Water pump rebuild after 11 years and 600 hours

[MercGuy]

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:




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


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.


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


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


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

 

[DeepCMark58A]

Well that old impeller didn't owe you anything.

 

[alldodge]

The dice were rolled and you won

So after all this time it shows that the pump housing and wear plates are really worn. So your rolling the dice again with parts that need to be replaced IMO

Good luck

 

[DeepCMark58A]

Yeah gambling and losing causes a mess.

 

[MercGuy]

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

 

[Mc Tool]

If nothing else piece of mind is worth the cost of the new parts .
I dont think its going to fail tomorrow but Id be replacing it as soon as practical.

 

[Mc Tool]

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 do they say ?........its your funeral
And the likelihood of something like that biting you on the arse increases exponentially if you know about it and do nothing

 

[MercGuy]

To be clear, the only part that wasn't replaced was the cover, and I already stated that I will replace it the next time.

 

[alldodge]

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

Yeeeesss I read that part
You decided that I'm going to watch my gauge and if it changes I'm shutting my motor down no matter where I'm at. So you didn't need to be towed or half to paddle back 100 yards to 5 miles, you win

 

[MercGuy]

Well, the point of my post was to allow people to see what kind of wear occurred after a long period of time. Simply sharing information.

But, instead it seems the only interest here is to be judgemental.

Enjoy !!

 

[DeepCMark58A]

Hard to argue what didn't happen. The OP was mindful of temperature and water flow.

 

[alldodge]

Well, the point of my post was to allow people to see what kind of wear occurred after a long period of time. Simply sharing information.

But, instead it seems the only interest here is to be judgemental.

Enjoy !!

Not judgemental at all, you rolled the dice and you won, same is if someone decided I'm not going to change the oil in my car/truck and I sold it with 150K miles and it's still running. Yaah you win

 

[Mc Tool]

Well, the point of my post was to allow people to see what kind of wear occurred after a long period of time. Simply sharing information.

But, instead it seems the only interest here is to be judgemental.

Enjoy !!

I dunno if judgmental is the right word , but I do appreciate the informative intent of your post.
I got roasted on a motorbike forum when I posted that I had left cam belts on for 20,000kms instead of the 5000kms all the hysterical peeps were cryin about ....coz "if it breaks it will destroy the whole motor "....which is true, but nowhere could I find someone who had a cambelt fail ......at all let alone at 5000kms , oh everyone knew of a guy who had a friend whos cousin had one break . My opinion was that its bulls hit ....my car does over 100,000 kms on a cambelt and my bike doesnt even have valve springs so the load is way less and the number of teeth on the belts isnt a factor of the pulley teeth so the load is not on the same part of the belt bla bla bla . But that waterpump is a bit different .I have personally seen them fail ....more than once .

 

[MercGuy]

Not judgemental at all, you rolled the dice and you won, same is if someone decided I'm not going to change the oil in my car/truck and I sold it with 150K miles and it's still running. Yaah you win

I think there is a huge difference in those 2 situations. It is undeniable that not changing engine oil causes severe and permanent damage.

A worn pump cover reduces the efficiency of the pump, but the pump design produces plenty of flow and pressure regardless.

I don't believe that the worn cover will cause a catastrophic failure, as demonstrated by the fact that their isn't any damage to the old impeller related to the cover wear.

 

[nola mike]

Idk, nothing on either of those plates look like it would keep the impeller from sealing reasonably well. What would be the catastrophic failure that you'd worry about?

 

[bajaman123]

Yours is definitely the winner as far as hours go! I've had friends and family that got close to 500 hours out of the pump on an Alpha.
After all this time, what made you decide to change it? Did I miss that in your post?

 

[Lou C]

I bet you're not in salt water. Because if the last guy who did it (either at the factory or dealership) didn't coat the threads of the bolts with Merc Perfect Seal, or OMC gasket Sealer, or Permatex Aviation, in salt water you most likely would have had to fight them for a while, using heat and patience.
I had to remove water pump plate bolts on my Cobra outdrive used in salt water for at least 25 years. Now this part you don't remove for an impeller change, only gets changed if the seal for the shaft that drives the water pump leaks. I know for sure my past OMC mechanic always used the gasket sealer on bolts pretty much everywhere on the outdrive. Well don't you know they came right out and the last time this job had to be done was in 2006! I have followed his advice all these years and still have a nice big can of Evinrude Gasket sealer that I use on everything even on suspension bolts on my Jeeps.

the bolts that were holding it on were in the two holes in the upper part of the plate and you tap holes in the other three openings to push the plate off the upper gear housing with grade 8 bolts. Worked like a charm.

I change the Cobra impellers every 3 seasons, like thermostats, or sooner if needed.

 

[airshot]

Well, the point of my post was to allow people to see what kind of wear occurred after a long period of time. Simply sharing information.

But, instead it seems the only interest here is to be judgemental.

Enjoy !!

Not judging at all....you got lucky. You might stop and pickup a few lottery tickets and see if your on a roll ! I certainly would.....

 

[MercGuy]

At the risk of belaboring the point some of you may want to see this page from my official Mercury Service manual. Note the bold paragraph marked "Important" and item #5

I think I'm good to go

 

[MercGuy]

Yours is definitely the winner as far as hours go! I've had friends and family that got close to 500 hours out of the pump on an Alpha.
After all this time, what made you decide to change it? Did I miss that in your post?

I wrote this in my original post:

"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."