01 s430 Airmatic pump. I have my car at the shop because the car is in the full up position and will not come down to the normal positing (light on dash is off). The shop has informed methat it is a check valve in the pump that is stuck. They are telling me I have to replace the pump not just the valve???

My question is can the valve inside the pump be replaced or are they correct by telling me I need to spend $750 to replace pump?

Help

 

Hi,

It looks like I missed your post so didn't offer an opinion.
However i notice that you now have a pump for sale!
Is the problem fixed. Why the pump for sale?

I'm not sure but I suspect that what you have been told re the pressure relief valve being part of the rump assembly may be correct although the sensor is a straight screw in. Its all about keeping the complexity of parts stocking down.

However the diagnosis doesn't appear correct to me. Why would the vehicle go to "Wade" height if the pump output pressure was too high. Yes it would set a code and you would get a warning. In addition although possible failure of the pressure valve is extremely unlikely. Its usually the pump motor or one way carbon valve in the cylinder head that gives trouble at high mileage / or failure due to constant running (caused by a leak in the system).

I suspect that you had a height sensor issue. The height sensors are little potentiometers fitted to the struts to sense ride height. These are very vulnerable to damage / corrosion / water. Relatively low cost items.

Alternatively I would be looking for a fault on the "Wade" height switch after first resetting the Airmatic suspension ECU. Power down etc. to ensure that the ECU had not "crashed".

Usual failure mode of Airmatic is Too Low>

Stuart.