Water pump rebuild after 11 years and 600 hours

[DeepCMark58A]

I will not argue with your result.

 

[Lou C]

can't go wrong following the FSM!

 

[flyingscott]

Did you not read the part about the temperature gauge ?

If the temp is proper and the pee stream is strong everything is good to go

What does the pee stream mean?

 

[Mc Tool]

What does the pee stream mean?

Cooling water indicator

 

[Jeff J]

I like the OP has a good way to monitor water pump health without disassembling the lower unit. Some manufacturers say to replace the impeller after so many hours/years, whichever happens first but some just say inspect and replace as needed after some many hours/years.

I am replacing parts if I go to the trouble of opening it up whether they need it that day or not.

 

[flyingscott]

Cooling water indicator

PEE stream means nothing. Only means that water got to that point. The only good pee streams are the ones plumbed in after the thermostat.

 

[Trudy9]

As the title states, I rebuilt the water pump on my 1998 115 2+2 this weekend. It had been 11 years and 600 running hours since I did it last.

Before anyone lectures me about waiting so long to do this maintenance, there is a method to my madness.

I purchased my 18ft SeaRay with the engine already attached. The SeaRay has a temperature gauge which tells me a lot. At engine speeds below 2000 RPM the temp stays at 145 degrees because the thermostat is controlling the water flow. At engine speeds between 2,000 and 2,500 rpm the water pump creates enough water pressure to open the poppet valve and then the temp gauge drops down the the peg at 130 degrees.

By watching when the poppet valve opens I have a pretty good idea of the condition of the water pump. Lately the poppet valve hasn't been opening until 2,500 to 3,000 rpm, so I figured it's time for a rebuild.

Here are some pictures of what everything looked like:

After 11 years:

View attachment 418004


Here are the components, the impeller blades are curled, which isn't surprising
View attachment 418005

This upper cover doesn't look good. Unfortunately I didn't buy a new one before I started the job so I elected to put everything back together with the old cover. Ideally a new cover would be better, but everything was working pretty well with this one so what the heck. I'll remember to buy a new cover the next time I do this job.
View attachment 418006

The lower plate has some wear, but I did buy a new one to install
View attachment 418007

I'm surprised at how little wear there is on the impeller, the parting line hasn't even worn down
View attachment 418003

I should note that the upper cover and lower plate are original to the engine, in the past I have always reused them.

Good job with the pictures, thanks.

 

[Chris1956]

Gee, so you would rather watch your temp gauge, than the water conditions, or the kids on the tube or what have you?

Also, if the water pump fails and water stops flowing, the temp gauge likely will not show an issue. A water pressure gauge doesn't have this negative feature.

The upper pump in the picture is beyond use, as it is scored badly. The impeller looks good, but after some years, they start to shed blades. I have had one much younger than yours lose 2 blades. The blades usually fall under the pump base, but sometimes they clog the block.

You got lucky. I would not wait another 11 years.

 

[boscoe99]

Even a blind hog finds an acorn now and again.

Hopefully some aviation mechanic is not following your method of madness.

 

[mike_i]

Personally I wouldn't chance it with my outboard but you beat the odds and definitely got your money's worth. It is interesting/ educational to see that old of a water pump.