I've been living with my 99 XJ8 with the heater hoses bypassed together to get heat for about a year now...

So my water valve is defective, I think (pump is OK)..... Before I plop down $400 for a new one I would like to understand basically how it is supposed to work and if it is repairable (considering the cost for a used/new one).

There is a metal stem in the valve that the solenoid sits on top of. The solenoid "fires" fine but the metal stem move VERY little.... I can barely, I mean barley move it (about 1/32" I would guess) ....

How is this supposed to work? How much is that metal stem running through the valve supposed to move? Any insight to how it works?

Thanks for any help or insight !!!!!