Leaking air

[markmiiler]

The pressure relief valve on the haldex dryer keeps sticking open. Is this a common problem as this is the second time to happen. Last time we had to replace the dryer unit.

[barmcd]

You need to service your dryer. You'll need the upper and lower kits to get the parts to service the relief valve. If you do it yourself, it's a lot easier and only a little more expensive to just buy a new dryer. You can usually find them for about $275 and the two kits run a little over $200. Then it's just a swap.


https://www.amazon.com/Haldex-Midlan.../dp/B00480MQTG


https://www.amazon.com/Haldex-Midlan...5FEM32D7JBK0DG

[FIRE UP]

Originally Posted by markmiiler

The pressure relief valve on the haldex dryer keeps sticking open. Is this a common problem as this is the second time to happen. Last time we had to replace the dryer unit.

If it is in fact, the pressure relief valve, shown in one of the links, then simply replace it. If it's the relief valve, there's no need to rebuild or service the air dryer. Now, if you choose to replace it, you may need to either remove the air dryer or at the very least, loosen the mounting bolts so you can gain access to that relief valve. Some are installed in such a way on the dryer that they cannot be removed unless the air dryer is removed or loosened enough to do the job. You can get those pressure relief valves at many hardware stores, some auto supply stores, Graingers, McMaster Carr, Air compressor supplies stores and more.
Scott

Here's even an Amazon link for one.

https://www.amazon.com/Compressor-Sa...ef+valve&psc=1

[barmcd]

While FIRE UP is correct, you can just replace the valve, there is good reason to do a complete air dryer service while you are under there. The air dryer removes moisture from your air supply and should be serviced every three years according to Haldex. Most RVers don't do that and the moisture removed from the air supply gunks up the coalescing filter in the bottom of the dryer. When that happens the gunk interferes with the operation of the relief valve and it leaks. If you wait too long to service the air dryer, it can spread descant throughout the air system and that can end up locking the brakes in the on position and then you can't move the coach.

Here's another thread with some interesting reading.

http://www.irv2.com/forums/f258/hald...cy-241539.html

[Bigd9]

Originally Posted by markmiiler

The pressure relief valve on the haldex dryer keeps sticking open. Is this a common problem as this is the second time to happen. Last time we had to replace the dryer unit.

The answer is no. There is something wrong with your system. Get it checked out by a competent technician. It may not be the air dryer at all, but maybe the air pressure regulator on the air compressor or other contaminants in the air system causing the valve to "stick open". If you are on a Freightliner Chassis, I would suggest heading to Gaffney and let Freightliner look at it.

[Jake21]

You didn’t say that when you replaced the dryer, you replaced the valve.