If you can really help, but let's talk :-)My Mercedes is a 1964 300 SE Coupe, with air suspension.The 4 rubers air bags are new, and in a very good shape.But ...the car doesn't keep air very long : few hours after, the car is on the ground ....And when I start it, it takes 3 minutes to "take off" and reach its normal position. So I guess it must be the air valves, that allow to keep air into the rubbers bag, that may be the culprit. Could you help with this ?....Thank you for whatever you'll do for me .