve on one of the ping or football tanks. Put a new one in, and now No leans………….for the time being.
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Jerry those are known to leak after time, anytime those are opened to drain a air tank they should be checked after the the tank is full again to make sure they are still leak free
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