What can be wrong with this part spring inside is ok, but gums outside i dont know What is the name of that part?
For the 3-point unit to function as designed, each of the rubber O-rings must form a gas-tight seal. If it seems that the O-rings are original, they are likely to be hard and inflexible, so replace them. I don't know what the correct sizes are, you may have to experiment. I don't remember having much trouble finding some that worked when I refurbished my 2e2. Good luck.
