Catalina 350 International Association

Raw water pump on Westerbeke showing has a leak and price being quoted for replacement Sherman pump is $832. Ouch. Any insight from others on replacing this part much appreciated.

Fred,

I replaced my raw water pump with this from CatalinaDirect.com

From my order...

Items Ordered
-----------------
Water Pump, 1/2" Oberdorfer, Repl for 1/2" Sherwood (#Z3936): 1
Item Total: $466.40

Water Pump Adapter Elbow, 5/8" x 1/2" NPT (#Z3955): 1
Item Total: $15.91

====================

Subtotal: $482.31
Shipping (Best Way): $12.95
Total: $495.26

Bill
C350, #193
Atlanta (Home) / Charleston, SC (Boat)

Fred, you can also just replace the pump seals. Provided the shaft isn't scored, new lip seals should fix and water leakage problem. Here's a pretty good writeup on bearing replacement on a Johnson pump which is similar to the Sherwood. https://marinehowto.com/rebuilding-a-raw-water-pump/

The option that Bill chose is also a very good one. The Orberdorfer pump has the advantage of a forward facing face plate so access to the impeller is much easier since you can actually see what you are doing rather than working blind.

Thanks Gents. Good info to consider. Can't quite understand the Sherwood design with access tucked behind the pump.

Hi All. quick question. My Sherwood raw water pump maintained the water temp at EXACTLY 163 degrees F for years. However, since I have "updated" to the Orberdorfer, the op temp is now around 170-175. Does anyone else have any data on this swap?

thanks

dave B

Dave,

Prior to my swap, mine sat at 160. After the swap, it still sits at 160.

Double check with the manual, but I think they quote 170 as the normal operating temp for the M35B engine.

I’m assuming you don’t have any air pockets and that your exhaust splash looks ok.

Also, on the Catalina Direct website, I think they mention some folks have a temperature rise after installing.

Bill

I noticed a similar slight change (increase) when I changed from Sherwood to Oberdorfer. I don't know exactly how much, the temp gauge always sat just to the right of the straight up at 160 degree position so maybe 162-165. Changed to Oberdorfer and it moved slightly to the right maybe closer to 170 but that is a guestimate based on the straight up position being 160 and the next marking to the right is at 180.

The Sherwood is a slightly bigger impeller with more vanes, so it is expected to perform slightly better. But its negligible.

OBTW I just flushed and changed the coolant last year and that did move the needle again slightly, back towards nearer the 160 mark, so maybe down a few degrees, now sits at maybe 163-165. by my estimation.

Not a problem at all to see a slight change with the Oberdorfer.