gzvette61

My radiator has been leaking very slightly after running, dripping out through the drain petcock. I tried to tighten it, but the ears just turned on the shaft, so I couldn't tighten it. I got a replacement from Keen at Hershey, and got around to trying to replace it today. The ears came off the petcock totally when I tried to open it with a needle nose pliers. Thought it was going to be simple repair, but I can't get the old one off. There's white around the threads, corrosion maybe. It was probably installed by the previous owner about 10 yrs ago or so. I got a wrench on it, and leaned on it pretty good, but it wouldn't budge. I was scared of putting too much muscle into it, didn't want to damage the radiator. Any suggestions on how to get the old one off without radiator damage?

Fawndeuce

The extension tube from the bottom of the radiator is aluminum, someone probably installed a non aluminum petcock years ago and you have galvanic corrosion between the dissimilar metals.
I would try putting some penetrating oil on it for a few days and try again, but be sure to hold the pipe while loosening the petcock to not damage the rad.
Ultimately you may have change the pipe and petcock, but the new aluminum petcocks sold by the vendors are crap, go with a brass one, but use teflon or antisieze on the threads avoid galvanic corrosion in the future.



Paul

Frankie the Fink

Why even try to save it if the ears are busted off? Do the penetrating oil thing and then maybe some heat after a few days and get medieval with some vice grips to see if you can break the whole thing loose and replace it. If you want to Bubba it you could pack it full of JB Weld and then the bottom radiator hose is your drain point. Many radiators don't even have petcocks.

I would never use needle nose pliers on petcocks. Regular pliers with wide jaws held parallel to the ears and turned carefully work best.

Redbird

Key to petcocks is that most people over tighten them. Finger tight works fine for me, just like spin-on oil filters.

Frankie the Fink

Errrr....you better go a little more than finger tight on oil filters my friend.
A petcock only has to withstand about 13psi...an oil filter 60+ in some cases...

wmf62

he can probably benchpress 350 with his fingertips....
Bill

gzvette61

I used the needle nose to try to get a grip on the edge of the tube after the ears came loose and just spun around the tube. The plan was to open the valve and drain it to change the petcock. Then the plan became removing the petcock to drain it.

It will be the weekend before I can get back to it, so I'll put on some penetrating oil tonight and again after a day or so and then try again with my nifty new Harbor Freight heat gun. I thought about the JB weld, but thought I'd try to do it right first, especially since I already had the part.

John S 1961

start with removing the radiator, then repair properly, or just plug the drain hole