Please Help

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Jul 30, 2003
Hi, I returned from a short drive today and noticed a pin sized hole in the upper front of my radiator. An equally small spray of coolant was almost misting out of it!!! Yikes. I'm a new FJ40 owner (1978) and am not sure what to do about this. Can a tiny hole like this one be fixed or do I need to replace the whole thing? I let it cool down for a little bit and the leak stopped after about 10 minutes or less. I assume I should not drive it. Do I need to drain it and remove it? Please help, I just got it and it is now sitting.

Thanks a lot for any advice about this.
I beleive it is a 4 core radiator from a place called "desert cool."
You could go to the auto store and get some of the leak stop stuff they sell or call a radiator shop and get them to fix it. IMO, I would take it to the shop. I dont trust the leak stop.
Thanks for the advice fj40mayo. Do you mean, drive it to the shop or take out the radiator and bring that to the shop?

Thanks again
If you're going to drive it, I would add the leak stop. That might get you by for now. Call the radiator shop and ask them if its cheaper if you pull it and bring it to them. They can take it from there.
If you are up to it, you can repair the pinhole yourself. I have done this on a few radiators with pinholes, and help fix a fan chewed radiator once too with this method.

Get yourself some radiator solder, it will have an acid filled core. got out your handy propane torch. Clean around the pinhole with steel wool, heat up the area with the propane torch, and solder the hole shut. It can be done with the radiator in the rig, unless you can't access the pinhole.

Give it a try, if that don't work take it into a radiator shop.
If this vehicle is new to you, you might be ahead of the game if you pull the radiator, take it to the shop and ask them to repair it, pressure test, and flush or rod it out. When you put it back in, new hoses and the right coolant. That's an old truck, and this will be one less thing to worry about.

Mike S
Radiator shops hate that stop leak crud. I didn't know why till I learned how to do my own repairs. Every time I'd fix a leak another would show up. Turns out the heat from soldering would dislodge the stopleak from other holes that didn't show up in previous pressure tests. My advice is to take it to a reputable rad shop and do it right the first time. Like Mike said, one less thing to worry about.
Theres a couple of old farm-boy fixes. If you put pepper or horse/cow manure in it it might work. People do this all the time on tractors areound home. I hope this makes sense the punch is killing me.
I had a hole about the size of my pinky nail in the bottom of mine. I tried fixing it with all the stuff on the market but nothing really worked. I finally drained it and pulled it and took it to a shop. They fixed it same day, tested it and painted it for $20. Had I known I would have done this first.

Don't waste your time with all the self sealer crap on the market...good for a trail fix but getting it fixed right is worth the piece of mind. Money well spent.

my 2 cents

If it was mine and the rad was original I would buy brand new from CCOT unless you can find a better price. Then, while it was out, I would replace the waterpump, thermostat, all hoses and all associated gaskets. You can do all of this yourself in a few hours. $500 or so for all of it. Option #2 is a bit of JB weld over the hole and hope for the best. The stop leak stuff is bad news. It can clog passages in the block.

Selly's Silicone 404 :)
If you're not having any other cooling issues, and the hole is near the top, then just use a two part epoxy like JB weld. I patched a small hole on mine 5 years ago and still no leak. Stay away from the additive type stop leaks.
Call and reference their internet sales. they were selling 4-row cruiser radiators for ~$150 about a month ago. They also have a 3-row so if you have a preference you'd have to tell them. some rad shops won't even touch them for service for less than $50 and if you replace it yourself that 25-35% of the total cost.

Thanks everyone for taking time to give me advice.
Greatly appreciated. I pulled out the Rad. and took it to the shop.
In one morning they repaired it, pressure tested, power flushed, and painted it
for $52 even with a guarantee. Glad I got it done right! Thanks again!

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