View Full Version : Raw Water Pump
08-28-2004, 04:09 PM
My raw water pump is making a screaching noise so I shut it down. I've discontected the intake hose and hose that continues on to the motor and I've taken the pump loose from the bracket. When I slowly turn it on the shaft that's still conected to the crank, it feels really crunchy as if a bearing is getting ready to fly apart (it also leaks). I assume I should just go ahead and replace the pump - skiDIM has 'em for $150 +/-....I've seen seals for them but this seams more than just a seal, crunch, crunch, crunch, grind.... :huh:
The good news is a took my starter and alternator in and had them rebuilt - elctrical problem solved :)
It's always something...
- while you're sleeping, things are breaking....
It definitely sounds like a bearing is or has gone south.
There are rebuild kits available for these pumps. Contact Jabsco(or Johnson) and see if the sell them and how much they cost. A press is needed to remove the shaft from the seals and bearings.
08-28-2004, 09:46 PM
I recently had my raw water pump rebuilt for much less than buying a new one. It was only $60 total. That included new bearings, seals, and impeller. :D
Must be something in the water. I think mine did the same thing last night. I'm about to go out and pull mine off (after my first cup of coffee) and check it. Nates where did you get yours rebuilt? Can any marine repair shop do it? Or even better yet, is it a DIY project with the proper kit?
OK, the "good" news is that the pump is fine, just the impeller needs replacing. When the impeller went the engine ('94 EFI, not LT1 with 450hrs) got hot- 220 deg. I pulled the plugs and checked for water in the cylinders - none, did a compression check - 175 - 180 psi. on all 8, and as it was time for an oil change, removed the oil. Now for the questions; 1) the oil, dino oil with approx. 50 hrs, is dark chocolate brown color, is this OK or is it considered "milky" and pos. have water in it? 2) I plan on replacing the impeller, plugs, oil and filter, is there anything else I should check prior to buttoning it up and running it? Thanks for the help.
How old was the impeller? If it was screetching, it was dry. If it's dry, I suspect the oil cooler was clogged and you need to check that a lot more often. The manual recommends checking it in the list for what to check before going out, every time.
JimN, checked the trans cooler and no debris.
08-30-2004, 09:07 AM
I think I got lazy and ordered a new pump from skiDIM...along with the screaching sound, the temp was running a little high (not pegged by any means) - my impeller was fine...I didn't check the trans.cooler for debris as JimN suggests...ooopppsss...but at least I'll have a good raw water pump when the new one arrives...
I assume the install is fairly straightforward - three allen bolts on the crank, drop the bracket, bolt the new one up and go have some fun... :dance:
oh yeah, check and clean debris from trans.cooler... :D
08-30-2004, 09:11 AM
When your impeller went, were you able to identify where the broken-off impeller vains went? Sometimes they can clog something "downstream" ....
No I was not, but, fortunately I caught the problem early. The impeller only had five vanes with semi-circular, M&M size pieces gone. I am hoping that these were small enough to run completely through the engine.
If you look at the vanes where the rubber is missing, it coincides with the slots in the housing and this is caused by wear from not either being changed soon enough or the abrasion from sand, silt and other stuff.