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Discussion Starter · #1 ·
Hi all,

I seem to be having a persistent issue with a small coolant leak at the top of my water pump.

At first I thought this was the O-ring seal in the head. I recently replaced the head gasket and O-ring, and realized that I was still seeing this leak. Careful examination indicated that the leak is actually coming from the water pump gasket, not the head. I bought the water pump in 2019 from OGTS and have installed it a total of three times (first to replace the worn-out pump that came with the car, then this summer as part of a comprehensive gasket replacement, and in the last couple of weeks in an attempt to fix the leak which was still evident).

Here's a photo from this morning's road test. Several small drops can be seen coming from the gasket. Eventually these puddle in the valley near the larger drop.

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This is the area on the gasket that I think is giving me trouble. The red rubber bead is very close to the edge here (it has been the same on all my gaskets, also OGTS items). I tried as carefully as I could to attach the gasket to the pump "within the lines" as it were, but as one can see in the photo above, the gasket does seem to "bunch up" and protrude here:

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The corresponding area on the pump seems to show an area where that bead is off the edge:
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This time, I tried coating both sides of the gasket with a thin layer of the black Permatex, hoping that might fill in any small gaps.

I checked the pump for flatness and it seemed good.

Has anybody else had a similar problem with these gaskets? I'm willing to throw another pump on it if that would fix the issue, but I feel like maybe I'm missing something. I torqued the bolts in a criss-cross pattern using two or three progressive steps, so I don't think that is the cause. I'm thinking about making my own gasket to get rid of the rubber bead and to achieve a better fit in the affected area.

I really hate draining the coolant, so hopefully the next time will be the charm...

(On the bright side, I do seem to have exorcised the oil leaks from my front and rear crank seals and from my transmission :)

Thanks,
Bob
 

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Opel Rallier since 1977
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Can't say I have ever used those gaskets with the pre-made red bead of sealer. I've always used a thin, flat paper gasket; nary a water pump leak in 45 years and many installations. I have to wonder if that red bead is acting to distort the pump housing a bit right there. Perhaps ditch that gasket style and get just a thin paper one.

Your use of the black RTV is good; use just thin coats. And install the pump/gasket with the bolts barely snugged up, but do not tighten. Let the black RTV set up for 1-2 hours; it takes that amount of time to get a bit hard. Only then torque in the bolts. If you tighten the bolts too soon, the RTV simply acts as a lubricant and actually makes it much more likely that the gasket will move.

Glad to hear about the oil leaks!
 

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I recently (last year) replaced my water pump with the same gasket but used permatex high tack I believe and a little dap on the bolts as well let it sit for an hour maybe then snugged everything down and haven't had an issue is it possible you have a small scape or something whre it mounts or possibly the pump?
No oil leaks is always a good feeling. I dont have to keep fresh cardboard under mine anymore to help me find the leaks LOL
 
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Über Genius
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Over torqueing the pump can cause leaks.
There's nothing wrong with tossing in a can of Bars Leaks and calling it good.
 

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I used Permatex Copper Spray-A-Gasket Sealer on my water pump and thermostat gaskets and no leaks. Might be worth a try. It's easy to spray on a nice even layer.
 

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Just Some Dude in Jersey
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I use the Permatex red, which is made for water applications, black is for oil applications. I have also used the copper spray. I have never seen or used the gasket you used with the red bead printed on it. Like Manta Rallier, I have used the plain paper gasket for 40 years and never had a leak at the gasket.
 

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Detritus Maximus
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You guys and your new fangled hi-technology!...all I've ever used for my gaskets is Indian Head. Available at finer Autozones...

Any chance the bolts in that area are not threading all the way in for some reason? Or a burr on the timing cover?
 

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Living in the past
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I use the Permatex red, which is made for water applications, black is for oil applications. I have also used the copper spray. I have never seen or used the gasket you used with the red bead printed on it. Like Manta Rallier, I have used the plain paper gasket for 40 years and never had a leak at the gasket.
Indian Head gasket sealer is the hot lick, comes in a small can with a brush attached to the lid. Light coat on the gasket and a light coat on the metal gasket surface and you are good to go. I have assembled at least 200 engines over the years using Indian Head and NEVER had one leak, of course you must make sure both surfaces are clear before assembly. I have used it on water pumps, oil pan gaskets, valve covers, front cover to the block, cork part of the head gasket to the front cover and transmission gasket to bell housing and in 50 years I never had one leak.
 

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Opel Rallier since 1977
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2,278 Posts
I use the Permatex red, which is made for water applications, black is for oil applications. I have also used the copper spray. I have never seen or used the gasket you used with the red bead printed on it. Like Manta Rallier, I have used the plain paper gasket for 40 years and never had a leak at the gasket.
That is the point of the thin paper gaskets with items that can flex, like aluminum parts and oil pans.... paper gaskets don't compress like a thicker, softer gasket, which tends to bow the housing when the bolts are torqued. The paper gasketing is used on the AL oil pump cover and behind the timing cover for that reason. Any flexing of the housing where there is pressure behind it is going to tend to leak.

I suspect that the illlustrated soft gasket is the main culprit here.

And these bolts don't get much torque on them... 11 ft lbs. I just make sure they are snug and no more.
 

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You guys and your new fangled hi-technology!...all I've ever used for my gaskets is Indian Head. Available at finer Autozones...

Any chance the bolts in that area are not threading all the way in for some reason? Or a burr on the timing cover?
hahaha new fangled I'm just young enough to have never heard of indian head
But I will be looking for some now LOL
 

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Just Some Dude in Jersey
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I was also told by OGTS to never tighten bolts all the way right away when using liquid/tube sealers. Just firm hand tight. Best to wait overnight, then do final torquing. Permatex is called FORM-a gasket, which means it FORMS a gasket. If you tighten all the way right away it all mostly squeezes out leaving not much to form a gasket.

I'm sure racer dudes who are constantly rebuilding their engines, sometimes after every race, will disagree, but since I have adopted the wait-to-torque method I have had my best results. :)
 

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Über Genius
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There's a real possibility (probability) you have a hairline crack you can't see. No way can I believe you installed 3 gaskets and have a small "gasket" leak at the same spot each time.
 

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Detritus Maximus
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I had forgotten about a pump I had with a hairline crack. Although it was the result of an accident.
 

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Discussion Starter · #15 ·
Hi everyone,

FWIW I purchased a couple of those eBay gaskets but they seem to have shrunk such that they wouldn’t fit. Not sure if they’re old stock, but they did have little Opel “eye” logos stamped into them. So I wanted to give potential followers of this thread a heads-up.

Anyway, I ended up making my own gasket from 1/32” Fel-Pro gasket sheet. I used copper spray as well, and I replaced the pump since OGTS had them on sale. Leak is fixed now. I can’t see anything wrong with old pump but can’t say for sure whether it was part (or all) of the problem.
 

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Opel Rallier since 1977
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Good deal, bolbers. Glad you got it. I just don't think that OGTS gasket material is right for this application; too squishy and allows the pump flange to distort a bit when tightened, plus the red sealer line is not well done and is not a consistent thickness. Your thin gasket material is the right way to go.

BTW, I bought 3 of those eBay gaskets and they fit except for one hole being off about 1/16". But I have been seeing these gaskets a bit off here and there for many decades. Sometimes they get folded in the gasket kits and you have to work with them a bit.
 
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