Water Pump Leaking

[Leon]

I have a 1982 Catalina 27 with a 2004 rebuilt Atomic-4 inboard gas engine.I had the problem with my water pump few weeks ago. The water was not coming out.So I removed water pump impeller, found out that most rubber blades were broken. I slided impeller shaft out of pump housing and had the the broken impeller replaced. I reinstalled the cover plate with a new gasket. I restarted the engine and everything seems ok as I could see the cooling sea water coming out, but with white smoke (steam? or burned oil?). The engine temp seems ok as it was kept at 170C when the engine was idled.However, the engine temp was rapidly increased to above 200C when I tried to motor out the boat even within a very short time, but water was still coming out indicating the cooling water was running well (?).I checked the engine and saw a serious leaking at water pump as shown in the attached pic, but found no leaking around the cover plate. I was not able to "see" where is the leaking. I could "feel" the water dripping from the body of the water pump. Is there anyone who has knowledge about any possible location of the leaking? I once suspected the rusted grease cup? and how is the connection between the engine temp and the water leaking? And, what it could tell me with the white smoke coming out from the cooling water? Or, did I miss something when I reinstalled the water impeller?

 

[joe friedman]

ask the expert

your best bet is to get ahold of moyer marine (www.moyermarine.com). this is the place to go if you have any questions about the a-4.

 

[tim dranttel]

could be an old pump issue

some water pumps have a weep hole that will leak water when the shaft seal starts to deteriorate. Not an expert but I think it was designed that way to warn you that the pump needs replacing before the seal gives way completely and you contaminate the engine oil with sea water. In the beginning it will start leaking after the engine warms up. As the seal gets more and more worn the leaking gets worse to the point where it leaks whether the engine is hot or cold.Tim

 

[Ken Juul]

water pump

If it didn't leak before you changed the impeller, chances are that is what caused the problem. You said the all the blades were broken. Were you able to collect all the pieces? my guess is that you have a serious blockage of you water passages. The new impeller is doing it's job, to move water. It can't go through the engine, so it is leaking past the seal. Lack of water flow or air trapped in the engine will cause an overheat. Did you bleed the cooling system to remove all the air after you changed the impeller?

 

[Leon]

Comments from Don Moyer

You probably have two issues going on at the same time. The reason the engine is overheating is probably due to a piece of broken impeller blade getting stuck in one of the fittings within the cooling system. Good prospects include the 90 degree elbow on the discharge port of the pump, the diverter cap inside the "T" fitting in the center of the water jacket side plate or the fitting where the engine cooling water is introduced into the exhaust system. The diverter cap is particularly suspect, since a blockage in that area would account for your observation of normal flow of water out of the exhaust at the same time that the engine is overheating. Pieces of impeller blade can position themselves so that water will pass by quite normally at one time, and at other times they can flop over into a position that will block flow.In terms of the water leaking from the pump, I suggest that you get an inspection mirror at a local auto parts store so that you can see where the water is coming from. It seems clear that the water is coming from the pump, so there are only three logical places that it can leak: the seals, the gasket between the housing and the back plate or through a failed check valve in the grease cup assembly.Best regards,Don Moyer__________