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1938 Buick Special - should I pull the freeze plugs?


-Rich

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My '38 Special was lightly restored and overhauled about 35 years, and 12,000 miles, ago.

This past year, my exhaust manifold gasket started falling apart. What started out as a simple gasket replacement has now mushroomed into the dreaded "Well, as long as I've got it apart..." syndrome. cool.gif

After much reading on this forum and others, I'm trying to decide if, as long as I've got the manifolds off, should I pull the side freeze plugs and do any cleaning out? I know I won't be able to get at the rear plug, so I'm just looking at the 3 on the left side for now.

Here in Georgia, the summers are pretty warm. Last year, she never actually overheated (boiled over) on me, but there were a few times she got close. On normal drives (50-55mph and 90+ degrees), the temp gauge would read between 180 and 190. As soon as I'd hit a red light, or get caught in traffic, it'd would creep up closer and closer to 200+.

I'm going to pull the radiator and have it cleaned, and also check the water pump. But should I pull the freeze plugs, or not??

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Having owned three Buick Straight Eights and having worked in GM Dealerships I would say Yes. The cost is almost nothing since you are already there. Even if you were to find no crud you would have the piece of mind of knowing overheating troubles were caused by something else. Core plugs are easy to knock out and easy to replace. Also you will be sure that the ones in the engine are not almost rusted through and will blow out on you on a trip.

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Guest OLBUICKS

If you do be sure and get brass plugs.. I put some regular ones from a auto parts store in mine about five years ago and they only lasted about 2 years, and one of them had a pin hole rusted thru that fast.. Bob's has brass one,, get those

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Ok, y'all have pretty much confirmed my suspicions. I'll add freeze plugs to my next order from Bob's.

Mark Shaw - what's the best way to cut through the firewall? I haven't yet completely removed the firewall liner - still have the main wiring harness to deal with - so I'm not sure what I'll be looking at. I don't want to cut too big a hole/flap, but will obviously need enough room to work, etc.

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Your hole only needs to be 1/8" larger than the core plug.....provided the hole and the plug are centered. You don't need any working room. I cut my hole in my 53 with a sabre saw and used a balde about 5/8" long. This was two weeks after doing a complete engine overhaul. The machine shop guy didn't install the plug right and it leaked. I wasn't about to pull the engine and as it was just an old car at that time I used my saber saw.

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So this evening I took the advice of this Forum and pulled the 3 freeze plugs on the side. I was amazed at how much gunk was just sitting there, and came right out! If it's any indication, I'm going to have quite the mess when I pull the rear plug.

Hopefully my pictures will post, and y'all can see my next question. Given the amount of (corrosion? scaling?) that I plainly see, what's the best way to remove as much as possible, without causing any damage to the block? I've read the posts about caustic acids, and am not real comfortable with that. Do I just chip away what I can, and leave the rest? Thanks!

post-56588-143138049685_thumb.jpg

post-56588-143138049711_thumb.jpg

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Guest rusty1951

I used a pressure washer. I had removed the head and all the plugs and blasted top down and all the gunk came out of the plugs. I like water since it just will get everything wet.

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Guest OLBUICKS

I also used hi presser water.. remember most of you gunk will settle to the lower section at the plug in the pic... I cleaned my as good as I could, had the radiator recored,, it run cool now...

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