Sticky Water Pump Pulley?

Status
Not open for further replies.
SeacretSailor

SeacretSailor

.
Aug 27, 2006
126
C&C 29 MK-1 Mandeville (Lake Pontchartrain), LA
The last 2 times I've cranked up my Yanmar diesel, I heard a low screeching sound and found that the water pump pulley was not spinning in spite of the crankshaft pulley and water pump belt spinning. It was a quick fix, I easily (and very carefully) started the WP pulley spinning by giving it a qucik twist on the outside face (for safety) and it spun OK.

I have a Yanmar 2QM15 and I was wondering if anyone has seen this before? Maybe my belt's too loose? On the adjusting brackets, the WP is set as far back as possible, so i can't tighten the belt, or maybe I need to take it apart and check the inside.

Any thoughts?

Thanks!
 
Tim R.

Tim R.

.
May 27, 2004
3,626
Caliber 40 Long Range Cruiser Portland, Maine
That is your fresh WP beginning to fail. There is no repair other than replacement and it will fail catastrophically when you need it most.

A WP should spin very freely when the bearings are ok. When the bearings start to go they make noise and keep the pulley from spinning.

I keep a spare WP and gasket on my boat because this failure will ruin a vacation.
 
Last edited:
Ron20324

Ron20324

.
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
If the adjusment slot is at the end of it's travel, and the belt is too loose, DUH, I think that's a good signal to buy a belt a little smaller.:doh: If that works, get a second one of that size.
 
Last edited:
Hermit Scott

Hermit Scott

.
Sep 25, 2008
2,288
C30 Event Horizon Port Aransas
If you rebuild it now, you can do it for $20 or $30 +whatever your impeller costs. If you wait and the shaft gets scored, then it becomes better to buy a whole new pump.
There are a few bearings and a few seals to replace. Be careful removing the shaft, it is VERY soft stainless steel. The shaft will be over $100. Pressing it out would be best, but you may be able to tap it out, but be sure to thread nuts onto the shaft first so you won't mushroom out the shaft. I was amazed at how soft the steel is that yanmar used on my water pump.
 
Bill Roosa

Bill Roosa

.
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Raw or engine coolant pump

I'm not sure which pump you are talking about. The engine coolant pump should spin freely with the belt off. The raw water should have a significant amount of drag from bending the rubber impeller parts. Could be a loose belt. Check to see if the pully can be spun by hand with the engine off. If so it is certianly too loose. Could be the impeller is going on the raw water pump which only requires a change out.
 
Warren Milberg

Warren Milberg

.
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
Some things to check: how much "play" is there when you squeeze the water pump belt together? Shouldn't be more than a half inch or so. If more, you may the wrong size belt or one that has somehow stretched. Also, what is the condition of all your pulleys? Yanmar pulleys can and do deteriorate and need replacement. I also agree that if all else is well, you may want to consider replacing the pump's seals and bearings which are much cheaper than a new pump. Get the parts from Torresen or a Yanmar dealer.
 
Status
Not open for further replies.

Top Bottom