W50 - Greasing the Seawater Pump Impeller

redvette · **Joined:** 14 Dec 2006 22:13 **Posts:** 59

On my previous boat with an Atomic 4, there was a grease cup on the rear, starboard side that you filled with white, marine grease and then turned a half-revolution every so often to grease the impeller. By turning the cup, you were basically screwing it in, and thus forcing the grease thru a little hole and into the impeller housing.

I have noticed when removing the water pump on the W-50, that there is a small screw on the front of the pump that I believe my parts manual described as a grease port or grease screw. I'm assuming that this may work the same way as the A-4 grease cup, i.e., removing this screw, filling the hole with grease, and then screwing in the screw every so often. I see no other reason for this screw on the pump housing. Any thoughts? If this is true, is there any need to close the thru-hull to the sea water inlet first before removing that screw? Thanks.

Down2TheC · **Posted:** 20 Apr 2009 00:54

I doubt you'd get free flow at the pump. It's barely below the waterline and the vanes probably get in the way depending on where that port is.

Falco · **Joined:** 23 Dec 2007 23:08 **Posts:** 42

If I understand the screw location, there is a screw on the pump that holds/adjusts the flat rubber cam against which the impeller compresses, forcing the water out of the pump. It is not, per se, a lubrication point as you would be lubricating the back of the plate, never reaching the wear surface. There are many diagrams of the pump on-line. Look for Jabsco Model 5320-0011. It will be item #9 (the screw) pushing against item #5, the cam.

Should you need a copy of the parts list, repair instructions and pertinent drawings, e-mail me and I will send you the PDF. Note that this is the pump on my 1979 Westerbeke 50. There are, potentially, others that were used on earlier or later models. This pump is, however, used on many motors and the construction of others is quite the same. If you want to lubricate the impeller easily, put some white lithium grease into the intake side of the pump and start the motor (having reattached the inflow hose). Tartan

redvette · **Joined:** 14 Dec 2006 22:13 **Posts:** 59

Thanks guys. I thought the screw on the water pump looked too small to serve as a grease cup, so your explanation for it's use sounds right. I have both the parts manual and tech manual for the W50. I thought I looked thru the applicable sections but I'll check again. Anyway, I should check the impeller once each year anyway and could grease it then.

Tartan37.com

W50 - Greasing the Seawater Pump Impeller

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