old Sanso P-100 problem

hi
i am trying to activate an old well pump of the brand Sanso P 100. After som dealings, it pumps, but the pressure switch doesn't work. I don't really understand how it is supposed to work. If anyone knows the model, there is this gadget with a membrane, connected to the part closest to the intake through a thin pipe, with a valve-like thing under a screwed lid (sorry for my vagueness) - this seems to me to be some kind of mechanical pressure device . what is it?? i have tried to tamper with it with no results

on the other hand there is an obvious electric switch, that won't be moved by pressure building up inside the tank

well, does this mean anything to anyone, what can be done

all the best,
anders erkeus, sweden

How about a picture? I have never heard of that brand name and a pic is worth a thousand words.

bob...

no camera connection

hi,
thanks , good idea, however, i can't connect my camera to the laptop i am using here in the countryside.

by now i have disassembled most of the pump, and i am slowly coming to the conclusion that it is just a lack of pressure that cannot be compensated by the little regulation screw in the pressure switch. the thing delivers about half the amount of water per minute that it promises. I have eliminated the major visible leakages, but there are obviouslu more, or can the actual mecanism be worn?
anders

What kind of mechanism is it Anders? Does it have an impeller, which is a round disk attached to the motor shaft with spiral volutes and a center hole about 1-1/4" in it? Or is it a piston type pump with a piston, valves and a cup leather on the piston. Or possibly some other kind of pump?

bob...