Freeze Plug Replacement

In lieu of buying a new exhaust manifold ($1800), I'm thinking of just replacing the freeze plus as they seem to be the weakest link in the raw water line. I took both end caps off yesterday to replace the exhaust elbow, and the other side (raw water) had plenty of rust flakes and grunge built up, causing the engine to overheat. I cleaned this out but am considering the freeze plugs replacements as extra caution. Appreciate all thoughts.

Mike

i would think about putting brass plugs back in if i were you

Jerry: That's a good idea; is removal of the old ones difficult? Thanks.

Generally they come out easier if the part is on the bench. You can use a socket to knock it in. I have a socket that matches the outside diameter of the plug to remove and install them. I agree that brass is the way to go. There are also various tools on the market for these.

Something you want to think about when replacing soft plugs is that you don't want to leave the old one in the block disrupting water flow. The best way I've found to knock out and then take out the old plugs, is to use a smallish drift punch on one side of the bottom of the plug, not the edge of the plug, to turn the plug in the bore. Then a pair of waterpump pliers or vise grips can grab the edge, which is sticking out of the hole, and pull out the old plug.

A little Permatex #2 on the new plug, and a socket or hunk of steel across the edges of the plug will allow you to knock in the new one. I like the hunk of steel method best as it allows me to make the new plug square in the hole and flush with the other surface.

Ken

I don't know how quickly they get eaten up, but if these are on the raw water side, you may want to use a bronze softplug if available. *Would be preferable to brass, as there is zink in brass.

Removal: Drill 3/8 hole in center and pry out with large screwdriver. Alternatively drive a 3/8 cold chisel*through center and pry out. Clean OD of hole to assure good seal.

Install: If*the slightly domed flat plugs: Set in place with dome out. Drive down with socket OD just smaller than plug. Set in place by thumping center of dome solidly to "flatten" dome and expand OD. If the deeper plug with rolled edge flange,*set in place with rolled flange out,*drive in with socket until rolled flange flush with surface of casting, In either type*light coating of*non hardening Permatex on OD is a good idea.

Bill

Thanks to all for the info.
Mike

If the old steel plugs lasted for 18 years perhaps that indicates the original material was an excellent choice by the manufacturer.

I hadn't thought of it that way Rick, but you're probably right. The exhaust manifold is a pretty thick casting, and seems to me that the steel plugs might be the weak link in the chain. There's a lot of rust in there and my guess is that the plugs are getting pretty thin, hence the idea to replace them. This may be overkill, and might possibly cause harm to the manifold when I attempt to pry them out. What do you think.
Mike

I did't mean to suggest retaining the old plugs. If you found the manifold full of rust and deposits then removing them to aid in cleaning is not a bad idea. I just meant that you don't have to replace them with a different material.

Bought steel ones this afternoon. Appreciate the comments.

Good choice.