Mt Silca SuperPista has been a great floor pump for the last 5 years, and I've been using the Shraeder chuck head to pump up my motorcycle and even truck tires.
But now it's as if a valve is stuck. The pump does not leak at all and it does still inflate tires, but if I take my hand off the pump handle, the tire pressure causes the handle to pop up. Also the pressure gauge goes briefly up to the (approximately correct) pressure, then the needle immediately drops.
I'm on my third leather gasket, and this happens with both the presta and Schraeder head, so I presume the problem lies in the pump body?
Any ideas?