Argh!!!! New water pump is still leaking!

[Newbie@boats]

Well, I recently discovered my water pump was leaking 01 Merc 3.0L so I replaced it with an OEM pump Obviously replaced the gasket and cleaned the surfaces to bare metal.....running my boat on the muffs today I noticed a real slow "seap" of water runs down the timing cover much much slower than it was leaking before and it's almost impossible to see it with the water pump pully.

So just a few questions

A. Could it be a defective pump?
B. Should I have some something differently on install? Applied RTV between the gasket/pump/block?
C. Did I forget to do something? It's a super straight forward job i will pull it apart tomorrow after work and see what I can find was just looking for advice to see if anyone has had this issue before

 

[wrench 3]

All I ever use on a water pump gasket is a bit of chassis grease. It's most likely that you missed some old gasket. It's easy to do, especially if it had a hardening gasket sealer used on it. Lightly sand it with emery cloth and make sure that you have bright metallic scratches over the entire sealing surface.

 

[thumpar]

You need to figure out where is it leaking. Is it at the block or from the water pump itself? It could even be a loose hose clamp.

 

[NHGuy]

I'd clean up the block and the pump. Then level sand them with sandpaper or emery cloth on a flat block. Then put some Mercruiser Perfect Seal on the gasket to stick it to the pump and the block. It's great stuff.

 

[bruceb58]

Did you use RTV? I would not use that at all. Should be able to use the gasket alone.

 

[Newbie@boats]

I actually used scotch brite pads to clean up the surface of the block, it was down to nice shiny clean metal before I installed the new pump and gasket, I will run the boat when I get home and try to move the pulley out of the way right away so I can try to figure out where the leak is coming from....since I got the pump from a local supplier if it is leaking again I can always warranty the pump.

 

[Scott Danforth]

I have a chunk of aluminum that I stick my DA pads to for truing surfaces. I do use a bit of permatex #3 to hold waterpump gaskets in place when replacing pumps. never had one leak yet. if the leak is between the gasket and pump, most likely an installation issue. I have had a new pump start leaking water out the weep hole within hours or replacing.

regarding your ABC questions. Posibly, generally not needed - however sure, dont know - only you can answer

 

[Newbie@boats]

Will have an answer a little later today with what I find.

 

[Newbie@boats]

Well figured out its NOT the water pump leaking

The timing cover rusted thru from the water pump leaking previously







I will get a new timing cover, seal, and belt

Why didn't they make these out of composite or some other sort of material to avoid this?

To much surprise the oil pan gasket stayed competely intact I will apply a real thin layer of "the right stuff" upon install to avoid any oil leaks

 

[bruceb58]

I thought the proper way of replacing the timing cover was to remove the pan. I have never done one but that is what I have read.

 

[thumpar]

I thought the proper way of replacing the timing cover was to remove the pan. I have never done one but that is what I have read.

Same here. Maybe it was so far gone it didn't matter.

 

[bruceb58]

I just looked in my Volvo manual for the 3.0 which is the same engine and it says to pull the oil pan too.

 

[Newbie@boats]

Yes, I have read a bunch of mixed reviews of doing the job.

I'm 99% positive I cannot remove the oil pan from the boat to replace that gasket as well, unless I can lower it enough to drop the pan and replace the rubber gasket? It seems there should be enough room to do that.

Almost like the same thing as doing the water pump seal on a 470 you have to remove the cover which exposes the oil pan gasket which I believe is the cork gasket this being the rubber gasket I think I'd be OK not 100% sure though

I did loosen a few of the oil pan bolts towards the front of the pan

 

[bruceb58]

I have done the "replace the pan" in the boat. I would never do that again. Way easier to pull the engine and do it where you can get everything easily.

With your engine, you could get it out in less than a few hours assuming you can get a lift.

 

[Newbie@boats]

I am pretty confident I will be able to get this to seal up the way it is now, worst case I will pull the motor if I have to, really trying to avoid that option at the moment

 

[Newbie@boats]

Does any one have a sierra part # for the timing cover?

 

[bruceb58]

What is your serial number?

 

[Newbie@boats]

Just went out and checked its a L698020 only reason I am looking for a sierra part # is my local parts supplied carry sierra parts

 

[wrench 3]

We did them in the cars all the time. Remove the front pan bolt on each side and loosen a couple back from there. Use right stuff on the joins between the side pan gaskets, the front pan seal and the timing cover gasket. Put the bottom of the timing cover onto the pan. Kind of angle the bottom in. Pry the cover down with a punch or small screwdriver in a bolt hole on each side and slide the cover back into place.

 

[Newbie@boats]

Another question I have is how do I go about getting the harmonic balancer back on without smashing it with a piece of wood and a hammer? Do they make an install tool?