tntcrock wrote:
Yes it's a 643150
I tried to find a parts breakdown but I couldn't, but by looking at a it I think it's the same setup as my Monarch pump. When you look at the pump where the hoses are on both sides you will find a large hex fitting, remove them and you will see a screen and ball check mounted in the hex nut. The ball check is what stops the fluid from flowing back to the tank and all it takes is a small piece of dirt and the slide will creep. I cleaned mine by using hot water and soap, the ball is easy to depress for cleaning. I just shake it in the water rinse and let dry. You will also find a spool valve with a spring on each end, just put it back in the way it came out, because of the way yours is mounted it should stay in the pump.
Denny