Freeze Plugs Question

[Eddie47]

Hey,
I have a 1972 C10 350, with leaking Freeze Plug under the motor mount on the drivers side.
What all do I have to take off to have the room to work.



Thanks
Eddie47

[passthebuck]

The easiest way would be to knock out the bad one & install one of those rubber freeze plugs that you tighten up the bolt on. They work & are easy driveway fixes....

[68gmsee]

I've done it before in a couple of ways. The first one I worked out with a large crew driver after driving a hole into it (rusted real bad) and then used a rubber one like passthebuck says.

The second one was a little harder and I also wanted to put an original looking one in. A buddy told me to just drive the old one into the engine and put the new one in.

I didn't like that idea so I had to drill a hole into it and then I pried it out with a long bar I made.

[truckdude239]

replace it with a new metal one i have seen the rubbers ones in my time in the auto field and they just don't last had a guy in the shop the other day with a leak turned out to be the rubber freeze plug leaking that he installed 2 weeks before

[Eddie47]

Originally Posted by truckdude239

replace it with a new metal one i have seen the rubbers ones in my time in the auto field and they just don't last had a guy in the shop the other day with a leak turned out to be the rubber freeze plug leaking that he installed 2 weeks before

I agree I used the rubber ones only one time and in a week had to do it over.
This one looks like it is not simple to change, so I only want to do it once and get it right the first time.

Eddie47

[brianthelion02]

Center freeze plug ,on a 350 hmmmmmm.It should have one under the motor mount and one further back on the block,if it has a third freeze plug then it must be a 400!!!!!!!If its the one under the motor they are easy i used a bar and pried against the motor mount and it went right in!!!!!!!

[Eddie47]

Originally Posted by brianthelion02

Center freeze plug ,on a 350 hmmmmmm.It should have one under the motor mount and one further back on the block,if it has a third freeze plug then it must be a 400!!!!!!!If its the one under the motor they are easy i used a bar and pried against the motor mount and it went right in!!!!!!!

It is a 350 and the plug is under the motor mount. I meant it was the center of motor, my mistake.
The getting out of the freeze plug is what I like to know what I need to move.

Eddie47

[Longhorn Man]

Its been a while since I've looked at a small block in these trucks so as far as how to manuver around all the stuff, I can't say anything.
However, a few things i have learned over the years...
If the plug rusted out, odds are, there's a BUNCH of rust in the water jacker.
If one rusted out, odds are, the rest are gonna go soon too.
Steel plugs rust, brass ones don't. (worth the extra money IMO, and I'm a cheap SOB)
Rubber plugs are like red tape for the broken tail light lens, it'll get you home, but it isn't a perminant fix.
Hammer the old one in with a screwdriver or a punch. Don't hit the center, it'll just rip. Hit the edge. Odds are, it'll just turn in the hole. Grab it with pliers or vice grips and pull it out. If it does fall in, reach in with needle nose pliers and remove it.
Stick your finger in there and feel around. if there's rust sludge in there, get the garden hose and spend a little time squirting it out...even better if you are gonna do them all. You'll be flat out amazed at how much crap is in there.
Grab a socket that fits in the plug... as big of one you can use.... maybe 15/16ths or so? (again, been a while since I messed with a small block) Put a short extention on it, preferably a cheap one you don't care about... use a hammer on the extention hooked to the socket, to drive the plug into place.
Some will tell you to use sealant on there... if you do this, they may not pop out if the coolant freezes, so I don't recomend it. If they still leak after replacement, then maybe you can glue them in, but that's a band aid fix for other problems.

[Eddie47]

[prg machine]

just a note: use a sealant on the new steel plug going back in.

[OLDIRON69]

The long block I put in my truck recently had the same freeze plug leaking from the get go. To get to this freeze plug you will have to (this is how we did it). Unbolted the shroud, used a cherry picker to raise the engine on the passenger side after we removed the tower and motor mount. Installed a new freeze plug, still leaked and that was with sealant, actually a varnish type stuff the machine shops use. The plug still leaked. There was a void in the area where the plug seals so I put a rubber plug in it and called the machine shop I got the motor from. They said they would repair it if I brought the motor to them, I told them I put a rubber plug in it and told them to make a note on their paper work so if the rubber plug started leaking again they would know this was already an issue. So far and 500 miles later still holding fine. We have ran the rubber plugs in skid loaders and fork lifts for 10,000+ hours and never had one leak..maybe just lucky I guess.

[Longhorn Man]

so, your machine shop is going to take care of it, but you'd rather drive around with a half ass repair that can pop out or leak with absolutly no warning?

[OLDIRON69]

I have never had one fail, so the awnser is "yes" for now. When I have time to take the truck to the machine shop and let them repair it (how they are going to do this with the motor in the truck I will never know).

[Eddie47]

Thanks for all your feedback. Kinda looks like it is the lift up the motor job o well no easy way out.

Have a good one.
Eddie47

[Sport/Truck]

I thought they were just called freeze plugs, but don’t really offer any protection against a cracked block?
s/t

[BCOWANWHEELS]

use permatex #1 hardening to install new plug, clean block with sand paper till its all shiney all the way around hole. use a socket same o.d as i,d of new freeze plug a install tool.

[Longhorn Man]

Originally Posted by Sport/Truck

I thought they were just called freeze plugs, but don’t really offer any protection against a cracked block?
s/t

In reality, the coolant CAN freeze and still crack the block, however, i have seen the plugs pop and save the engine more times than not.
Like I said before, glueing them in kinda defeats the whole concept.