As they say aluminum pits easily, and I just discovered a tiny pinhole in the aluminum cylinder head at the water outlet slowly seeping coolant. Would JB Weld work here? Is there a better alternative?
JB Weld or what for a pinhole seeping coolant?
- Thread starter Gokhan
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On the water outlet id do it. On a head where it mates up to the outlet i would try it. On an actual vertical water passage where there is head mating to block involved I'm sure it's been done but no personal experience there. It doesn't hurt to try a 10 dollar fix.
Napa sells a putty, black with a gray center, that you knead together. I used it on a gas tank and it worked great!
Yep, it will work perfectly in that application. Just clean it up really well before applying. I'd put an awl in there though just to "open up" the hole a bit. Where there's a pin-hole leak, there's probably corrosion surrounds in, and you want all of the corroded stuff out of there.
I did this repair on my Eurovan and I got about 50K miles out of the repar before electrical gremlins led me to give away the vehicle.
I did this repair on my Eurovan and I got about 50K miles out of the repar before electrical gremlins led me to give away the vehicle.
If that doesn't work you can drill, tap and put a screw in with an o-ring.
a pin hole, JB will do it...not sure why one would want to drill out an 8th inch hole, but u know,,,what do I know,,,why not a half inch hole.................
It could be one or a couple of pinholes in the same small area or perhaps also a hairline crack. When I get a chance, I'm thinking of cleaning it with brake-cleaner fluid and then using some sandpaper to prepare the surface (and clean again with brake cleaner) before I apply a generous amount of JB Weld in the area.
It looks like it could have been caused by the water-outlet gasket leaking and exposing the area to coolant (Prestone Dex-Cool) and air, which is probably a corrosive mix.
Just replaced the water-outlet gasket and flushed the system twice with distilled water. The new fill: Toyota OEM Red (not Pink) ~ 53% and distilled water.
It looks like it could have been caused by the water-outlet gasket leaking and exposing the area to coolant (Prestone Dex-Cool) and air, which is probably a corrosive mix.
Just replaced the water-outlet gasket and flushed the system twice with distilled water. The new fill: Toyota OEM Red (not Pink) ~ 53% and distilled water.
Back in the day when aluminum casting porosity was common the OEM "fix" was epoxy.
You do need to drain some coolant out so the area stays dry until the epoxy cures.
It only takes a thin coat pressed with a squeegee into the pin holes.
You do need to drain some coolant out so the area stays dry until the epoxy cures.
It only takes a thin coat pressed with a squeegee into the pin holes.
Originally Posted By: Trav
Back in the day when aluminum casting porosity was common the OEM "fix" was epoxy.
You do need to drain some coolant out so the area stays dry until the epoxy cures.
It only takes a thin coat pressed with a squeegee into the pin holes.
Thanks, good advice. You're probably right that casting imperfections are partly to blame.
It's facing up at the very top of the cylinder head; so, I think it will stay dry even if I don't drain the (newly replaced) coolant. I think it only seeps when the engine is hot and running.
Back in the day when aluminum casting porosity was common the OEM "fix" was epoxy.
You do need to drain some coolant out so the area stays dry until the epoxy cures.
It only takes a thin coat pressed with a squeegee into the pin holes.
Thanks, good advice. You're probably right that casting imperfections are partly to blame.
It's facing up at the very top of the cylinder head; so, I think it will stay dry even if I don't drain the (newly replaced) coolant. I think it only seeps when the engine is hot and running.
ideally if you can force it as deep into the pin hole as possible and create sort of a plug with the epoxy, it will be the best possible repair.
GM tabs are also OEM recommended for porosity issues in areas that cannot be reached to epoxy over.
The ginger root is permanent in these kind of situations and will not clog anything.
Maybe a double fix, inside and outside.
GM tabs are also OEM recommended for porosity issues in areas that cannot be reached to epoxy over.
The ginger root is permanent in these kind of situations and will not clog anything.
Maybe a double fix, inside and outside.
Originally Posted By: Trav
ideally if you can force it as deep into the pin hole as possible and create sort of a plug with the epoxy, it will be the best possible repair.
GM tabs are also OEM recommended for porosity issues in areas that cannot be reached to epoxy over.
The ginger root is permanent in these kind of situations and will not clog anything.
Maybe a double fix, inside and outside.
Thanks for the info and heads-up on this material.
The pore in the cylinder head that is seeping coolant is so small that it's almost invisible. I don't think you can force the epoxy in it because it's so minuscule.
I think Prestone Dex-Cool is what partly caused the damage. These extended-life OAT coolants seem to be corrosive when exposed to air and I had a leak at the water-outlet gasket and the leaking coolant seem to have corroded the area and eaten away the gasket. I just replaced the gasket with a new OEM one.
I'll start with the epoxy and if the coolant consumption doesn't go away, I'll use these almond-shell-and-ginger-based ACDelco cooling-system seal tabs.
Do you have any suggestions on the brand/type of epoxy?
ideally if you can force it as deep into the pin hole as possible and create sort of a plug with the epoxy, it will be the best possible repair.
GM tabs are also OEM recommended for porosity issues in areas that cannot be reached to epoxy over.
The ginger root is permanent in these kind of situations and will not clog anything.
Maybe a double fix, inside and outside.
Thanks for the info and heads-up on this material.
The pore in the cylinder head that is seeping coolant is so small that it's almost invisible. I don't think you can force the epoxy in it because it's so minuscule.
I think Prestone Dex-Cool is what partly caused the damage. These extended-life OAT coolants seem to be corrosive when exposed to air and I had a leak at the water-outlet gasket and the leaking coolant seem to have corroded the area and eaten away the gasket. I just replaced the gasket with a new OEM one.
I'll start with the epoxy and if the coolant consumption doesn't go away, I'll use these almond-shell-and-ginger-based ACDelco cooling-system seal tabs.
Do you have any suggestions on the brand/type of epoxy?
JB weld is good stuff, good to 550F IIRC which is good enough for the head. This doesn't sound serious.
We use to have transmissions come in with the case wet in patches. Some of the early N* engines would be damp in areas before GM started using the tabs.
Like you say the addition of the corrosive effects of the coolant may have contributed also
We use to have transmissions come in with the case wet in patches. Some of the early N* engines would be damp in areas before GM started using the tabs.
Like you say the addition of the corrosive effects of the coolant may have contributed also
I haven't done this particular repair with JB Weld, But I used it to repair a cast aluminum recoil starter housing on my Stihl. Also, after wire wheeling the rusty spots on a 528e gas tank, several pin holes were uncovered. I bought the large tubes of JBWeld and applied it with a 4" taping knife. Follow the directions on the tube. Clean the area, removing all loose material. Apply a JBWeld to the area. Dam up the perimeter. It will flow for a while. Let it cure overnight. Longer is better.
Well, I did the J-B Weld repair. I Used the original J-B Weld, carefully mixed it 50/50, cleaned the area with CRC brake cleaner and shop towel, sanded with coarse (40-grit) emery sandpaper with J-grade backing, and then cleaned it again with CRC brake cleaner. It was very hard as it was quite out of reach. Then I waited for 24+ hours for it to cure.
It looks like the leak wasn't from the aluminum but the bolt hole for the water outlet. Either the gasket repair didn't work perfectly or there is too much corrosion at the mating surfaces, especially near the bolt holes.
Anyway, the leak seems very small. It could come to less than a quart in 30,000 miles. So, I'll just keep an eye on the coolant (Toyota Long Life Red) level for now.
Perhaps I should just cover the bolt hole with adhesive silicone to see if it stops the seep.
It looks like the leak wasn't from the aluminum but the bolt hole for the water outlet. Either the gasket repair didn't work perfectly or there is too much corrosion at the mating surfaces, especially near the bolt holes.
Anyway, the leak seems very small. It could come to less than a quart in 30,000 miles. So, I'll just keep an eye on the coolant (Toyota Long Life Red) level for now.
Perhaps I should just cover the bolt hole with adhesive silicone to see if it stops the seep.
I doubt the silicone will hold a leak. If the cooling system wasn't pressurised, maybe.
Originally Posted By: Gokhan
It looks like the leak wasn't from the aluminum but the bolt hole for the water outlet.
Use a thread sealer on the bolt threads and perhaps some ginger tabs that are recommended for the GM Northstar engines.
It looks like the leak wasn't from the aluminum but the bolt hole for the water outlet.
Use a thread sealer on the bolt threads and perhaps some ginger tabs that are recommended for the GM Northstar engines.
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I think what happened is that a groove that developed at the bolt hole (I saw it when I replaced the gasket) extends beyond the gasket and some coolant seeps through the bolt threads. If I knew that beforehand, I would probably try using some silicone on the threads, but it's too late now. Anyway, I can only hope that the seep is very small so that I have to top off the coolant no more than once a year.
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