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Here we go again
Replaced all Norgren valves about 3 years ago. Replaced level low 5 stack valve about a year ago. Coach has stayed up without the leans until a couple of weeks ago. Went through the soap a bubble routine and did find a few small leaks at the fittings that I fixed, but front end is still lowering over a 5-6 day period.
In studying the drawing (see attached) the only thing I can think of is the leveling valve which is still the original. It is just the front going down and it takes 5-6 days so it’s a slow leak. What am I missing? Both front sides go down equally so it is something that connects the two sides with the ignition in the off position.
P.S. All air bags were replaced about 4 years ago
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
25 Replies
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Don Beard just had a post on his leaky ride valve and put a balloon on the exhaust port to see leak
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Chuck check to see if you have air coming out the exhaust port of the level low valve in the steer compartment. If yours is open, you will need to put a plug in it. Don’t tighten it all the way, then soap it up.
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
Thanks Art, good idea
I did that to find the leak on my shuttle valves for the brakes. Don’t know why I didn’t think of it for the ride height valve.
Chuck
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
Hay Mike:
Think I will do the balloon on that one too.
Chuck -
was also leaking where the shaft for the arm comes out the main body of the ride height valve.
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The Norgren(s) handling the front should stop all air so ride height valves are out of the loop.
Keep in mind however my experience is with Liberty and they modify the Prevost system so what I say may not be worth anything.
The ride height valves should be out of the loop however because with the key off if they are seeing pressure they will try to raise or lower the front end after the bus has been leveled.
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My dose that only when it is real cold to cold for me to find leak in summer it will stay up 3 months in winter a couple days 2 4/4 blocks fixes that
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
I’ve owned our bus/mh for 11 yrs. WOW!I haven’t looked for aux system leaks in almost 10 yrs because the leak rate has been acceptable, until late this yr. So, I gone over most everything, found a lot of small leaks. I also found 2 larger leaks: a) the belt tensioner regulator, b) and the 3 way red handle valve next to the regulator. Now I have the aux system leak rate down to 10-20psi/hr which is acceptable to me.I haven’t replaced the 2 low level Norgrens in about 10 yrs, so they’re on my list. I did put a ballon on the one with the exhaust port and nothing was leaking.The 2 Liberty installed Norgren on the floor of the steer bay for their auto leveling system are on my list, Each has an exhaust port I’ll do the ballon trick too 🙂I’m tempted to do what Jon did/does and add ball valves and pressure gauges everywhere to isolate leaks and/or things.
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Well its been two days now since I tightened the loose fittings I found and the front end is staying up. But on the other side of the coin… I live in central Fl and it has been warmer the last few days too. Dan you might have something with the cold temps because it was during our recent cold snap that I noticed the front falling.
Jon: I have a pretty good basic understanding of the air system but what is puzzling me (perhaps not understanding the air system enough) is when the key is off the air is locked at the two Norgrens on either side of the ride height valve, see drawing in first post (correct me if I am wrong). If the air is locked at the two Norgrens on each side of the ride height valve, one for the drivers side and one for the passengers side, why do both sides of the front go down? Not understanding where/how the two are connected with the key off.
Don: I didn’t bubble check the shaft of the ride height valve, looks like another trip under the bus. Got my Aux system down to about 5-8 PSI Hr. In almost 6 years of ownership have never been able to get it less than that.
Chuck
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Jon is spot on… The leveling valve is out of the loop because the Norgren valves “lock” all air therefore your front end drop is the result of leaks elsewhere:
The two Norgren valves can leak internally and not be detectable, its fittings, the air bags themselves and their fittings, the ping tank itself, its fittings and drain valve. Also, the top Prevost installed Norgren on back wall of steer bay – it can leak internally or its top fitting.
Those three norgren’s, the two airbags, the two ping air tanks and ALL attached fits & drains are the only components that can leak causing a front end to go down with the key off.
****Question for you… Were the fittings you found to have small leaks… were they push-in or compression and how did you resolve their leaks?
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P. S. There was a “bad batch” of five way norgrens a few years ago… Wonder if you (like me) got one of those and it failed….
I have also had (only) one 3 way fail similarly far too soon and with no evidence of contamination etc -
maybe a simpler look that shows how the HCL can not contribute to a leak down in an IGN OFF situation. Note all norgrens shown in their normal state (no pilot air) which for the two controlling the steer axle bags are ‘Normally Closed’ which ties them to each other and to the top norgren in the level low area under the drivers seat.
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Jeff:
I have changed all my fittings to compression over the years, so answer to your question is compression fittings. I tightened the nuts on the compression fitting to stop the small leaks.
Clint:
Your drawing is excellent and I think solves my problem. I put small balloons on the exhaust ports of the leveling valve and the Norgren in the steering compartment about 12 hrs ago. As you can see from the attached picture the balloon (circled in red) is starting to inflate (it’s been a slow leak that takes 5-6 days to drop a couple of inches). I will check the balloon again tomorrow to see if it has inflated any more.
Do you have the drawings that show the valve configuration with the key on? The drawing you attached really simplifies how the key off works.
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
Chuck, Jeff answered your question.
This will be no help, but might be of interest. An air bag leak at the bottom of the air bag behind the “piston” is undetectable. You cannot soap it because you cannot see it or get at it and because of the rubber an ultrasonic leak detector cannot “hear” it.
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Jon:
I am thinking it is the top Norgren in the steering bay, it is an original that has not been replaced. See above post ref balloon inflating.
Chuck
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