Rubber expansion freeze plug
- Thread starter mbaker
- Start date
We had old engines from years ago, mostly ford 302, 351, 390, when the frost plug rusted through someone put in those rubber types and they were in there for years! They work the same way as a block heater instead of a plain expansion plug, friend of mine wound up with four block heaters in his Cougar, it didn't have to be plugged in very long in winter to start, he put a block heater in when an expansion plug gave out, lol.
I prefer the metal ones but wouldn't hesitate using a rubber one if access was limited. Around six years back, I had a weeper on a Ford 3.8. Access was poor even for removal. I poured in Bars Leak and the leak was sealed and hasn't weeped a drop since , even after flushing out the Bars a couple years back.
I thought about that too, but didn’t want to plug up anything else. I had trouble with a Buick a few years ago and tried the GM cooling system tablets. Plugged up one side of the heater core and passenger never got hot air. Was able to flush it out though. Maybe Liquid bars won’t affect it that much.
GM tablets ARE Bar's Leak.
The Bars which I used had no pellits, so no clogging took place.
I bought a 350 Chevy Caprice with about 150,000 miles and at least two weeping freeze plugs in the block. They were a bear to get out and would have been impossible to replace without pulling the engine. I replaced them with rubber expansion plugs and drove it for another 50,000.
Still debating on whether I want to try the bars leak in it. It’s pretty slow, maybe a teaspoon or 2 over night that ends up in the floor. But it is on the front of the cylinder head so I think if we move the AV compressor we can get to it and either replace or stick an expansion plug in it. I know others may be in their way out but one thing at a time right now. It was my grandpa’s truck and he is gifting to my son so at the moment he is just interested in being able to drive it for the time being and shake it out since it really hasn’t been driven for several years.
I kept a rubber one in my glove box for my older mustang. I had put a new block / engine in it and it kept spitting one particular plug out, so instead of being stranded at the track every time I’d slip the rubber one in it and I was good to get home and get it somewhere I could replace it.
I always thought of the rubber ones as temporary personally.
I always thought of the rubber ones as temporary personally.
