Working on a friend's Catalina 34.We rebuilt water pump .. he bought the parts. Torreson sold him the Globe Marine blue run-dry model 815 for the Oberdorfer on his Universal M 25 XP.. I noted that the pump case has some wear in it and that the blue impeller is slightly smaller in diameter and slightly less wide than the old black one that came out. The blue vanes on the side away from the eccentric are touching so lightly that they aren't bent backwards. Pump is now intermittant. We can get it to pump by removing the discharge hose and gunning the engine until it begins to pump then putting the hose back on. It will then pump until it is shut down for a few hours.. Yesterday we motored a couple of hours after priming, with no problems. then the hose off thing has to be done to get it to pump again. I believe that the impeller is too small to seal as it should.. We did check to be sure the vanes were not turning on the hub.. Anyone have similar experience or observations?? Going to get a black impeller now to replace the blue..
EDIT: I read some entries concerning the blue impellers and I know that the boat has the larger heat exchanger (3"). Flow once primed seems ok and the thermostat is controlling the temperature at about 170 F .. I did not expect to be able to stop flow with my thumb over the discharge , but was able to. Pressure seemed to be around 5 psi, but that is just a guess. I would have thought more pressure.. ??
EDIT: I read some entries concerning the blue impellers and I know that the boat has the larger heat exchanger (3"). Flow once primed seems ok and the thermostat is controlling the temperature at about 170 F .. I did not expect to be able to stop flow with my thumb over the discharge , but was able to. Pressure seemed to be around 5 psi, but that is just a guess. I would have thought more pressure.. ??
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