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flattop · 03-05-2012, 04:53 PM

When dumping the air only the front is dropping. Thought I would check the rear dump valves. Anyone know where they are located on a 95 Dynasty? Also does a solenoid control the valves? Are the front air bags and rear air bags seperate systems? Thanks.

Papa_Jim · 03-05-2012, 05:19 PM

Quote:

Originally Posted by flattop

When dumping the air only the front is dropping. Thought I would check the rear dump valves. Anyone know where they are located on a 95 Dynasty? Also does a solenoid control the valves? Are the front air bags and rear air bags seperate systems? Thanks.

The air dump valves are known as MAC valves. They are an electric solenoid type valve. When you press the air dump switch on the dash, it activates the electric solenoids in the MAC valves, which causes them to open and dump the air from the air bags.

You have one MAC valve up front to control the one front air ride valve. Open your generator door, look straight ahead, then up a bit, then right a bit, and you should see it. It should be blue in color, and look something like a 2" cube. There should be two electric wires going into it, a couple of small air lines hooked to it, and an open brass fitting screwed into the bottom of it. The brass fitting may or may not have a short piece of rubber hose attached to it. When you have someone press the dash air switch, you will find air blowing out of the brass fitting on the front MAC air valve.

For the rear, there are two MAC air valves to control the two rear ride height valves. Open the engine compartment door. On most, the Mac valves are located just inside the engine compartment door on the right hand side. On some, they are located on the left hand side. Now that you have identified the appearance of the front MAC valve, you should be able to identify the rear MAC valves.

Check to see if the brass fittings are plugged, not allowing air out. Check the electrical power. I believe power is required to activate the air release. You could run a test power line to the MAC to test it. If they are not plugged, and there is good power to them, then possibly the MAC valve solenoids are seized, which would require replacement.

Hope this helps rather than confuse.

flattop · 03-05-2012, 06:05 PM

Thanks Jim, great explanation. I have owned the coach for five years and replaced two air bags, but just started having the air dump problem. After reading your reply, I will also check for mud daubers when I find the valves. They are a big problem here in Florida. Will also print this for my records.

sc3283 · 03-05-2012, 10:01 PM

My 96 Dynasty has the rear valves located where Jim has stated

Papa_Jim · 03-06-2012, 07:31 AM

Quote:

Originally Posted by flattop

Thanks Jim, great explanation. I have owned the coach for five years and replaced two air bags, but just started having the air dump problem. After reading your reply, I will also check for mud daubers when I find the valves. They are a big problem here in Florida. Will also print this for my records.

I have often wondered about air bags regarding deterioration of rubber, how long they last, when they should be replaced.

Did you experience an air bag failure? Do you have brand and part#? Do you recall how much they cost?

flattop · 03-06-2012, 08:43 AM

Jim, I did not have on the road failure on either bag. They had a small pin hole in each one that caused a leak down over a few days. The two bags I replaced have been front bags. So that is the only number I have. Found both leaks looking for other leaks with a spray bottle. They were weathered looking with cracks on the surface and small flakes of rubber missing in spots. I replaced one 4 years and the other one this past year. Easy one was driver side front of wheel. Hard one, passenger side behind wheel. Had to cut hole in the propane compartment wall to get to the bolts, then patch the hole. The first one was $112, last one $129. Welcome to Stengel Bros. Inc. - Steering, Suspension, and Air Ride Specialists

The number is 2B9-206. I got them here, but you may find them cheaper elsewhere.

flattop · 03-06-2012, 04:48 PM

Got the rear dump valves working. Had the wife work the dump switch and nothing. Tapped on them with a screwdriver handle while she kept working the switch and they started clicking. Must have been stuck as Jim thought. Sprayed some WD40 in the exhaust port kept working them, and they seem to be working fine. Thanks to all.

Papa_Jim · 03-07-2012, 08:32 AM

Quote:

Originally Posted by flattop

Got the rear dump valves working. Had the wife work the dump switch and nothing. Tapped on them with a screwdriver handle while she kept working the switch and they started clicking. Must have been stuck as Jim thought. Sprayed some WD40 in the exhaust port kept working them, and they seem to be working fine. Thanks to all.

Good news! Probably the solenoids were a little dry and sticking. As long as the electric solenoids are working, the rest of the valve is serviceable. Inside are a few generic little o-rings. Often, the MAC valve can be taken apart, cleaned and lubed, reassembled (often with the original o-rings), and they're back to like new again. The only thing that would require replacement is if the electric solenoid stops working.

Thanks for the air bag source info. I've filed it away for future reference.

walt2137 · 03-07-2012, 06:15 PM

Quote:

Originally Posted by flattop

Got the rear dump valves working. Had the wife work the dump switch and nothing. Tapped on them with a screwdriver handle while she kept working the switch and they started clicking. Must have been stuck as Jim thought. Sprayed some WD40 in the exhaust port kept working them, and they seem to be working fine. Thanks to all.

If you can get to the inlet air line remove it and spray a little teflon spray in the line and valve and reinstall the line this should lube the O rings without swelling them. Jim is right they are a easy rebuild and should be able to get the O rings from any auto part store.