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porourke · 12-09-2010, 12:07 AM

We have a 1993 LY MH 33 Footer, Can any one tell us the location of the air leveling valves on the rear air suspension. I want to check and see if we have air leakage out the exhaust ports on either of them

Porourke -

f4fixer · 12-13-2010, 12:57 AM

We have a 91 classic not a LY and i just happen to have a picture of the valve. That shock in the pic is for the road side of the tag axle. The valve is right behind the tag mount.
hope that helps

Don

gloran · 12-18-2010, 09:46 PM

I was wondering if you found the leveling valves? I looked for them on my 1993 and couldn't find them, and came to the conclusion this was a change on this model, because they weren't where they were suppose to be according to owners manuel. But I might be wrong and just didn't look hard enough.

porourke · 12-19-2010, 07:00 PM

Yes, on ours they are located about half way between the air accumilator tank and the rear wheels. One for the left side and one for the right side, but odly enough the input lines are teed together, looks like one would have been enough. I have never sent a Picture in a post but here goes. It will make it a lot easier to find with a picture - it was for me.

porourke · 12-19-2010, 07:09 PM

I forgot to add - it looks like this clean - the falve in the MH will be filthy.
The two fittings are the air in from the accumulator and air out to the bag. The long black tube is the exhaust tube. The Actuating lever is in the back with the nylon support on it. Thats where the linkage hooks to to activate the valve when the Coach heigth chanes. I got them from anythingtruck.com - Very Very reasonable.

Good luck

gloran · 12-23-2010, 07:02 PM

Porourke. I found one of the leveling valves, didn't see one on the curb side. Also this is going to sound stupid, but the air supply tank they show in the manuel C4 page I can't locate either. Where is that located on your coach?

gloran · 12-23-2010, 08:09 PM

Also went to anythingtrucks.com. Is this the correct product code #270E9623? Were they very difficult to replace, and were you going to replace the inline check valves? If so, did you find a replacement part number for them? Thanks for the info. Randy

Inland RV Center, In · 12-23-2010, 08:23 PM

Seldom will a leveling valve leak, however, very often the check valve does not prevent a back flow of air, to the compressor, where the bleed down happens.

Adding another check valve in the air supply line, or replacing the original check valve, is basically about a 99 percent fix.

Andy

porourke · 12-24-2010, 03:08 PM

The other leveling valve is located directly accross from the one you found. You have to get up on one elbo to see it. The airtank is located in the engine service compartment just to the right of the radiator. The air pump is at the top up hi and the 2 or 3 gallon air tank is just below it right next to the power steering pump reservoir. It is a long black container with an input and output line coming out the bottom, Also on the bottom there is a petcock hand operated valve to drain off moisture, looks just like the drain valve on a radiator. There is also suppose to be a Schrader tire valve to fill the tank manually if the pump goes out but I never could find it

gloran · 12-27-2010, 07:03 PM

Even though both our coaches are 1993's, from your description yours appear to be quite different from mine. After searching extensively I am positive! I have only one leveling valve. Also the airtank that is located under the hood, is about 6" around and 10" long in size, holding two to three quarts max. Its mounted sideways with the air lines coming out of the center on the end, and there is no way to drain moisture, no drain valve of any kind or tire valve to add air. Must have been a model change sometime during that year, also with my service manual being outdated for my year coach,its not much help with alot of this kind of information. I think the two rear air bags are tied together so maybe only one leveling valve needed.

porourke · 12-27-2010, 09:08 PM

Its a shame they did not put a 5 or 6 gallon tank on these things. A larger air tank would mean that the compressor would not have to cycle on and off so much while you are in motion, that would save wear on it. The only down side to it is from a empty tank it would take longer to get it up to the 140# that the pump cuts off. On the leveling valves, that is the correct part#. If you change them your self BE VERY CAREFUL when you adjust the linkage, hers why. Although the pump will put out 140# I am not sure that the air bags would handle that. Looking at the pipeing diagram in our book, I think that as the coach rises and starts closing the valves, when it gets to level and the valves are closed all the way you dont have the full 140# in the bags - My guess is 80 to 100#. The drawing also shows 2 leveling valves one on each side but teed into both air valved, which to me is overkill. As far as the check valve goes it only shows one in the output line to stop air excaping back through the pump when it shuts off. This can be a leak sourse but its easy to check, we did, but you have to have full pressure on one side to check it. They were not hard to change and adjust. Just make sure you use teflon tape to seal the threads on the line fittings but not so much that some of it breaks off and gets hung up in the orings or pumatic delay part of the valve.

TTFN

porourke · 12-28-2010, 12:11 AM

This is a scan from the OP manual that came with our coach. Its accurate only thing is no component location-

I wouldn't change it unless you are shur its leaking. Leakage will ether come out around the input shaft or the vent tube with the valve closed all the way.

Pat

Smartstream · 12-28-2010, 01:48 AM

Quote:

Originally Posted by porourke

This is a scan from the OP manual that came with our coach. Its accurate only thing is no component location-

I wouldn't change it unless you are shur its leaking. Leakage will ether come out around the input shaft or the vent tube with the valve closed all the way.

Pat

The system shown doesn't make a lot of sense to me. With the two bags connected by the "T" with the line going to the air pressure sender there is no reason for two leveling valves. If the bags were not connected they could level the coach not only up and down but also side to side. The "T" connection loses the side to side leveling ability and eliminates the need of a second leveling valve.

My 28' classic is set up like the diagram except that it uses a single leveling valve. The valve by the way has a delay of several seconds so that air is not added or discharged every time the actuator arm is moved going over a bump or pothole. The coach body must be raised or lowered and remain so for a few seconds before the air system will react to return the coach to the correct height.

Cheers, Dan

porourke · 12-28-2010, 05:28 PM

Yes I agree, the only reason I can think of is if you develoupe a bad leak and the pump cant keep up both bags will deflate at the same time. But this would work with only one valve. The built in delay in the valves makes it time comsuming to adjust the linkage that works them. I had decided that if I couldent get the leakage problem fixed I was going to break both fill lines loose from the leveling valves, cap one off and take the other one and lengthen it and put a Schrader bulk head type fitting inside one of the curb side storage cubby holes and fill them manually. You would also have to cap off the output ports on the leveling valves if you wanted to keep the Air Horns and quick change connection working to toot your horn and fill your tires. OR if not just pull the fuse on the air pump! Nice thing about doing it this way is that the Dash Air guage sender would still read air pressure in both bags. I think the same thing would apply to a coach with one leveling valve. I may do this yet. If there is any one that reades this post that has changed over to a manual fill type setup, please post about. I need to know if leaving them filled all the time would cause any problem in the bags them selves.

TTFN - Pat

masseyfarm · 12-28-2010, 05:44 PM

I think you are trying to complicate the system more than needed.
The air bag system is used on 90% of the highway trucks and many trailers, and parts are available everywhere and reasonably priced at any truck shop.
If you want a larger air tank, that could be installed.

Are these bags the suspension, or are they just the assist to springs? I only have some air suspension experience, not air assist.
There are two level valves on most applications to compensate if you ran the drive axle up on a curb or ridge. Otherwise you would loose traction, AND BREAKING. Many front solid axle applications have just one level valve.

Air leaks will show up with soap water spray, and hoses leak where excess heat gets to them or if they are rubbing on something. If that is not found, take the line off forward of the check valve when the bags are inflated, and again check with soap.
If you can't locate the check valve, it may be buried with addons, just install another as Andy suggests.

Dave

Smartstream · 12-28-2010, 06:57 PM

The air bags don't care if they are filled from a bulkhead fitting or on-board pump. They also have no problem being full all the time. The front bags on the P-30 are bulkhead filled, full all the time and they are used as spring assist. Part of the function of the rear bags is to maintain ride height with varying loads. The number of passengers and their baggage as well as fluid levels in the tanks all affect ride height and the leveling valves take care of the problem.

You can remove the valves and alter the system but it is a very simple and dependable system and making it function properly is neither difficult or expensive. You have a very nice luxury coach why do something that would make it less than that?

Cheers, Dan

Mike Leary · 12-28-2010, 07:32 PM

I wonder if most of the older Classics still have the 60-40 switch for the compressor/bag inflation? I had so much trouble with my bags that my local Fire Dept. suggested a Seattle company that ripped the whole system end to end. Works perfect.

Smartstream · 12-28-2010, 07:41 PM

Quote:

Originally Posted by Mike Leary

I wonder if most of the older Classics still have the 60-40 switch for the compressor/bag inflation?

I give up Mike, what is this 60-40 switch?

Mike Leary · 12-28-2010, 07:49 PM

Quote:

Originally Posted by Smartstream

I give up Mike, what is this 60-40 switch?

It's the same kind of switch used in well water pumping systems, when the pressure falls to a certain level, the pump (or in this case the air compressor) kicked on and shut down when it reached it's max setting. Mine is now solid state without the points of the older switch system. In our coach, it was located in the same rear roadside compartment as the shore power cord and transfer switch box.

Smartstream · 12-28-2010, 08:06 PM

Quote:

Originally Posted by Mike Leary

It's the same kind of switch used in well water pumping systems, when the pressure falls to a certain level, the pump (or in this case the air compressor) kicked on and shut down when it reached it's max setting. Mine is now solid state without the points of the older switch system. In our coach, it was located in the same rear roadside compartment as the shore power cord and transfer switch box.

I think you made that up, my books just call it an air compressor pressure switch, with or without an unloader valve. Water pump switches are similar but are water proof.

To your original question I still have the original mechanical type switch in my Moho and if my memory serves me I think Hans and Lili have the original in the Vinnie-mobile in the UK.

Cheers, Dan