Truck Radiator Leak - HELP

I've just discovered a radiator leak in my 97 GMC 1/2 ton in the oddest place. It appears to be leaking where the transmission line makes a connection at the top drivers side of the radiator. The nut looks like some sort of spanner type nut and I thought I'd try to get some pointers here before doing anything to tighten the nut (so as not to make the vehicle immediately not-drivable).

Take a look at this pic if you would...

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Right between the nut and the radiator appears to be where this small but noticable leak is.

Any advice is greatly appreciated.

TIA, John

Reply to
jcage
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that appears to be a plastic tank; the only way you're going to stop the leak by tightening something is if it's between the flare nut and its seat. Use a backup wrench on the fitting on the radiator. If the leak is where you think it is, I'm not aware of a good way to fix it.

If you plan to keep this truck "forever" I will make a suggestion, which you can use or not at your discretion - if the plastic tank is cracked under that fitting, it would seem that that is a fatigue failure and what might be advisable is to cut out a short section of the supply and return hard lines to the trans and splice in a short section of hose, to better isolate the radiator from the movement/ vibration of the engine/trans. The thing is, this also introduces ANOTHER potential point of failure, so... you pays your money and you takes your chances. If you were to do this, you'd want to definitely make sure that you use transmission cooler hose, not any other kind, and proper high pressure clamps. Also I'd recommend taking your flaring tool and putting a little "bubble" on the cut ends of the hard line to act as a hose barb; you can do this by just starting a double flare and not finishing it - use the little anvil, but only tighten the screw down about halfway.

nate

Reply to
N8N

Those original plastic/aluminum rads and heater cores are not normally considered repairable.

The correct fix is to remove the rad and take it into a rad shop for assesment. It may be a minor seal that let go or it may be a cracked plastic tank. The tanks are replaceable, but the aluminum crimps that hold is on are very likely to crack off ( rad is now useless). Check around and get prices on having a new rad made up from copper/brass.

I did on an old chev I had and it was cheaper and faster than attempting a repair or replacement of the plastic/aluminum rad.

P
Reply to
cselby

there are also direct replacement all-aluminum radiators available, e.g.:

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that one is for an AT but without engine oil cooler, I just picked that as the most likely combo.

nate

Reply to
N8N

Leaked in the same spot on mine. Turned out to be a crack under the nut. New Radiator.

Cheers

Reply to
Martin Riddle

| > Take a look at this pic if you would... | >

| >

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| >

| > Right between the nut and the radiator appears to be where this small | > but noticable leak is. | >

| > Any advice is greatly appreciated. | >

| > TIA, | > John |

Those plastic tanks are replacable. You can buy them from any AC-Delco parts distributor or dealer. They aren't well stocked, but are available buy special order. They are stocked at the G.M. warehouse in Fort Worth, Tx.

The replacement tank comes with new seals and everything you need to R & R the tank.

A replacement plastic tank is about $45.00 and a radiator shop will install it for a nominal fee.

Reply to
Steve

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