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Sherwood Raw Water Pump
Posted: Sun Apr 12, 2015 8:10 am
by barkleydave
Ahh Spring has spring... engines roaring to life and darn....drip drip drip!!!
Fired off engines no problem. Starboard engine the Sherwood GH-7 raw water pump dripping. Figured must need a little snugging up.. Wrong!
I then noticed salad bowl was not filling up. Water was pumping but just running through the strainer. Pump needs rebuilding or replacement. Not sure strainer is not full. I did not disturb it but must be pulling air from somewhere. Get pump right first then move on. Pump is original 4 1987.
Major Kit was 2/3 cost of new pump. So looks like a new pump is in order. Never have had much luck rebuilding one of these. Expensive and short term fix has been my experience.
Oh well that's boating!
safe at the dock
dave
Re: Sherwood Raw Water Pump
Posted: Sun Apr 12, 2015 10:29 am
by Roger2
I would replace gasket on strainer first, suspect an air leak, that's why 1/2 full.
Roger
Re: Sherwood Raw Water Pump
Posted: Sun Apr 12, 2015 2:52 pm
by jralbert
Heed Roger before springing for new pump. But if sealing the strainer isn't the answer I may have your model pump, new, in the garage. Let us know.
Re: Sherwood Raw Water Pump
Posted: Sun Apr 12, 2015 8:09 pm
by Rockit
I had something like that happen. I put a new pump in and a new gasket for the strainer. I even tried switching strainers. No luck. I then took off each piece one at a time and found a crack in the intake line that was hidden by the hose clamp. All that time and money when all it needed was a piece of hose.
Re: Sherwood Raw Water Pump
Posted: Mon Apr 13, 2015 9:44 am
by Harryb
Hi if you have water dripping from pump itself and not just leaking from the hoses or clamps the internal seal is shot and the bearings will fail shortly, a rebuild or replacement will be required.

Re: Sherwood Raw Water Pump
Posted: Mon Apr 13, 2015 4:21 pm
by barkleydave
Pump was leaking. Tore down.. time was not good to her.
Was leaking around shaft got to bearings and pulling air around shaft causing cavitation.
Mr. Port I am sure is not going to be much better after 28 years and no rebuilds.
I noticed increased bubbles in strainer at spring start up. Been down that road before. Then I found the leak replaced impeller and it did not improve.
Re: Sherwood Raw Water Pump
Posted: Wed Sep 02, 2015 7:57 pm
by Trowerpower
So both of my circulating pumps (twins) are leaking a little water. So the seal must be replaced or the entire pump. So it's money and time ahead to replace the pump on each engine. Is that correct? The raw water pump brings the water to the engine. So every three years the impeller gets replaced. Any comments please .......
Re: Sherwood Raw Water Pump
Posted: Wed Sep 02, 2015 8:14 pm
by barkleydave
Almost as much to rebuild.
Impellers at least every other season.
I went three and had an Impellers missing pieces.
Quality not as good as older ones.
Dave
Re: Sherwood Raw Water Pump
Posted: Thu Sep 03, 2015 11:11 am
by Harryb
Both of my raw water pumps are jabsco pumps and very expensive to replace. I bought bearings, impeller and ceramic seal and case "O" ring, basically a rebuild kit from a company called Pumpco in St. Petersburg Fl. The seal itself is around 40 bucks and is the toughest part of the rebuild, it has to be pressed carefully into the case. The rebuild on the starboard leaked again after a few months and finally traced back to the stainless steel shaft being out of limits. The shaft was about 100 bucks from the same company, both working good now.

Re: Sherwood Raw Water Pump
Posted: Thu Sep 03, 2015 2:50 pm
by MetalHead
http://www.depcopump.com
Call these guys. They do complete or basic rebuilds at a good price.