Freeze Plugs Redux

[D25_Owner]

I drove the D25 today for the first time with the new engine. It runs good, but three of the five freeze plugs are leaking. I installed several of these (1-5/8" concave discs) while the engine was on the stand. I removed a few and re-installed them just to check

how tight they were. I tested various dimples from small to large, deeper, wider etc. Ultimately, I installed all of them with the dimple size that seemed tightest, but I never had confidence in them, because they seemed too easy to pull out. I should have known better than to use them.

Moving on, I doubt I will be able to install another set with the engine in the car any better than I did on the stand, so I'm looking for an alternative. I read previous threads on the topic and there were a couple of mentions of Dorman 568-010 (metal with a spreader bolt). For lack of an alternative, I'm thinking of replacing all five with these. I used the rubber expansion plugs on a few projects years ago (SBC) and never had a problem with them. Has anyone had experience with these on the flathead 6s? What do you think would be better to use between the Dorman bolted plugs or rubber expanders?

I hope I only have to do this one more time!

Edited March 19, 2010 by D25_Owner

[Niel Hoback]

Maybe you could post a picture of one of your freeze plugs. Its important how you expand then to make them seal. A dent in the middle won't do it.

My best luck with them comes by using a half inch drive socket with a diameter about 3/8 smaller than the plug. Put a bead of permatex 2 around the edge of the hole before you set the plug into it. I put an old extension inside the socket so the flat side of the socket is against the plug. I hit it hard enough to flatten the plug which makes it spread out and seal tightly. That seems to work better for me than using the cup shaped plugs also.

I once had a rubber plug pop out of a 318 and it domped all the coolant immediately. I consider them an emergency only, limp-in quick fix to be replaced at the first opportunity.

[TodFitch]

Did you use any sealer around the edges when you installed the plugs?

I used Dorman 550-023 plugs (1 5/8 inch diameter) on my 1933 engine. I believe that would be the same size as needed on later engines.

[55 Fargo]

I drove the D25 today for the first time today with the new engine. It runs good, but three of the five freeze plugs are leaking. I installed several of these (1-5/8" concave discs) while the engine was on the stand. I removed a few and re-installed them just to check

how tight they were. I tested various dimples from small to large, some deeper, some more shallow. Ultimately, I installed all of them with the dimpled size that seemed tightest. But, I never had any confidence in them, I should have known better than to use them. Moving on, I doubt I will be able to install another set with the engine in the car any better than I did on the stand, so I'm looking for an alternative. I read previous threads on the topic and there were a couple of mentions of Dorman 568-010. For lack of an alternative I guess I'm thinking of replacing all five with these. I used the rubber expansion plugs on a few projects years ago (SBC) and never had a problem with them. Has anyone had experience the these on the flathead 6s? What do you think would be better to use between the Dorman bolted plugs or rubber expanders?

I hope I only have to do this one more time!

I suppose you could use the expandable plugs, if you so choose,or do what I did in-car, and to date have never had a leak, I simply used a sealant on my plugs, then set them with a very short brass rod(about 1 inch thick), seemed to work well........Fred PS the brass plugs are softer and may dimple set better

[D25_Owner]

I used Permatex 2 on them. I also used sockets (in varying sizes) as drifts.

I bought 12 plugs, installed seven them and pulled them out for the sole purpose of testing them. They all seemed loose to me.

Anyway, since I'm going to replace all five on the side of the block, with the engine in, something I can bolt seems a lot more appealing than swinging a hammer where there's so little room.

Edited March 19, 2010 by D25_Owner

[Jerry Roberts]

javascript:void(0); Here is a photo of the Dorman product installed in my engine . It has been in there for 2 years and no problems .

[Jerry Roberts]