The old iron bicycle pump can't breathe when it touches the motorcycle valve, and the air pressure will push the pump up. How can we improve this pump?

As mentioned on the first floor, the old drum has a one-way check valve at the bottom of the drum, which is specially used to prevent the air in the tire from flowing back. As you said, the check valve is broken or poorly sealed. It can be repaired by grinding the sealing surface or replacing the spring. What I want to say here is that a small spring does not necessarily have accessories. If it can't be reformed with some small springs or steel wires, the elasticity will not be too great as long as the check valve can be reset.