Community Forums

wsmcycle · 03-28-2023, 04:02 PM

I have a 630 magna. The rear end goes down in about 20 minutes of engine shut off. It stays up going down the road. I have had the rear air components checked and they found a few very small leaks in a couple of solenoids which we replaced. They were not the culprit. If they had been, it would have been a day or more for the decent of the rear end. I am suspecting the air pressure that supports the rear end is being diverted to an air tank by the HWH, because the air pressure will hold about 120 over night but the rear drops anyway
Any ideas? I would appreciate. When we park-up, I have to lower the whole RV to to maintain a height. If I level with the HWH, it works but the rear will sink in just a bit and necessitate re-levelling. Also, there is no whooshing sound of air expelling as it sinks. Nothing like dumping the air to lower with the HWH.
I sold the Matisse and purchased this Magna two years ago. I need to update my signature.

2-Nickels · 03-29-2023, 05:38 AM

Your issue is puzzling. If I read your description correctly whether you just stop and park the MH or you level with the HWH the rear end drops after 20 minutes? If you have levelled with the HWH does the 12 volt compressor come on to try an re-level the coach? I can’t help but believe there is still a leak(s) which have not been found. If the air tanks are holding pressure over night then the air trouble is after them and I too don’t understand what is blocking the air from leaving the tanks. I would start at each of the rear air bags and soap every fitting on forward.

twinboat · 03-29-2023, 06:24 AM

A leak is the only reason for the rear to drop.

It's like a tire, you put air in and it stays unless it has a leak.

The ride height valves are what holds the air in the bags. Look for a leak from them to the bags.

wsmcycle · 03-29-2023, 09:53 AM

Thanks all
Seems the consensus is that there is a leak somewhere in the back. Let me add some information. My mechanic (very thorough guy) spent a lot of time spraying soap solution on all the components and only found two small leaks in solenoid valves ( which we replaced). Maybe I am wrong but a leak capable of lowering the rear end in 30 minutes would make a pretty big sound, and there is no audible sound now that the solenoids have been replaced. That is why I thought that the air was going back into a tank and the HWH was telling it to.
Perhaps I can find a diagram of the air circuit for the rear lift circuit?
I will report the finding and thanks again for the responses. I agree with them except for the lack of noise from the discharge of the air loss

twinboat · 03-29-2023, 10:10 AM

The air could be going back to the tanks if the tanks are lower in pressure the the air bags BUT that can only happen if the air is backfeeding thru the ride height valves.

If its leaking back, it would also be leaking forward when the tanks are full, causing your ride to top out above ride height.

If you leave it running, dies the rear of the RV keep moving up ?

wolfe10 · 03-29-2023, 10:13 AM

Please confirm that you have air leveling.

If so, could be a problem in your rear "6 pack".

wsmcycle · 03-29-2023, 10:38 AM

I do have air levelling, yes
While engine is running, the RV does not raise higher than travel mode. It can be over-raised by the levelling button on the HWH or the raise button.

deandec · 03-29-2023, 01:42 PM

On my old rig my front air leveling would bleed down in a couple of hours once the engine (and its air compressor) was turned off.

My air tank pressure gauge would also decrease.

My repair was replacing the air hose tank connection at the tank near the front axle. $0.60 cost with a spray of dawn & water.

Has your mechanic checked the fittings at the air tanks?

Both of mine are near the front axle.

wsmcycle · 03-30-2023, 08:56 AM

I think he has only checked the rear of the RV where the problem appears. I will suggest he check the air tanks in the front. Thanks for the suggestion!

wsmcycle · 03-30-2023, 10:38 AM

If the only thing holding air in the back is the bladders, it would not take long to leak down. I think I was wrong thinking it would be a big leak. Those four bladders would not hold nearly as much a tire at 100psi.

MECMagna · 04-04-2023, 02:05 PM

I am working through the same issue with my Magna 630. I was not able to find any leaks using soapy water but I knew there had to be a leak somewhere. I ordered an ultrasonic leak detector from Amazon and quickly identified two leaking solenoids on the tag axle manifold above the transmission. Olstroms ordered new solenoids and I plan on having all of them on that manifold replaced since it is so difficult to access. He also suggested carefully checking the electronic valves for the air venting (switch in the cabinet behind the driver's seat) located below the coach behind the front steps as these valves are also prone for failure (mine are okay). I was impressed with the ultrasonic detector as it was quick, easy to use, and cleaner than spraying soapy water under the coach to look for a leak.

DJ55 · 04-04-2023, 04:42 PM

Quote:

Originally Posted by MECMagna

I ordered an ultrasonic leak detector from Amazon...I was impressed with the ultrasonic detector as it was quick, easy to use, and cleaner than spraying soapy water under the coach to look for a leak.

That detector sounds interesting. Can you provide a link to the one you purchased?

MECMagna · 04-05-2023, 07:23 AM

Inficon Whisper Ultrasonic Leak Detector. The headphones that come with the unit are low quality so I used higher quality plug-in earphones which worked very well. They made small hard to detect leaks sound like a jet engine!

wsmcycle · 04-10-2023, 09:17 AM

How about selling it to me for half price and I return it to you so you have only half in it. my veracity is only the fact that i am a fellow 630magna owner of good rapport on this forum. My mechanic has sprayed soap water till he is tired of it. I would first check with him to find if he would be willing to try this method.
How is this different than a simple stethoscope? i have one of those for isolating machine noises.