VCCA Home Forums TECHNICAL - 1945 AND NEWER 1965-1970 What tool for radiator pepcock?

For the first time, I needed to drain the radiator on my 1966 327. The petcock is in a close position and I can't get leverage on the "wings" sufficiently to turn it. So I used pliers, and a crescent wrench.

The bad news is that when I tried to tighten it back up, the "wing nut" type lever, broke free from the screw. So now it's just spinning on the screw shaft.

My question is: Is there a tool, or a good technique that I can use to loosen and tighten the petcock on the radiator? I've had this issue before with other years (eg. 1931) but always managed to get it loose with pliers. On my 327, it's a tougher situation.

I'm thinking of a type of socket wrench that I could use to turn it with. Maybe I could make one out of wood?

---Bill

If it takes that much "torque" to seat then chances are it's time to replace it. Possibly the wing could be soldered to the shaft or if not for show replaced with a better quality petcock. If you want to adapt a socket to fit maybe a 1/4" socket with slots cut out to fit would work. Shouldn't cost more than a buck at a flea market.

needle nose vice grips. mike

That's funny, because I used needle-nose pliers to turn it. I have a set of B-I-G needle-nose pliers.

So -- new info. I purchased a new petcock at NAPA today - but it was brass. Same size, etc.

My original one is aluminum (as is the radiator)... I have a friend who says that I shouldn't mix metals. ???

Now... I didn't get a picture yet, but I did "make" a new tool tonight to loosen, and tighten, the radiator petcocks. If it works, I'll post it here.

I think it depends on the metals. Aluminum and steel I know can be a problem, but not sure of the brass. Maybe our "resident" cooling system engineer will "Chip" in some comments. Does the brass fitting have a rubber seal? Brass will provide a good seat, but again will require some pressure to seat. With an aluminum radiator you will need to be careful not to strip out the threads.

You might want to put some penetrating oil on the threads to help ease the petcock out without further damage.

I recently used PB Blaster on a the threads of a stubborn drain pipe in my house that hadn't turned since 1948. It didn't budge even with a two foot cheater bar on the pipe wrench!

After spraying the threads and banging on the pipe a little (I think vibrations from the banging help the oil to work into the threads), I was able to unscrew the pipe.

Cheers, Dean

I know as an electrician for over 35 years the the big NO NO is mixing copper and aluminum at any termination point. We were told it was "a reaction caused by dissimilar metals" It takes awhile for the problems to develop but when they did it was real bad. Again that is for electrical installations where the electrons are forced to flow and the conections are exposed to oxygen. Brass is made from a mixture of copper and zinc. Does it change the properties when combined with the zinc? I don't know, but if it were me I would check into it real good.

I have a radiator pepcock tool that you place over the "wing", it has a six point head and you can use an open end , six point box wrench or socket to open it. I have had it for years don't know if they are still available.