Freeze plug is leaking...

[Dannys64]

Just wanna say first that stangnet ROCKS! plenty of awesome info and ideas!

I have a 1964 260 mustang and I noticed a freeze plug was leaking on the back/right side of the block when I was replacing the oil pan gasket. I have never changed a freeze plug before and I can't find anything in the four automotive manuals I have on freeze plugs. Can anyone offer some tips or trade secrets on the subject?

 

[88 Fox GT]

Welcome to StangNet! Your right, it's a great place.

Anyway, I have never really tried changing freeze plugs while the engine is in the car. But with engines out of the car, I would take a hammer and straight screwdriver and either tap the sides in and pry them out or punch a hole in the middle of them and pull them out like that. As long as your careful, you shouldn't damage the block. I'm really not sure if there is a special tool or "proper" way to do this, but that's how I do it.

When you put the new one in, you want to take a block of wood or anything larger than the plug to pound it in perfectly straight so it doesn't leak again. Good luck!

 

[HistoricMustang]

This is one of those six pack jobs. First a quick story about freeze plugs and heart attacks.

After the last rebuild I was doing the usual carb adjusting and took her up to about 4000 RPM's. As you know you are usually only a few inches from the motor when this is done. Just as she was getting a very nice song going the left rear freeze blew out of the back of the motor and I just about had the big one right there in the shop. It turns out that I had used the marine grade freeze plugs in the last rebuild and the engine builder had cleaned the heads using the "vat" process - dipping and cleaning. This is not good for marine plugs and off course he had failed to replace them. They became week and blew so be careful.

I think you have two challenges. First getting the leaking plug out and then even worse getting the new plug in without pulling the head. Do this, get the old plug out and then for a replacement get the type that you can put in with a wrench. You insert it and tighten down a bolt which expands and makes a seal. This is exactly what I did in the above story and actually ran a full race weekend without any problems as I did not have time to take the heads off the car.

Good Luck,
HistoricMustang
www.historicmustang.com