My driver's seat keeps sinking down

Yes; my driver's seat definitely drops while I am driving.

 

I wonder if lester's post #17 here contradicts what fishonron wrote in post #7?

Lester says that the air in my seat should not be affected by the air in the rest of my truck. fishonron says that any leak anywhere on the truck can cause my seat to sink down due to an air leak. How do I reconcile these two statements?

Is it possible that both lester and fishonron are correct?

lester you said that the air in my seat should not be affected by the air in the rest of my truck. Is it possible that the air in my driver's seat could be affected by air in the rest of my truck because of a defect in the seat or a defect somewhere else on the truck?

 

Update: the mechanic told me that they could not find a leak, but the seat is still sinking. The mechanic thinks the problem must be the seat valve. He is ordering a new seat valve.

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The mechanic said that the seat did not sink when he drove it. But the mechanic is a lot taller than i am. I drive with the seat a lot higher than he does. Maybe that affects why it sinks for me but not when he is in the seat.

 

The mechanic checked that and could not find a leak. He thinks it must be the seat valve.