This new Geko pump started to lose vacuum once I stop squeezing as well, pretty short lived both these 2 new pumps I bought.bucket wrote: ↑Sun Aug 06, 2023 9:20 pm If you're brake bleed hand pump starts to lose vacuum once you stop squeezing the grip, it is most likely a dry valve inside. If you unscrew the front section (the cylinder behind the hose fitting) you'll see a thin flat black valve seal. Carefully lift the edges up with your fingers (nothing sharp) and gently pull it up until the "stalk" comes out of the hole behind the seal. Wipe down the flat brass surface and clean with a tissue the underside of the seal that would sit against the brass surface. Then get some Vaseline and put a very thin layer on the brass around the hole and reinsert the seal "stalk" back into the hole until the seal sits flat against the brass surface. Screw the front of the pump back on, ensuring the rubber ring is free of dirt, put some Vaseline on it before you do so to give a better seal. I've done this several times now, maybe once every 2-3 months. As long as you're gentle with the delicate seal you'll get many years out of the pump.
Tried this earlier and it works perfectly. Thanks a lot. I fixed the leluv hand pump too.
If it wasn't for your reply I might have been buying brake bleeders for a while. I wouldn't have figured it out by myself.