Originally Posted by
Wilfred Laurier
If you re-read the OP's description of the problem, he was not able to get the air in the tube (pump rebounded after pushing air in) and suspected it was because of a faulty removable valve core letting the air back into the pump. My point was not that valves are not necessary on tubes, which is absurd, but that OP's problem was not one of a leaky valve or valve that fails to close, because that's not how pumps work. As I have said many times in this thread, pumps have a check valve, and air will not push back in to a properly functioning pump because the valve on the tube is faulty - there would be other problems caused by a malfunctioning valve, but OP's problem is not one of them.
That's not how I read the problem. The relevant quote:
It has become a rubber lung: pump air in, exhale air out, pump air in, exhale air out while your pump pressure gauge keeps returning to 0.
44.5mph doesn't describe the pump handle rebounding due to a faulty check valve in the pump. He also says it happened with a second pump
and that the problem went away with a different tube. Obviously, there is something wrong with the valve
in the tube. You have been concentrating on the pump.