Rear Leveling Air Pump Not Working

[Huet]

I have a 2007 GX 470 that I use to tow a boat ~3500 lbs. Typically, when I attach the boat to the trailer hitch, the rear end of my GX 470 will lower ~1.5", then the air pump will activate and bring the rear end back up to a nearly level position. Lately, the pump has quit working. I've taken it to my dealership, they've checked it out and told me that the system is working fine. When I brought it home and attached the boat, the air pump is still not working. I've got an appointment on Monday to haul the boat up to the Lexus dealer and show them the problem. I can raise the the rear end using the switch on the dash, and the pump works.

Has anyone else experienced a similar problem, and if so, what was the fix? I'm thinking that, although the "system" is working fine, somewhere there has to be a sensor or switch that tells the system to work - that isn't working.

[TexGX]

I had my airbags pop off after I lifted my GX. I decided that I did not want the cost of new air bags so I had coils installed an love them.

TexGX

[mann777]

Check you Height Control Solenoid has moisture intrusion, then they die slowly, time for replacement.. The pump will work, but not the height control. Expensive part, but still do a bit of troubleshooting then conclude I would from a good Auto elect.