Air dryer pressure valve blew, looking for advice.

Topic: Air dryer pressure valve blew, looking for advice. (Read 1640 times) previous topic - next topic

Air dryer pressure valve blew, looking for advice.

April 26, 2019, 11:36:14 pm

Luckily it happened at the rv site. The pressure valve n1178GB started leaking and I lost all the air, I put in a plug and was able to build pressure to move the 5 feet I needed to move. Now the fix. Air dryer is a da33100x. Can't get one until Monday or Tuesday at best. I was able to pick up a da34100 which Haldex tech support recommended as an upgrade. Took everything apart, it won't fit without redrilling holes in the steel plate. So here are my options.

1. Wait for a da33100x and replace it. Sacramento says they have one due Monday.
2. Use the n1178gb valve out of the da34100 (it's the same). Haldex tech recommends against it, said don't spend any time with the old dryer.
3. Create an EDB, and bypass. I'm 500 miles from home, 8 hours. Don't know what not having an air dryer that long would cause.
4. Bypass and take the coach somewhere to have th da34100 fabricated in. (I'm in Cloverdale Ca.)

Ok folks, I'm all ears.

Re: Air dryer pressure valve blew, looking for advice.

Reply #1 – April 26, 2019, 11:36:52 pm

A pic for r reference.

Re: Air dryer pressure valve blew, looking for advice.

Reply #2 – April 26, 2019, 11:42:24 pm

I vote for Option #1.

Re: Air dryer pressure valve blew, looking for advice.

Reply #3 – April 26, 2019, 11:52:59 pm

IF (big if) all your hoses will connect (without modification) to the new "upgrade" da34100 dryer, then I think I would use the new dryer. You could hook the dryer up to the hoses so it is operational, and then jury-rig some way to hold the dryer in place long enough to get home. Use some small cargo straps, rope, bailing wire - whatever will tie it down so it doesn't fall out going down the road.

Then, when you are back on home turf, get the mounting plate drilled for a proper installation.

Just my armchair opinion, of course.

Re: Air dryer pressure valve blew, looking for advice.

Reply #4 – April 26, 2019, 11:53:29 pm

Search air dryer bypass, unless your subject to freezing temperatures.

Re: Air dryer pressure valve blew, looking for advice.

Reply #5 – April 26, 2019, 11:54:39 pm

Bypass it run home and fix at your leisure. It's not going to kill your air system.

Re: Air dryer pressure valve blew, looking for advice.

Reply #6 – April 27, 2019, 12:43:09 am

Chuck, I already verified all the fittings and hoses will work, I like your idea, how vertical does it need to be?

Re: Air dryer pressure valve blew, looking for advice.

Reply #7 – April 27, 2019, 04:00:47 am

Do reply 3 and use big zip ties,think it could be somewhat less then 100% vertical.

Re: Air dryer pressure valve blew, looking for advice.

Reply #8 – April 27, 2019, 07:08:44 am

You can run forever with the air dryer bypassed.

Re: Air dryer pressure valve blew, looking for advice.

Reply #9 – April 27, 2019, 07:10:22 am

With that pressure valve opening you need to check your governor cut out point. If your governor has failed it can cause the compressor to continue to build pressure resulting in this relief valve to open. Did you notice a higher than normal air pressure on your dash gages just prior to this failure? If the governor has failed you may have the same results with a replacement dryer or the safety valve on your "wet tank" can/will open if it's set point is exceeded.

Mike

Re: Air dryer pressure valve blew, looking for advice.

Reply #10 – April 27, 2019, 08:34:11 am

Quote from: Rodaboss – April 27, 2019, 12:43:09 am

Chuck, I already verified all the fittings and hoses will work, I like your idea, how vertical does it need to be?

I am guessing it is not extremely critical. Just do the best you can to make it vertical. Did the new dryer come with any mounting instructions?

I found the document below - see the last line at bottom of page, left hand column:

https://www.haldex.com/globalassets/north-america/documents/air-dryers-_-air-line/l20466.pdf

Re: Air dryer pressure valve blew, looking for advice.

Reply #11 – April 27, 2019, 08:48:37 am

Quote from: Pamela & Mike – April 27, 2019, 07:10:22 am

With that pressure valve opening you need to check your governor cut out point.

I agree with Mike - however you get your coach back on the road, pay close attention to your dash air gauges on initial startup. You have still not determined what caused the relief valve on your old dryer to fail. According to the link below, the N1178GB dryer safety valve is rated at 235 psi opening pressure. This is well above the opening pressure for the OEM safety valve fitted to Foretravel wet tanks. They are usually set at 150 psi. Your wet tank relief valve appearantly did not open. So a bit of a mystery there...

https://www.anythingtruck.com/product/070-N1178GB.html

Re: Air dryer pressure valve blew, looking for advice.

Reply #12 – April 27, 2019, 09:15:12 am

Option #2............use the N1178GB valve until you get home where you can mount the new DA34100 properly.

OP said valve was leaking, not open?

Re: Air dryer pressure valve blew, looking for advice.

Reply #13 – April 27, 2019, 09:32:09 am

I was looking at the spec sheets for your "old" and "new" dryers. The "new" dryer has two stages of safety valve protection: primary at 175 psi, and secondary at 235 psi. The spec sheet for your "old" dryer does not list the safety valve rating (or ratings, if there are two valves).

IF the "old" dryer also had two safety valves with similar ratings, then that would indicate the primary safety valve did not open. I think this would be another good reason to NOT try to use the "old" dryer to get home.

DA33100X - Air Dryer - Haldex product

DA34100 - Air Dryer - Haldex product

Re: Air dryer pressure valve blew, looking for advice.

Reply #14 – April 27, 2019, 09:43:21 am

Quote from: Travelin' Man – April 27, 2019, 09:15:12 am

OP said valve was leaking, not open?

What causes a safety relief valve to leak? Does it slowly unscrew itself until it leaks around the threads?

Far as I know, a safety relief valve only "leaks" when it opens (either fully or partially), relieves the excess pressure, then fails to close completely.

If my thinking is correct (no guaranty there), why did it open?

Re: Air dryer pressure valve blew, looking for advice.

Reply #15 – April 27, 2019, 09:49:02 am

I only repeated what the OP said. I have not seen it personally that I can provide an answer.

Re: Air dryer pressure valve blew, looking for advice.

Reply #16 – April 27, 2019, 09:53:04 am

Totally agree - would be very nice to have more details concerning the original "failure" event. Don't want to jump to (false) conclusions!

Re: Air dryer pressure valve blew, looking for advice.

Reply #17 – April 27, 2019, 10:03:38 am

However I did miss the thread title that says it blew. Having a second cup of coffee now and wiping the sleep outta my eyes.

Re: Air dryer pressure valve blew, looking for advice.

Reply #18 – April 27, 2019, 10:07:30 am

I have often read that parts "Just Fail"

Age, quality control, bad molds used in production, inferior material.... Or LIFE just happened.. I have also learned that Bad things happen to good ppl all the time..

Sometimes its not worth the investigation... sometimes it is.. as they say YMMV..

Re: Air dryer pressure valve blew, looking for advice.

Reply #19 – April 27, 2019, 10:17:38 am

I've had my oatmeal, and I'm waiting on my coffee. I hope you've had a hearty breakfast.

You wrote:
>Haldex tech recommends against it, said don't spend any time with the old dryer.

I agree.

Again you wrote
>Create an EDB, and bypass. I'm 500 miles from home, 8 hours. Don't know what not having an air dryer that long would cause.

Not having an air dryer will cause the moisture to settle out in your tanks. So drain your tanks when you get home and replace your air dryer at your earliest possible convenience. Once upon a time, opening the drains on the air tanks was an end of day ritual.

Then again you have a good excuse for extending your stay. Just saying.

Re: Air dryer pressure valve blew, looking for advice.

Reply #20 – April 27, 2019, 10:35:47 am

I didn't see any rise in pressure. I believe the relief valve simply failed. After I lost the air, turned the engine back on, and the valve immediately leaks. Prior to the valve leaking, No other release of air from purge valve, which should be 150 or 175. That said, did the dryer somehow malfunction causing the relief valve to fail?, Maybe. I'm guessing it just got old and failed, that's why I'm not crazy about using the old dryer. I can blow through the valve. I'm going to build the EDB this morning, and have a couple of options. Can't overstate my appreciation for all your help. This is the #1 reason I bought a Foretravel.

Re: Air dryer pressure valve blew, looking for advice.

Reply #21 – April 27, 2019, 10:52:39 am

Don't know what, exactly, you need to do to mount the new dryer permanently in position. Any chance of getting the required holes drilled in the mount, either by yourself or somebody else? If you could do that, then the new dryer could be completely installed and you'd be done with it.

I carry a full complement of hand and power tools on our coach, but I know that's not the case with every owner. Someone at the place you are parked might be able to suggest a local handyman or shop that could help you out?

By the way, that DA34100 certainly looks like a good upgrade for your coach. I would definitely choose it over the DA33100X!

Re: Air dryer pressure valve blew, looking for advice.

Reply #22 – April 28, 2019, 11:57:56 pm

Ok, did the bypass, drove it home, check twice, and found very little water in wet tank. Now the permanent fix. Thanks all!

Re: Air dryer pressure valve blew, looking for advice.

Reply #23 – April 29, 2019, 02:16:44 pm

Drill the mount and use the new style , easy parts, easy filter change . all more better.

Re: Air dryer pressure valve blew, looking for advice.

Reply #24 – May 09, 2019, 09:33:49 am

Update. Add to have a bracket created to push the air dryer forward for clearance. Did a wood prototype and had my local metal shop draw it up and laser cut it, very reasonable. Fit like a glove, Now have an updated dryer.

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