"91 park avenue air shocks on rear axle

[abe]

When I seat 6 adults in my '91 park avenue ultra, the rear of the car almost bottoms out. When I cross over a railroad track, or hit a small pothole, the rear of the car does bottom out. I installed new air shocks a couple of years ago, and they are in good shape and don't leak air. I know there's an air pump in the engine compartment, but what triggers the pump to switch on and keep the rear from sagging when there's a load?
abe

[parkavepartsman]

You are correct, there is an air pump under the hood. It is on the driver side. There is an "arm" on the rear axle, it's been a while but as i recall it is on the passenger side, there is a small rod that comes straight down off a plastic arm, and clips onto the lower control arm. This is how it knows where the suspension is. I have never seen any problems with the actual control mechanism.

First thing to do, check the fuse! Don't quote me, but i think it's fuse #12 - 20 amp. your fuse panel cover should tell you. If the fuse is good, pop the hood and make sure that the air compressor is plugged in. I have seen quite a few that are unplugged! Now that you know it is plugged in and the fuse is not blown, go under the rear of the car. Bring a small flathead screwdriver with you: on the bottom of the pass lower control arm there is a rod attached with a plastic ball/clip thing. pop the little clip open and pry the plastic keeper off the metal ball that is on the lower control arm. move the arm all the way up, this will tell the system that the suspension is all the way down and needs to adjust. it should come on after a couple-15 seconds. if it does not, perhaps turn the key on (it shouldn't need this but you never know), if the compressor starts to run (it is fairly quiet but you'll be able to hear it) but the struts don't pump up, you either have a leak or a blockage in the line.

The most common problem i have seen in these cars is a kinked line! I believe it happens during assembly! Go under the car, near the gas tank i think. Find where the air line comes out of the interior and comes outside under the car. it is a small (1/8" or so) whiteish clear plastic line. They are almost always kinked right where they come out of the car and wrap around some wires. unkink that, sometimes you need to cut the line and splice in a new one. you should be able to get some push on connectors at home depot. they should also have the plastic line... if not you can order it online, although i don't recall where i ordered mine from.

sometimes the line will wear through from rubbing on something and start to leak.

another thing to check for, is if you had a blockage or a leak, the compressor may have burnt itself out from trying to pump up the suspension but not being able to! I have seen the connecting rod inside of that compressor broken right off! i have also seen the motors quit working. So, i guess go as far as you can with the info i just gave you. After you do that, let me know if you need some more help. email me direct at fordsucksme@yahoo.com

-eric

[abe]

partsman
you hit the nail on the head. It was a blown fuse. When I put the new fuse in, the pump kicked on, and to my surprise I could hear air hissing from the drivers side air shock. The rubber was leaking badly---there's a gaping hole on the blind side that I couldn't see, but you sure can hear it--and feel it-- when the pump kicked on. That explains the blown fuse. Called Azone, where I bought them (Gabriels), and luckily they are under a lifetime warranty.
abe