Posted by Matt Wilson [172.69.68.174] on Friday, April 24, 2020 at 21:27:05 :
Hi Dave,
I saw your post on the last forum about freeze plugs popping out. I had that happen after my machinist installed new ones. It almost ruined my engine. You should be aware that there is one plug behind the timing chain cover, on the front of the engine. I know it's a pain to replace that one, but you might think about doing it (or getting the machinist to do it). If that one pops out, the coolant will mix with the oil and probably do damage to the engine. There is also at least one on the back of the engine. Some engines have two freeze plugs, and I believe they all have a plug behind the camshaft, which doesn't go into the coolant jacket. In other words, some engines have three plugs on the back and others have two on the backside, but one of those is for the cam area, not the coolant jacket, so that leaves either one or two coolant plugs. I dropped the transmission in my truck and replaced the one(s) on the rear with the engine installed in the truck. I also pulled the front clip off the truck and replaced the one that I mentioned is behind the timing cover. I got lazy and didn't replace all the ones on the left side of the engine, and just installed the expandable rubber types in those holes. They worked fine.
Good luck and let us know if you have any more questions.
By the way, I'm surprised Vaughn advised against using brass plugs. There are quite a few guys over on the P15-D24 forum who use brass plugs in their engines, and they prefer them over steel, saying the steel ones eventually rust out (although that's probably after 40 years). Some of these guys have rebuilt many of these engines and say they've never had an issue. Most of them use sealant such as Indian Head or even JB Weld, although as Steve Kaegi said, you may be able to go without sealant if the bores in the block and clean and free of rust pitting. Personally, I used sealant on mine.
Good luck!
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