Water Circulating Pump Replacement

[Fun2Ride]

After changing the fuel filter, starting the engine and checking the engine compartment for leaks I heard a funny noise coming from the circulating pump. Also the pulley was wobbling a little bit and I knew that shouldn't be happening. I turned off the engine and moved the water circulating pump pully by hand and it certainly did have a wobble.

Called the local marina and got a replacement water pump. I have a sea ray sundancer 270 1994 with a 7.4 liter engine. The old pump came off surprisingly easy. Only 4 bolts hold the water pump on. Two hose clamps hold the water pump onto hoses also. You do not have to have the boat out of the water to do this job. I had the boat in the water and when I pulled the pump, only the water in the engine spilled into the bilge which was about 1/2 gallon.

The new pump from mercruiser comes with two gaskets which I have installed today. Tomorrow I shall get new belts and finish the install.

The old pump was toast. When I pulled on the impeller, it actually wobbled and the seal was starting to give way. It was a matter of time before I would have been stranded on the open water. Keep on putting points into the black box (keep up on the maintenance) and you and your family will be safe. We are going to go on a trip on the 4th of July so I am glad we discovered the circulating pump problem.

I shall finish this thread tomorrow after I get new belts on the boat and I start it up for a test run.

Happy Boating!

 

[Fun2Ride]

Finished the water circulating pump install with new belts today. Started up the engine and let it get warm to 140 degrees and there was not one leak, belt squeal or odd noise. It was good to see everything working fine as it should. Total for the repair was $300. The breakdown is follows...

Mercruiser water pump $200
New v-belts 3 total $100
just in time repair $priceless

Tomorrow is the 4th of July and I will have peace of mind going out on the water!

 

[Skuza]

Glad you did a great DIY job. Now just make sure that if the impellor was bad that pieces of the blades aren't stuck in any of the coolers downstream. You can find this out by looking at the old impellor. If blades are missing remove hoses and try to fish out the pieces. Try to get as many pieces as possible and try to "rebuild" the impellor to guarantee you found all the pieces.
Good job!

 

[Dave S]

Skuza............I believe it was his engine recirculating pump that failed not his sea water pump. The recirculating pump does not have rubber vanes.

Dave

 

[Fun2Ride]

Skuza, thanks for the compliments! I replaced the rubber impeller on the sea water pump last year. The pump I replaced yesterday was the cast iron water circulating pump on the top front of the engine on over the timing cover. This pump lasts a long time and was the original from 1994. Man, you had me thinking and almost dumpster diving for the old recirculating pump (he he)!

 

[RichG]

Hi - I was hoping someone could provide more explanation on the difference between the raw water pump and recirculating water pump. I have a separate thread on an overheat problem - and thought (incorrectly it seems) that the raw water pump brings water into the engine where it circulates through and discharges. It sounds like the water cycle requires two pumps?

 

[tbirdvet]

yes two pumps. The raw water pump provides sea water to the engine water pump that circulates it through the engine and exhaust for cooling. The larger engines (e.g. 496Mag) has a closed cooling system but still needs sea water for the heat exchanger and exhaust cooling.

 

[penguin]

To make the best analogy I can to a car engine...

Raw water pump on boat = radiator fan on car.

Circulating pump on boat = water pump on car. This pump's only responsibility in life is to circulate water through the engine block.