free frozen flare nut at radiator?

('99 Cavalier, auto, 4 cyl)

I have a leaking transmission coolant line, and the flare nut where that goes into the radiator is pretty corroded and frozen. The transmission end came off OK, with just a touch of heat. The problem is, the radiator has a plastic resevoir. So, ...

- Has anyone every (successfully) used heat there? It seems like a bad idea, but I thought I'd ask.

- How much torque can you put on that nut? (Like, 'not a lot', or 'go to town'.) I'm picturing the radiator fitting breaking loose from the plastic, and then needing to get a new radiator.

- Any other ideas?

TIA, George

Reply to
George
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Are you replacing the line? Isn't there a flare seat that screws into the radiator and then a flare nut that actually screws into that? I would leave the flare seat in the radiator and then use a backup wrench on it, then put your flare wrench on the flare nut and squeeze the two together with one hand (that way no torque or bending force gets transmitted to the radiator.) If you're replacing the line completely, just cut it off and slip a 6 point box wrench on it rather than a flare wrench. If you're trying to save it, use vice-grips to hold the end of the flare wrench shut.

Where is the line leaking? If it's not at the fitting, and you are trying to avoid an expensive repair, it may be easier to cut out the damaged section of line and splice in a short piece of hose.

WARNING:

you MUST use transmission cooler line for this. Fuel line will not work. I have personal experience with this, the end result was a car flambe and a slipping trans after the fuel line burst and dumped trans fluid on the downpipe (I didn't install the fuel line, just didn't identify and replace it until after it'd burst.) For safety, I would probably take a double flare tool and form a small "bubble" in each cut off end, and also make sure you use the high pressure style clamps.

good luck

nate

Reply to
Nate Nagel

I have used a product called "Kroil" as a penetrating oil. It works better than the stuff you find at most auto stores. Find them on the net, I think

Reply to
jfacquisto

I've drowned it in PB Blaster, which has worked in other places. (Frozen bolts around the gas tank, in particular.) In this case, I don't think it's penetrating the threads - it's like there's almost a glaze on them. Wire brushing hasn't helped a lot, but access is difficult.

G
Reply to
George

PB Blaster is pretty good; probably the best stuff you're likely to find at your FLAPS. I have used Kroil and Wuerth Rost Off with better success, but those are more expensive and likely mail order only. I think the Wuerth product is probably the best I've ever used, with Kroil a close second.

nate

Reply to
N8N

Well, I got it out. I made a heat shield out of some old sheet metal, and then applied (not a lot of) heat (propane torch), and a little more force using a breaker bar.

Thanks to all who replied.

G
Reply to
George

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