New water pump already weeping after 30 hrs

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Roland Gendreau

Roland Gendreau
1992 MK 1.5
Gratitude #1183
Bristol, RI

Joyride

All,

THank you for the responses.  I brought the new pump in to the shop (reputable in St. Petersburg FL) they pressure tested the new sherwood and couldn't get it to leak so they are saying that I might have a restriction in the flow.  My strainer looks good and I did pull some zinc out of the hx which would inhibit but I don't think much.  Would there be anywhere else where I'd be getting water flow issues besides the hx?  The hx exit hose is new (replaced due to cracking last year but didn't see much if any build up.)

would the waterlift potentially have build up or does anyone have a suggestion?  Even if I go to the Ob pump I would still like to understand this better.
1991 Catalina 34 (mk 1.5) Universal M35 Wing Keel

Craig Illman

You might check the raw water injection fitting into the exhaust. There could be some buildup there. Also, when you had the starboard endcap off the HX, were the hose fittings clear as well? I was surprised to find one of mine over 50% obstructed by salt precipitation last fall.

Craig

Stu Jackson

#18
Quote from: Craig Illman on February 03, 2017, 12:18:46 PM
You might check the raw water injection fitting into the exhaust. There could be some buildup there. Also, when you had the starboard endcap off the HX, were the hose fittings clear as well? I was surprised to find one of mine over 50% obstructed by salt precipitation last fall.



Craig's right.  The inlet port where the cooler salt water hits the hot water in the HX is notorious for salt buildup.  I've been commenting on this for years, ever since I removed our old HX in 1998.  Do a search on "Mariachi" :D  Sorry, I just did, so it must have been in one of my older tech notes, when I removed my 2 inch HX and cleaned it out, also found what Craig described.  I shook it and it sounded like a mariachi band!  :clap

But you really have to do a SYSTEMATIC analysis, rather than asking "where else to look?"  The H2O comes in through the thru hull and goes out through the exhaust at the transom.  Check everywhere in between.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

KWKloeber

So that begs the question -- what pressure did they run on it? 
Hopefully equal to or higher then it can put out.  And if there was no leak past a seal, then even if there was a TOTAL obstruction, say in the Hx, the pump **won't** leak. 

I'd remove and/or in-place test the flow thru the Hx to see if it has an obstruction or significant pressure drop.

kk

Quote from: Joyride on February 03, 2017, 11:17:31 AM
All,

THank you for the responses.  I brought the new pump in to the shop (reputable in St. Petersburg FL) they pressure tested the new sherwood and couldn't get it to leak so they are saying that I might have a restriction in the flow.  My strainer looks good and I did pull some zinc out of the hx which would inhibit but I don't think much.  Would there be anywhere else where I'd be getting water flow issues besides the hx?  The hx exit hose is new (replaced due to cracking last year but didn't see much if any build up.)

would the waterlift potentially have build up or does anyone have a suggestion?  Even if I go to the Ob pump I would still like to understand this better.
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain