New rear bags : zero lift

[bkahler]

Its safe to say I did something wrong but I'm not sure what

Yesterday I replaced the right side rear air bag on our 1984 310 MH. I struggled using a jack and jack stands to get enough room to do the job. After removing the jack stands the air bag system still worked.

So today I tackled the left side rear air bag. Only this time I used the leveling jacks to raise the back end up and then put jack stands in place for safety purposes. Removing the left side rear air bag went a lot faster, but then again I knew what I was looking for. Had the old one out and the new one in place in about half the time compared to the first one.

Anyway, after lowering back down onto the ground I filled the air tank and nothing else happened

The system is holding 105 psi no problems (ok, its actually leaking down REAL slow but almost not noticeable) but NO air is getting to the bags. I have to assume I screwed up the leveling valve some how. Unfortunately the way the MH is sitting right now I can't get a good look at it. From what I can see though nothing looks bent or misaligned. But then again I'm not really sure what I'm looking at.

Anyone have any photos of the valve that would show some detail? Also any information on how to adjust it would be a big help.

The maddening part is I was supposed to take the MH for new tires and alignment on Friday. If I can't get the bags to fill there won't be any new tires.

Worst of all is in 2 weeks we're planning our first trip in the MH and if I don't get this working and a bunch of other necessary tasks then we can't take the MH

Any help would be greatly appreciated.

Brad

[guy99]

Brad,
I just sent you an email with a zip file of some manual pages, hopefully they'll help.

[bkahler]

Originally Posted by guy99

Brad,
I just sent you an email with a zip file of some manual pages, hopefully they'll help.

Guy,

Thanks for the tech pages. Unfortunately adjustment turned out to not be the problem. I also tried MH87's (Dennis) suggestion to drive it around the block a few times to no avail. So after trying the driving and then the adjustment steps I ended up pulling the valve out and found that air was not coming out of either of the raise or lower ports. So I took the two air fittings out and noticed that there was an orifice of some kind on the inlet side. So I unscrewed the orifice and tried cleaning it. After putting things back together the bags started filling with air. Unfortunately the discharge port was also dumping air.

The only conclusion I can come to is the valve is bad. I checked with a local truck suspension place in Little Rock and they said they might be able to match it up with something in stock. So I'm on my way to Little Rock after work tomorrow.

I'm keeping my fingers crossed.

I'll post pictures tomorrow of the old valve and hopefully the new valve with part numbers.

Thanks for the suggestions.

Brad

[Robfike]

One of the valves failed on my 345. I took it to a truck spring place here in Indy, and they replaced the valve. It is a normal "truck" item.
Rob

[Inland RV Center, In]

Originally Posted by bkahler

Its safe to say I did something wrong but I'm not sure what

Yesterday I replaced the right side rear air bag on our 1984 310 MH. I struggled using a jack and jack stands to get enough room to do the job. After removing the jack stands the air bag system still worked.

So today I tackled the left side rear air bag. Only this time I used the leveling jacks to raise the back end up and then put jack stands in place for safety purposes. Removing the left side rear air bag went a lot faster, but then again I knew what I was looking for. Had the old one out and the new one in place in about half the time compared to the first one.

Anyway, after lowering back down onto the ground I filled the air tank and nothing else happened

The system is holding 105 psi no problems (ok, its actually leaking down REAL slow but almost not noticeable) but NO air is getting to the bags. I have to assume I screwed up the leveling valve some how. Unfortunately the way the MH is sitting right now I can't get a good look at it. From what I can see though nothing looks bent or misaligned. But then again I'm not really sure what I'm looking at.

Anyone have any photos of the valve that would show some detail? Also any information on how to adjust it would be a big help.

The maddening part is I was supposed to take the MH for new tires and alignment on Friday. If I can't get the bags to fill there won't be any new tires.

Worst of all is in 2 weeks we're planning our first trip in the MH and if I don't get this working and a bunch of other necessary tasks then we can't take the MH

Any help would be greatly appreciated.

Brad

If no air is getting to the system, then check the "in line" check valve.

They have a habit of sticking closed, which will not allow the air to reach the valves.

Andy

[bkahler]

Thanks for all the replies. Here is an update.

I went to Little Rock Spring & Clutch supply (thanks for the suggestion Robfike) and bought a new replacement valve. Total cost was $70 including taxes. Part number was Haldex 90054007. Common part for trucks.

Took all of about 30 minutes to get the new valve installed. At this point the MH was still on jackstands. I turned the MH on and let the compressor start pumping up the tank. Tank reached full pressure and the bags didn't do anything which is pretty much what I was expecting since the arm was parallel to the ground at that point. I then removed the jack stands and lowered the MH to the ground and the bags started filling Once they reached full pressure I measured the height and it came out to 10-1/4" which is what the service manual for the 310 states should be plus/minus 1/8" or so.

I then went and had dinner and came back and found that the air pressure in the tank had dropped from 100 psi down to about 65 psi. So I guess I have a leak. I'm hoping its the check valve as I have one on order from Inlandrv that should be here this week. Next morning when I went out the MH air bags were deflated completely. So I guess I have a leak somewhere there as well. I'm wondering if it might not be the old air lines

Today after having driven it to the tire place and then the alignment shop I parked it and left it for about 4 hours or so. The air bags were still inflated but the tank pressure was way down. I then went inside the motorhome and walked to the back and all of a sudden I could feel the MH start dropping in the rear. I guess my added weight meant the valve called for more air and since there was not enough in the tank the MH settled lower.

However there was definitely a marked improvement in ride with the new air bags

Tomorrow we're ording Bilstein shocks all round and a new Bilstein steering damper. If I can get the air leak solved we should be in great shape with the suspension.

Pictures to follow tomorrow.

Thanks for all the help,

Brad

PS, don't believe the gas gauge. Just because it reads slightly above empty it may not be. Don't ask how I know this......

[Alumatube]

Originally Posted by bkahler

PS, don't believe the gas gauge. Just because it reads slightly above empty it may not be. Don't ask how I know this......

Or why we have a shiny new 5-gallon gas can...

Susan

[Geophilist]

Brad,

Don't know about your 310, but my 280 has a schrader valve in the bottom of the air tank. I have found that crud builds up in that valve and it likes to leak. Put some soapy water on it and see if it bubbles. Mine would also backflow thru the compressor which had seen better days.

Good hunting,

Steve

[bkahler]

Originally Posted by Geophilist

Brad,

Don't know about your 310, but my 280 has a schrader valve in the bottom of the air tank. I have found that crud builds up in that valve and it likes to leak. Put some soapy water on it and see if it bubbles. Mine would also backflow thru the compressor which had seen better days.

Good hunting,

Steve

Steve, mine used to have a schrader valve. Some PO removed the valve portion and then stuck a 1/4" airline over it using a hose clamp to hold it in place. He then ran the airline over to the side by the electrical compartment door and put a schrader valve there for easier access. My guess is that was done because the air compressor didn't work and they needed easy access to put air into the system.

I still haven't found the leak, to many other things to worry about fixing. I did replace the rubber line and that didn't help. Given some time this week I'll use some soapy water to check out some of the fittings. I did install the new check valve from InlandRV and that didn't help so the leak has to be one of the line fittings.

Brad

[Robfike]

One thing I just remembered. When we got our 345, the rear bags would deflate after shutting off the coach. One problem I found was the plumbing in the area of the compressor. Someone had put it together wrong. There is a solenoid valve that releases the pressure between the check valve and compressor at the end of each compressor cycle. This is to lessen the pressure that the compressor must overcome at start up. Mine was plumbed so as to relieve the SYSTEM pressure at the end of each compressor cycle. You may want to check your plumbing against the book.
Rob