Mercruiser 170 - coolant leaking from timing cover - replace water pump

[BlountsBay]

hey everybody. I have a 86 Mercruiser 170 that is in decent shape. Has the coolant leak at the timing cover. I've read a bunch of different posts that seem to be dated over 10 years ago! Not too many recent ones...

I want to replace the water pump instead of dealing with sleeves. I know enough to be dangerous from all these posts I've read. I have the manual but Im having some challenges finding parts.

Besides selling the boat - i know folks will probably give me grief for having this engine - what is a good strategy to be able to make the repair with parts that are easy to get? what parts are easy to get and can I make the repair with them? Like i said before I'd like to replace the water pump to address the leaking seal but i'm having trouble finding one.

I'd appreciate any help I can get. pump, gaskets, what else? Go easy on me!

thanks
BB

 

[Scott Danforth]

welcome aboard.

you need to sleeve the cam snout. no way around it.

 

[stonyloam]

Why do people make this so hard? Like Scott says, sleeve the cam and replace the seals. About a 4 hour job. Don’t waste your time trying to rig something, that chances are would not work. Do a search for “replacing 470 cam seals”. A bunch of folks here have done the job.

 

[stonyloam]

OK the 470 does not have a conventional engine waterpump, so you can not “ replace the pump”. The waterpump is simply a impeller bolted onto the end of the cam that runs inside of the pump housing castings on the front of the engine. There are two seals on the cam that keep the coolant out of the crankcase. Your seals are worn and leaking. The leak you see is coolant leaking out of a weep hole that drains the space between the seals. All you need to do is replace the seals, and if the cam is badly grooved under the seals, repair with a sleeve. Good for 10 years.

 

[BlountsBay]

GOt a guy bringing picker to lift front of motor for repair in a few weeks. I have not opened anything up but trying to get parts ready for when I have his help. I found two speedi sleeves for 7/8 in shaft. One has a longer install tool but the sleeve is gold $. THe other is a cap tool that is shorter than the gold sleeve tool. Can't seem to find info on how long each of the install tools is. Trying to judge tool size by comparison to sleeve...gold sleeve tool looks much longer. Both sleeves are 0.313 in without flange.

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Question is...how long does the install tool need to be? Maybe one gold part/long sleeve to get the tool. ONe gold sleeve and one cheaper ss? Might be worth the extra cost to get the longer tool for the job. I could see the shorter tool not being long enough to get the sleeve to the right spot. Gold won't help but shouldnt hurt. Both sleeves are 0.313 in without flange.

I got some time to order parts so your feedback could help me get the right sleeve and make job easier or cheaper. Cheaper sounds funny... gold part on this motor...

How do you debur the sleeves if they need it? Emery cloth? Don't want to damage sleeve if it is located right.

How important is the loctite 8831 that the manual calls for when set the seals? I see the need for something but are there any subs easier to find that can do the job?

How long should I wait before running the engine up to temp?

I plan on replacing the exhaust elbow gasket and thermostat while I have the coolant drained. I can see a few places where coolant has leaked out at that area. Any gotchas on the exhaust elbow and manifold surfaces? Don't have it torn down so don't know what is waiting to laugh at me! I figured I'd use some JB weld to build up any pitted spots and to bond them to shaft

Getting late. Thanks for the help.
BB

 

[stonyloam]

Are you sure you need to lift the motor? The only reason to lift the motor is if you can’t get a puller on the rotor to remove it from the crank. Borrow a puller from Autozone and see if you can get it on the rotor. If you can, pull it with the engine in place. If you lift the motor you will need to pull the outdrive and realign it before you use it or you may destroy the coupler. I think the loctite is to keep coolant from seeping between the cam and the sleeve, so it is a good idea. So it sounds like you have some time. I would see if you can pull the rotor, then you can pull the front cover and the pump impeller (make sure you turn it the right direction as indicated by the arrow on the impeller if you have the stud rather than the bolt holding it on). Take a look at the cam, if it is not grooved you can replace the seals without using a sleeve. If it is grooved,then the sleeve is a good idea. You will need to rig a tool to pull the rotor back on after the job, but that is pretty easy to do. Be careful pulling the cast covers. Let us know how you are coming along.

 

[BlountsBay]

Hey everyone. I only have about 7" of space in front. Everything I read says you need closer to 10". Does anyone have any feedback for the questions in my earlier post - typed in red letters? Thanks.

 

[stonyloam]

7” should be enough. The only real question is if the center of the rotor is above the deck so you can get the puller on properly.

 

[BlountsBay]

Hi everyone. Have sleeves and seals installed. Ran for 20+ minutes with AF on muffs w/ cap on tight. No leak thru weep hole but leaks on corner of pan gasket. Had to make new pan gasket. Ive read about using some nonhardening permatex and working it into the corners/ends of the pangasket.

Can I use that nonhardening permatex on both sides of the pan gasket and all around timing cover?

Any reason why should not mix non hardening for corners with hardening kind everywhere else?

Any recommendations for oil pan gasket steps?

This will be 3rd time for this repair. Seal was cut on first try. Got new gasket and seals in case they get cut pulling cover off. Pan gasket cut second time.

3rd time is charm right. Thanks