Looking for some advice. Sprung a leak in the freeze plug on my 394 behind the oil filter. Tried to pop it out and it just fell apart. Center is pretty much gone but the rim is solidly in place.


Am I going to have to pull off the oil filter housing to get this out and back in? Any suggestions on how to break the freeze plug rim loose?


Thanks.

 

The last freeze plugs I removed where from my 52 GMC pickup. I had to punch a hole in the centre and rig up a 90 degree finger for the end of my slide hammer to pull it out. Was pretty easy since the motor was out.
I hope the pieces fell out of the block, you dont want those getting into the water pump.
You could use an old slot driver to try to bend the outer ring in until you can grab it with some vice grips to pull it out. Dont chip the engine casting!

Mark

 

Mine engine is in the car. Trying to keep it that way.

 

I'm not sure how much room you have on a 394. I've used a chisel and hammer to carefully tap at the lip of the freeze plug on one end into the block and grab the opposite that extrudes from the block with pliers and pull it all out. Again, careful not to wreck your block. I've also found once one freeze plug goes out the others aren't far behind. Did the center piece fall into the block?

 

no, pulled out the middle. Edge is just really locked in there. I am thinking I will need to remove the oil filter housing to get this out.

 

if you can pry sideways with a large screwdriver or tap it in a bit to loosen it first. or drive it all the way in, grab it and pry it out. i know, im not standing on my ear looking at it.

heh heh

 

I just looked at my 394 on the engine stand, i just rebuilt it. Yes, you will have to pull the oil filter housing to get it back in, maybe not out, but for sure to get it in.

 

I saw your post re the freeze plugs, one is going in my block just behind the starter motor.

Are there 4 or 6 freeze plugs in the bottom of the block? Can you tell me what size they are?


I know there are heaps more around the block but just want a quick fix with these for the time being.

Here it is hard to get a set local so I may be able to get some from another brand motor if you or anyone can tell me the sizes I am likely to be needing.


Thanks
John.

 

I pulled the oil filter housing on my 394. Especially so to install the new plug. For a quick fix, you may be able to use the expansion type. I don't recommend these, but that's your call. If you take the oil filter housing out, you may as well install the proper freeze plug. Go with brass plugs if you can. The driver side, you would want to remove the starter. If I remember correctly, Those are the only two things I had to remove to replace the 3 plugs on each side of the engine. I'm pretty sure there are two more at the rear of the block, but you need to remove the transmission to get to them.

 

On the 394, on the block, there are 3 on each side, they are 2 inches in diameter. On the heads, there are one on the back and one on the front on both. There are none in the back on the block.

 

Thank you very much gents, I will hunt some down for the weekend.

 

Saved by him: Thanks for clarifying no freeze plugs on the back of the block. When I removed my transmission to change the input pump seal, I thought I had seen two plugs just above the fly wheel area. The light wasn't the best at the time, nor my eyes for that matter. I thought these would come back to haunt me for not changing them when I was that far into it. Thanks again for the clarification.

 

The ones on the rear block are not sealing the water jacket, access to oil galley plugs are behind them.

 

My freeze plug that needs replacing is actually behind the oil filter, front 2 are fine. I'll check the 3 on the other side of the block when this one is done, nearly there. Just have to pull it out today. Gave the oil filter canister and housing a good clean since it was out. My, wasn't there some sludge in that canister!


I am replacing the plug with a brass one.

 

No wonder the freeze plug corroded, there was about 50 years of crud pilled up behind it at the bottom of the plug. Ate through the steel. All others good and one on other side was replaced probably when I bought the car. Gave the oil filter housing a clean up while off the engine, and threw the new front shocks I had kicking around the shed on for good measure.