I'm having an issue with a Hill Mk4 Hand Pump. I disassembled the pump and lubed all of the O-rings for maintenance purposes after about 4 months of light use. I just did it again after another 4 months of light use. The pump worked great for a few days and was very smooth to pump. I am now having an issue where the pump wants to spring back down as I am pulling the handle up. Also, it seems like a small amount of air is pumped on one down stroke, and then a much larger amount of air is pumped on the next stroke, and this cycle repeats. I typically only pump up to about 180 bar. Does anyone have any ideas on how to resolve this issue?
Thanks!
Thanks!