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I'm at wits end trying to get my water pump to stop leaking at the gasket on my 1967 GTO, 400, 4V. I installed a new Flow-Kooler water pump and new stainless steel divider plates (from Ames Performance) and can't get a good seal on the discharge side of the water pump. In the product description for the divider plates it says some contouring might be necessary. I had to file down the discharge neck on the back plate to get it to sit deeper in the the timing cover.

So far I've tried both Felpro and Mahle gaskets with and without gasket cement. I've tried gaskets with Permatex black RTV and 3M yellow gasket adhesive. I haven't put any thread sealant on the bolts, but I will try that next time. It doesn't appear to be leaking around the bolts, though. The leak is along the discharge side from approximately where the water pump is recessed for the stud & lift eye along that side to the bottom of the pump.

I'm thinking possibly that the front divider plate is falling down out of place when I put the water pump on. I'm considering putting a bit of yellow 3M adhesive on the plate to hold it in place while I install the pump.

Any other considerations? Does anyone have any experience with what sort of recontouring the divider plate need? Ames tech support only told me to file the discharge neck down a bit.

Thanks
 

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Recontouring the divider plate is not something I have heard, but might be more about getting the proper clearance between the plate and the water pump impeller. If the gap is too large, the pump does not work as efficiently.

With the problems you are having, I might think that the surface that the water pump bolts to is warped or damaged. You will need to make sure the mounting surface is flat and even. If there is any pitting, I use JB Weld to fill the pits in after thoroughly cleaning the surface. Then I follow this up with a large file I have which is about 10"-12" long and gently go over the surface keeping the file placed flat on two opposing sides, not just one side, so you get a more even and flat cut. I move the file around in different directions to even up the entire surface.

The yellow gasket adhesive works good in keeping the gasket from moving and slipping out on you. Some of these gaskets are actually too thin or "slick" and can squeeze out when torque down - had that experience once. Makes sure the mating surfaces are roughed up with a little sandpaper. If they are painted, oily, or too slick, the gasket may not hold.

I like to use a product called "Indian Shellac." Old school stuff, but it works pretty good. I believe NAPA is where I got mine last time. Use it on the gasket/flat surfaces only. Do not get the stuff on the bolt threads. It is like honey and takes a little time to set-up, but when it cures, it can glue/lock a bolt in place and you can snap it off when you go to take it out the next time.
 

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Thanks. I'll look at the mating surfaces again. Both the timing cover an water pump are brand new. Torqued the bolts to 180 in-lbs as per spec so I don't think I bent them. I'll dress up the surfaces & give it a try. Attempt #6 this time.
 

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Thanks. I'll look at the mating surfaces again. Both the timing cover an water pump are brand new. Torqued the bolts to 180 in-lbs as per spec so I don't think I bent them. I'll dress up the surfaces & give it a try. Attempt #6 this time.
Where are you coming up with 180-inch pounds? Never seen that in a Pontiac manual. Realize 180 inch pounds = 15 ft pounds. Are you sure the torque wrench is calibrated correctly?

The bolts/nut on the block stud for the timing cover to block get 30 ft lbs. The nuts for the water pump to timing cover get 15 ft lbs.
 

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Discussion Starter #5
15 ft-lbs is listed in the specs in the shop manual for the water pump bolts. My torque wrench is graduated in in-lbs, hence the 180 in-lb torque. I suppose I could get a scale to calibrate the torque wrench.
 

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Hello, did you every get this issue resolved. I have a 1967 GTO and it has the same issue. Engine is rebuilt with all new parts. Have not even run engine yet and it leaks at the gasket. I checked the torque with 2 torque wrenches and I have a digital torque block that I also rechecked the torques. All are 15 ft-lbs as per the spec. Seems too low to me (my opinion) Not sure what to do next but will disassemble and look at those divider plates and recheck the clearances. Just hoping to save some trial an error here. Thanks
 

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Hello, did you every get this issue resolved. I have a 1967 GTO and it has the same issue. Engine is rebuilt with all new parts. Have not even run engine yet and it leaks at the gasket. I checked the torque with 2 torque wrenches and I have a digital torque block that I also rechecked the torques. All are 15 ft-lbs as per the spec. Seems too low to me (my opinion) Not sure what to do next but will disassemble and look at those divider plates and recheck the clearances. Just hoping to save some trial an error here. Thanks
My '68 Service Manual says 15 lbs for the bolts that hold the water pump to the timing cover. The bolts that hold the timing cover to the block are 30 lbs. Fan/pulley to water pump is 20 lbs. It says stud on the timing cover (water pump attachment?) that has a nut, 15 lbs. Long bolt that goes into the intake water outlet, 15 lbs.

To correctly install the timing chain cover, and where many leaks occur and can't be seen, it from the rubber O-ring seal that goes from the timing cover to the front manifold water outlet.

The best way to ensure this does not leak, is too have the intake loose. You torque down the long bolt to 15 lbs that runs into the intake first. This draws the intake in and tight against the O-ring to seal it. Then you torque down the intake.

The intake has to be free to slide a little, so if you are not installing new gaskets on the intake, then it is most likely stuck into position and will not draw forward.
 

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Lot’s of great tips to help you so far. I would recommend getting a can of ......K&W copper coat Gasket Compound, at your local auto parts or online. It has a small brush applicator, the floating copper seals any imperfections in the gasket to metal surface. It takes high temps gets tacky, to hold gasket, and most of all it is the only sealer that I have never had leak.....

Like PJ I have used Indian Head shellac for years, but have had that leak, likewise RTV, have had that leak. But this stuff has always held on water pumps thermostats etc.

Try that stuff, and repeat your correct torque sequence crisscrossing etc. you might have to consider a new identical water pump...

If that surface is too warped to seal, even with PJ’s filing recommendation. Which may work.

You can also use studs and nuts instead of water pump bolts, to try to get it to seat properly. Should not make a difference really, but sometimes the small things matter, and it just might pull it in a micro better.

Good luck you will get it!:nerd::nerd:
 

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Thanks for the information.
I used aviation gasket sealer. That is what my engine rebuilder recommended.
I also did all the proper torquing and crisscross patterns, etc.
I believe I got the O ring in correctly as I tightened the intake and the long bolt together. There was no leaking there or around the timing cover to block. Just around the water pump to timing cover.
All parts are new so no pitting to deal with ( that is why I got the new parts). Anyway, I will finish disassembly and check those aftermarket parts for high spots and clearance issues. Hard to check the water pump for flatness as the impeller is sticking out and in the way.
 

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Thanks for the information.
I used aviation gasket sealer. That is what my engine rebuilder recommended.
I also did all the proper torquing and crisscross patterns, etc.
I believe I got the O ring in correctly as I tightened the intake and the long bolt together. There was no leaking there or around the timing cover to block. Just around the water pump to timing cover.
All parts are new so no pitting to deal with ( that is why I got the new parts). Anyway, I will finish disassembly and check those aftermarket parts for high spots and clearance issues. Hard to check the water pump for flatness as the impeller is sticking out and in the way.

One more thing I would check. Make sure the water pump is not bottoming out against the timing cover. Aftermarket "anything" is usually not the same as original factory. I might put some Playdoh on the timing cover behind the center shaft of the water pump and then attach the water pump with 2 bolts just to draw it snug, then unbolt to see what kind of impression it leaves just to make sure it is not hitting/binding for some reasons and keeping the water pump from fully seating at the seal.
 

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I had a similar problem. I did not notice the divider plate had dropped down and after I torqued down water was linking from bottom of pump. The sad part of my story was that I thought it was a torque issue- and went back to the bottom studs (8 bolt pump). I tightened just enough to crack my new flow kooler. I finally figured out it was the divider plate. Had to grind 1/8 inch off to get it to sit right in timing cover. Used some job weld to hold it in place. I’ve heard others have welded the divider plate in. Anyway, i would check that divider plate...
 

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Thanks Jim. I found the water leak issue. One of the divider plates slipped between the pump and timing cover. Not sure how I let that happen. Anyway easy fix. However I thought I would recheck torques on other bolts. Some where not good. Bad news is I turned the long bolt and about 18 ft lbs it broke off at the intake manifold. I know it says 15 ft lbs and I was just confirming with a little extra. Now I tried to drill it out and need to get a helicoil kit. I think that original bolt was rusty and maybe stretched from before that is why it broke so easily. Anyway, the fun continues.
 

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Thanks Jim. I found the water leak issue. One of the divider plates slipped between the pump and timing cover. Not sure how I let that happen. Anyway easy fix. However I thought I would recheck torques on other bolts. Some where not good. Bad news is I turned the long bolt and about 18 ft lbs it broke off at the intake manifold. I know it says 15 ft lbs and I was just confirming with a little extra. Now I tried to drill it out and need to get a helicoil kit. I think that original bolt was rusty and maybe stretched from before that is why it broke so easily. Anyway, the fun continues.


OK, sounds good. Yep, that bolt should not have snapped at 18 ft lbs, so it may have been a little on the weak side. A helicoil may work, never had to personally use one. Have you thought of using an easy-out to back the broken bolt end out? Sometimes this will work pretty good and since you know it is not rusted into place, might work. They sell them at places like Home Depot/Lowe's, auto parts stores, and online.
 

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Water pump stud sealant

Great thread and I'd like to jump in with a related question, if I may. The 3 bolt holes at bottom of an 8 bolt water pump penetrate the timing cover into the water jacket. Should sealant be used on the studs at timing cover? If so, what should be used? ('65 389)
 

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Great thread and I'd like to jump in with a related question, if I may. The 3 bolt holes at bottom of an 8 bolt water pump penetrate the timing cover into the water jacket. Should sealant be used on the studs at timing cover? If so, what should be used? ('65 389)
Yes, I would use sealant on them. Probably any RTV silicone would do the job as you are only using a little on the threads and not using the RTV as a gasket sealer. They do may a specific gasket maker for water pump and thermostats, but this would be in place of a gasket.

Might even use pipe dope used on household water pipes when doing plumbing. So your choice. You just do not want something like Indian Shellac or other sealers that will harden or bond the bolts and lock them in place - you'll probably break the bolts off trying to remove them if you ever need to do this again.
 
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