Yanmar 4JH3E. Where to find the Sea Water Pump Impeller fin debris?

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truscott

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On a whim I decided to replace my Sea Water Pump Impeller. I can't be certain that I didn't pull the fins off myself when I started pulling the impeller out, but I'm pretty certain that some of them were missing anyway. So, assuming that the debris has traveled out of the sea water pump, where should I start looking to make sure all is clean?

Also, has anyone got a good schematic as the one in my manual doesn't seem to match what I'm seeing.

Many thank in advance.

Cheers, PT
 
Thanks for the link. I did eventually find the schematic in the manual that I have. Sadly, I did not find any debris in the end cap, so the heat exchanger is going to have to come out. :(

When does the cruising start? So far my life aboard is washing, shopping for groceries and fixing things that I didn't even realize were broken!


coopec said:
Maybe you could follow the schematic in your manual if you had a quick look at this article

Marine Closed "Freshwater" Cooling Systems
http://www.cpperformance.com/t-marine-closed-cooling-systems.aspx

View attachment 57244
Click to expand...
 
truscott said:
Thanks for the link. I did eventually find the schematic in the manual that I have. Sadly, I did not find any debris in the end cap, so the heat exchanger is going to have to come out. :(
Click to expand...

If a couple of vanes are in there it might not cause that much problem unless your cooling was already marginal. What does the flow out through the exhaust look like and does the flow only get slightly warm at high revs rather than hot?

Having said that, I personally would prefer to get the bits out if I could so would try backflushing from the exhaust elbow feed through to the hose connection on the front end of the H/E. Hopefully you can get access to a good water tap with decent water pressure. Have a helper with a bucket handy and plenty of old towels and give it a go. You've nothing to lose! :)

Richard
 
truscott said:
Thanks for the link. I did eventually find the schematic in the manual that I have. Sadly, I did not find any debris in the end cap, so the heat exchanger is going to have to come out. :(

When does the cruising start? So far my life aboard is washing, shopping for groceries and fixing things that I didn't even realize were broken!
Click to expand...

After you get everything fixed-you start cruising. Then,you continue to repair things as you cruise. :o

I added another RW filter after my RW pump to catch bits from hoses & impellers,since my HX is 1/2 days work to remove,clean & re-install. I went with an inexpensive plastic one similar to: http://www.westmarine.com/buy/shurflo--raw-water-strainers--P011_332_001_503

Suggest you inspect/install a new impeller annually & keep spare(s) on board. You may wish to consider a Speedseal kit also.
http://www.speedseal.com/SpeedsealLife/SpeedsealLife.html

Best of luck! / Len
 
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Have dismantled the Heat Exchanger only to find it is clear. So I guess they're either in the exhaust or have passed through the exhaust. So glad I begun this process (although the state of the old impeller means I will chalk it up as a win).

Waterflow has been fine. I just had that niggling feeling and decided to replace it "just because". The boat has had Guardinage for a few years, and I had engaged them to service the engine and replace the impeller. Looking at the old one, it would appear that this didn't happen. :(

Like the idea of a RW filter after the pump.

I am moving to the newer Yanmar impeller's that have a thread in the part that goes on to the pump axle to take their "impeller puller". Getting the cover off was easy enough, but getting the old one out was a PITA. Hopefully the new setup will make it easier to remove and replace annually. Time will tell.

Thanks again for the feedback.

Cheers, PT
 
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