Skip to main content ↑ ↓
Topic: Haldex pop-off (Read 572 times) previous topic - next topic

Haldex pop-off

I noticed, after leaving the CG this morning that my air pressure was a little lower (90 psi) than its usual of around 115- 120. I rationalized that I had just left before it was at full pressure. Sure enough, about 10 miles down a narrow 2 lane Texas road in the middle of nowhere (Coleman), my air pressure went south real quick. Got over and was able to stop with about 25 psi left on the gauges.
I was able to track it down to the dryer's pop off, it was steady blowing out. I called Kieth at MOT and asked if I could remove the pop off and plug it. He advised, "as long as the pressure is not too high, it should be good to go and to get a re-build kit (which includes the pop off) when I get home". It took longer to get the unit loose enough to get the socket on the pop off to change it. Ran back to town and got a brass plug for this fix. I was back on the road in about two hours.
I am still developing my Foretravel 6th sense and will hopefully pay more attention to things that change or just don't sound right.
 Lot's of RVs in this Fort Stockton WM, at least a dozen or so MHs. Will be in BB tomorrow! Can you say drag race in the morning, lol.
Rick & Deborah Webster
2002 3610 U320 #5964
2014 Jeep Wrangler Sahara JKU- 'Copperhead'
Richland Chambers Lake, East Texas
 

Re: Haldex pop-off

Reply #1 –
Air dryer has a brass pressure release valve screwed sideways into the bottom which usually never opens. And a built-in pop-off valve that opens with every pressure cycling, releasing downwards. Sounds like your pressure release valve got stuck open.

Even though the filter kit has the valve, most techs do not replace the brass valve when changing the two filters on normal maintenance. Usually the pop-off sticks open when there is a problem, which is fixed with a bottom repair kit or a whole rebuilt dryer.

How long has it been since changing filters? Since the valve is an emergency release, it can temporarily replaced with a plug. Everyone has a difficult time removing the pressure release valve because of the tight clearances. Some have ground down a box wrench so it will fit.