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.