Can't get water pump to seal

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Chopper3200

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Iowa
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1997 Cougar 4.6L
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Hello! Does anyone make a 4.6 engine block water pump bore shim I could JB-Weld in to get a smooth sealing surface? Mine is so pitted from rust and corrosion It won't seal up anymore for more then a couple months at a time, even with a new oring and sealant. Thanks.
 
Assuming you are repairing this in the vehicle? Probably need to use a cylinder hone to open it up a little then install a speediSleeve with proper adhesive. if out of the car then a machinist could do a better job.

SKF

www.skf.com www.skf.com
 
Do not JB Weld your water pump in. Just clean up the sealing surface with a red cookie on a die grinder, or some 80 grit sandpaper, and then use a new o-ring and coat it with a thin coating of grease. That should seal, but on the off chance your block really is that pitted and it won’t seal, just follow the same procedure with some RTV instead of grease, and let it cure overnight before filling it up with coolant.
 
MadMikeyL said:
Do not JB Weld your water pump in. Just clean up the sealing surface with a red cookie on a die grinder, or some 80 grit sandpaper, and then use a new o-ring and coat it with a thin coating of grease. That should seal, but on the off chance your block really is that pitted and it won’t seal, just follow the same procedure with some RTV instead of grease, and let it cure overnight before filling it up with coolant.
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I was actually going to suggest JB weld. Years ago when replacing the intake on my dads old 5.4 F150 we found the aluminum was badly pitted at the water ports. We filled them in with JB weld and sanded it smooth. It never leaked for many years after.

But I agree that RTV like you suggested seems a better option for the water pump
 
I wouldn't JB Weld the water pump in, but I have seen people repair pitted surfaces like that with JB Weld. It might be tedious to get it right and it depends on if you have enough guide surface to work with. You also need to get the pitted surface as clean and rust free as possible. Dress it up and sand it smooth and then install the w/p as usual.
 
I had actually tried JBWeld to fill in the pitting before but it didn't hold, corrosion formed around the edge and under the weld and it started leaking again thats why I was wondering if anyone made a shim for the hole bore. I was able to find a slightly larger oring on amazon https://www.amazon.com/dp/B07GXD7XJJ and used the permatex water pump/thermostat sealant, hopefully it will last more then a few months.
 
jb weld contains iron, so it will corrode any aluminum you apply it to. Black rtv will fill the pits and stay there, I fixed a manifold like that. The key is getting all the corrosion out first.
 
Lol. you are correct the iron block will not do galvanic corrosion, which the description fits i guess the corrosion I saw was the aluminum pump in the steel block. My corrosion was from 3yo stock ,coolantI had manifold leaks and had to use a slide hammer to get the wp out
 
How deep are the pits? If they’re not terribly deep you might be able to use a flap wheel drill attachment and smooth it out and still have enough area for the O ring to properly seal.
 
Chopper3200 said:
I had actually tried JBWeld to fill in the pitting before but it didn't hold, corrosion formed around the edge and under the weld and it started leaking again thats why I was wondering if anyone made a shim for the hole bore. I was able to find a slightly larger oring on amazon https://www.amazon.com/dp/B07GXD7XJJ and used the permatex water pump/thermostat sealant, hopefully it will last more then a few months.
Click to expand...
When I had problems with pitting, it was at the back of the intake manifold; The key to getting a seal was using a metal pick tool to get every bit of corrosion out, or it will leak again. Most metal oxides dissolve in hot water. backfill the pits with black or copper rtv, (rated for engine temps), use a piece of cardboard to smooth the surface, and give it 24 hours before putting it back together. Usually where you have this corrosion, it's the aluminum that corrodes, which is the wp, not the block.
:zshrug:
 
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