Replacing Liner in Water Pump

[burgessm84]

I bought the parts to replace the impeller on an 1998 Mercury 3.3. It's 10 years old but hardly used - and not run at all for at least 4+ years. Apparently the impeller had dry rot, so when I fired it up, the impeller literally disintegrated. When I took it apart there were tiny bits of plastic everywhere and what looked like smooshed up plastic on the impeler liner (round metal insert to the pump housing that the impeller spins in).

It came apart pretty easily and I was all ready to replace the liner but I couldn't figure out how to remove it. Long story short, I ended up breaking the pump housing trying to get the line out.
Question #1: How was I meant to get the liner out? It's all smooth, with nothing to get a grip on?
Question #2: I have a new housing in the mail - how am I meant to push it in? I get the feeling it's going to be a very tight fit. The only thing that stops it spinning is a very small dimple of plastic that fits in a hole in the liner, and a small bent tab of the liner that fits in the housing - so I'm worried that if I lube it up to get it in, it might spin inside the housing?

Two related questions:
#3 - I did not get gaskets - from everything I read it seems that just replacing the impeller is pretty standard. I only took the housing off, so I've exposed only the top most gasket's mating surface. It looks really good. Do I need to use any gasket sealer on this part before putting the housing back on?
#4 - What should I clean the parts in/with?


Thanks for your help - as I've come to expect, my engine repair manual left out some of the details on a really basic job (how to remove the liner, press in a new one), while including dozens of pages on how to tear down the entire engine.

Thanks again,
Mike

 

[Chris1956]

Re: Replacing Liner in Water Pump

Mike, The liners on the large Merc water pumps are a snug fit in the upper water pump housing. They do not use any sealer or gaskets, like the Johnnyrudes. When you replace the upper housing that you broke, won't it come with a liner already installed? Also, you need to replace the gaskets when you renew the impeller. Although you can buy just the impeller, normally you would get a water pump repair kit which has impeller and wearplate, gaskets, orings, keyway and water tube guide.

 

[emckelvy]

Re: Replacing Liner in Water Pump

Mike, sounds like that "smooshed up" plastic housing was melted. Typically this'll happen if the motor is run out of the water or somehow run dry while on the boat in the water. Dry running creates loads of friction which will melt the plastic housing and eat up the impeller in short order.

Sometimes you can clean up a housing like that if it's not melted too badly but usually it's better to replace it. Might be warped from the heat and not seal properly.

Typically on a melted housing you're not gonna get the insert out anyway. Even on an undamaged one they're usually quite tight and to get the insert out, you have to drive it out from the top, which most times ruins the insert. But you wouldn't want to take it out if it were good!

HTH..............ed

 

[burgessm84]

Re: Replacing Liner in Water Pump

Thanks for the responses. They seem to sell the housing and liner seperately. I looked to drive the line out from the top - but it did not protrude into the hole where the drive shaft comes through - so nothing to hit with a screwdriver. I actually took a chisel and tried to bend in the top (bottom reall) of the line where it stuck out a hair beyond the flat part of the housing. I wanted to bend it in so I could grab it with a lockwrench or something - that's how I busted the housing....

My housing is in - I'll give it a go this weekend.

Thanks again,
Mike

 

[burgessm84]

Re: Replacing Liner in Water Pump

It works! New liner went right into the new housing - so I'm thinking maybe you were right about the old housing getting a little melted. Ended up using a little gasket sealer since I didn't replace them. Next time I guess I'll look for a kit. Of course Saturday night I ended up going to 4 different stores looking for an o-ring I somehow misplaced - but that always seems to be the way things go, and it took about 45 minutes of fiddling throught the little access port trying to line the water tube up with the outlet in the housing as I pushed the lower unit back in. Still - it cost way less than paying someone to do it, and now I'll know how to do it quicker and cheaper next time.

Thanks again for the advice,
Mike