Need help with suspension all height sensors look good or not broke or popped off. Air compressor comes on but doesn't lift up but Air compressor sounds like air is being pushed back out the way it comes from. Any ideas?

 

Are you saying compressor sounds like it is straining?

 

I think I am having the same problem. My compressor comes on, pumps air, however I believe the air solenoids are not clicking on. I checked all fuses, at least I think I have and non are blown. Does the air compressor relay control the signal to the solenoids?

 

I’m going to be checking it shortly

 

I have an 04 Navigator that in the past blew out the passenger front airbag (ripped open). After playing with many rebuilds I finally got the Suncore unit with the aluminum top as that turned out to be leaking, possibly before the bag blew out. I recently had a front driver airbag leak and I replaced it with the same Suncore complete unit. Now it would not lift as it seems air was leaking at the compressor to air drier (compressor overheated due to the airbag leak and melted the o-ring connection at the drier?) so I replaced the entire compressor/dryer assembly. It then lifted again and so I left it overnight. The next morning it's all the way down again and now it won't lift at all. The compressor runs, but the air solenoids are not opening. I even took the old solenoid off the blown bag and put it back in and still nothing. I checked fuse #20 and it looked good, I even replaced it just to be sure. I have put a jack under the front and rear and manipulated the vehicle's height sensors as this has worked in the past, but nothing this time.

Hoping someone comes up with some suggestions on what to look at next.

 

Pull a line off the compressor. Put a finger on the outlet. You should not be able to hold the air in. My second one was weak and I replaced it. New one lifted the truck in less than 5 minutes.

 

Not sure which of us you are replying to. I pulled the line out of the drier and attached it to my air compressor. Started the Navigator and the pump comes on, but still no lift. Air solenoids are still not opening.

 

I know you can open the solenoids with a 9v battery, so that will be my next test. Open a solenoid when the pump is running and see if the bag inflates and lifts. I will trick the system by plugging in a spare solenoid so it will not error out.

 

Didn’t know you had bypassed the compressor. This is same thing my 98 dud when compressor got week

 

I tried to use my 9v battery and air compressor and I could not get the air solenoid to open. I tried with my spare solenoid in my hand and it opened and air flowed though it. So I replaced the solenoid that came and was in the Suncore front airbag with the solenoid from the original airbag and tried the 9v battery again, and I was able to put about 20 psi in the front bag. I had the wheel off and a jack under the front frame. I put the front wheel back on and dropped the front and it dropped all the way down. 20 psi was not enough. But now that I replaced the front air solenoid I hoped that was the problem so I started the Navigator up and the pump cam on. It took 3 tires and the rear of the Navigator lifted, but not the front. The pump is still cycling 2x but the front is still all the way down.

The next step is to see if I can attach a pressure gauge to one of the lines and see how much pressure the pump is creating.