ziaptrn Posted October 30, 2022 Share Posted October 30, 2022 Hello all - Our new-to-us 2008 Monaco Dynasty with S-chassis has made a strange whistling/squeal-type sound from the right front area whenever the right frontair bag(s) fill(s) or exhausts air. I initially thought that the ride-height valve was making the whistling sound, so I replaced the valve in the front (1 valve for both sides of the front axle) and also replaced a leaky pressure protection valve. After that, I removed the front Valid leveling manifold and cleaned everything and replaced all of the o-rings, lubricating them properly etc. I have adjusted the ride heights spot-on to manufacturer specs and the coach drives like a dream. The auto and manual leveling features both work perfectly, and there are no errors on the control panel for leveling or anything else. The noise was present before the ride height valve, o-ring, and pressure protection valve replacements and persists afterwards, so the changes I made did not affect anything besides the leaky pressure valve. The bags hold air 5-7 days with no loss, and then very slowly after that. The issue is that every time we hit a bump or the front wheels moves up or down, a relatively brief whistle/squeal that clearly is made by air moving is produced. After miles and miles of eeeek-whine....eeeek-whine...eeek-whine.... this becomes very tiring to hear. The sound also is produced when the coach has been leveled using the control pad and then I press "Travel Mode" and the right side adjusts up to the proper height. The sound persists until the coach achieves the proper ride-height, then stops until the next bump or self-adjustment while driving, and then the eeek-whine starts again. I've checked the shock absorbers and entire front end (tie rod ends, etc.) and cannot reproduce the sound with movement alone. I have lubricated all of the zerks several times as well. I am attaching an audio file where I was able to capture the sound while under the bus. The audio captures the response to pressing the auto-level button (exhaust noises...pffft pffft pffft) followed by pressing the Travel Mode button which produces the whine/squeal. Where the rig is right now, it is really pretty level, so it doesn't take much exhaust to lower to the level position. The return to ride height is relatively quick, but the sound is repeated each and every time the air returns to inflate the front to ride height. There are 2 cycles of the Auto Level followed by Travel Mode actions captured in the audio file. I have listened and listened and listened and felt parts for vibration and cannot isolate anything vibrating or clearly responsible for the sound. Any suggestions or pointers for where the restriction to flow may be found, or where to look to stop the noise? Apologies for the long post, but I'm trying to be thorough and precise and not forget anything. I am hoping perhaps someone else in the hive-mind has encountered this or similar before. Valid Mfg responded that they were responsible only for the electronics of leveling and the manifold itself, and could offer no assistance, adding that it didn't sound like it was air moving through the manifold itself producing the sound. John (Audio) 2022-10-29 13.53.02 (2).mp3 Link to comment Share on other sites More sharing options...
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