Hi all,

I have a 2000 S500 with 149,000 miles. I have replaced all 4 shocks and the block about 2-3 years ago. Now, I think the pump is going bad.

When I come out to the car in the morning, the whole car sits really low. It will take a 2-5 minutes for the car to rise after I start it. The car runs normal all day, and then the next morning same thing.

Could this be a leak in the pump? I've replaced everything else and wanted to make sure it's the pump before having to replace that also.

Thanks for all your help.

 

how do you know you have ABC and not airmatic? Those are two different systems.

The ABC cars have a button that says ABC

Whether ABC or airmatic, you could have a leak in a line, so a pump wont help

 

I think you might have more than one problem.
Taking 2-5 minutes for the car to rise might point to the pump.
Bad pumps can produce lower than normal pressure.

But the suspension dropping could be more likely due to leaks in the valve bodies.
When the car is parked the pump and reservoir are essentially at zero pressure.
But there is still pressure on the other side of the valve bodies which must leak lack into the zero pressure (when parked) side of the system in order for the car to drop.

I would try a flush, with new filter & fluid.
Be sure to do the rodeo to dislodge debris or contaminants in the system so the filter can trap them.
Doing the rodeo will tell you something about the condition of the pump as you can monitor the pressure during the procedure.

I like to do the rodeo before as well as after the flush & filter change, but especially in a case like this.
Because if you do the rodeo and the dynamic tests first and find the pump is weak, you might avoid buying that criminally expensive petrosin fluid twice..

Did the two symptoms (slow rise and dropping) begin at about the same time?

Yee-Ha Ride 'em cowboy!