A couple of weeks ago I was headed out to a local SDC meeting. It was a cool afternoon and I was looking forward to a “fun” drive. After the 500 mile round trip to Branson and back I was gaining confidence in the ’55 President State Sedan. I decided I did not need to glance at the temperature and oil pressure gages every minute or so.
About ½ mile from home I heard what sounded like something fell out of the car but I did not see anything in the road behind me so I blew it off and kept on driving. I saw what looked like oil smoke coming out the exhaust and knew that I had not seen that before and became a little concerned. A couple more miles down the road I looked at the temperature gage and the needle was at the top of the normal range.
That got my attention and I did a u-turn and headed back home. By the time I got the three miles back home the needle had pegged on the hot side and when I shut off the engine steam was rolling out from under the hood. The first freeze plug of my lifetime had popped out. I did a search of the forum and there were some outstanding threads on the subject.
The Dorman 1 1/2 inch expansion plug had been recommended. I ordered one up and got under the car to fix it. The freeze plug was the front one on the left side of the 259 V8. Of course it could not have been one of the rear two which were pretty easy to get to with the starter dropped. I loosened the crossover pipe and turned the wheels which allowed me to at least reach the hole with a 7/8 combination wrench.
A couple of the earlier posters to the freeze plug threads had mentioned the hex nut on the Dorman plug was pretty shallow. That proved to be the case. I did not have any metric wrenches that large but the 7/8 fit pretty well. I tried to hold the plug with the 7/8 wrench while tightening the small hex to expand the plug. There was no way I could keep the wrench from slipping off and therefore the plug turned in the hole and never did get very tight. It just fell out.
After studying the situation and a little prayer, I felt the problem was a combination of shallow hex and the 7/8 wrench. The wrench had a beveled area before it actually got to the teeth or whatever the 12 points are called. Te beveled area was allowing the teeth to barely get a hold on the hex nut. I had an older, cheaper 7/8 wrench which I ground down the beveled area on. It was able to get a better bite.
Some Permatex 2 was placed around the edge of the plug and this time I was able to hold it pretty good while tightening the smaller acorn hex. I was putting some pretty good pressure on the ½ socket and I think got it pretty tight in the hole (I hope). I drove the car a few miles this evening and at least it did not pop out.
I am now a little gun shy about driving the car. Maybe a few more trips will get me a little more relaxed. The problem I see is that all six freeze plugs were installed the same way. If one has popped out there is a possibility another one could also. I sure wish now I had read StudeRich’s suggestion to flatten the concave disks which I am sure would have maximized the compression between the plug and the block. I used a socket and hit it pretty hard with a 4 lb. sledge which created a depression in the plug but evidently not enough. At least next time I will be able to understand what is taking place a lot faster. I pulled the plugs and did a compression check on the left cylinders and there is no indication of a blown head gasket. The engine runs nicely so hopefully nothing was damaged.
Charlie D.
About ½ mile from home I heard what sounded like something fell out of the car but I did not see anything in the road behind me so I blew it off and kept on driving. I saw what looked like oil smoke coming out the exhaust and knew that I had not seen that before and became a little concerned. A couple more miles down the road I looked at the temperature gage and the needle was at the top of the normal range.
That got my attention and I did a u-turn and headed back home. By the time I got the three miles back home the needle had pegged on the hot side and when I shut off the engine steam was rolling out from under the hood. The first freeze plug of my lifetime had popped out. I did a search of the forum and there were some outstanding threads on the subject.
The Dorman 1 1/2 inch expansion plug had been recommended. I ordered one up and got under the car to fix it. The freeze plug was the front one on the left side of the 259 V8. Of course it could not have been one of the rear two which were pretty easy to get to with the starter dropped. I loosened the crossover pipe and turned the wheels which allowed me to at least reach the hole with a 7/8 combination wrench.
A couple of the earlier posters to the freeze plug threads had mentioned the hex nut on the Dorman plug was pretty shallow. That proved to be the case. I did not have any metric wrenches that large but the 7/8 fit pretty well. I tried to hold the plug with the 7/8 wrench while tightening the small hex to expand the plug. There was no way I could keep the wrench from slipping off and therefore the plug turned in the hole and never did get very tight. It just fell out.
After studying the situation and a little prayer, I felt the problem was a combination of shallow hex and the 7/8 wrench. The wrench had a beveled area before it actually got to the teeth or whatever the 12 points are called. Te beveled area was allowing the teeth to barely get a hold on the hex nut. I had an older, cheaper 7/8 wrench which I ground down the beveled area on. It was able to get a better bite.
Some Permatex 2 was placed around the edge of the plug and this time I was able to hold it pretty good while tightening the smaller acorn hex. I was putting some pretty good pressure on the ½ socket and I think got it pretty tight in the hole (I hope). I drove the car a few miles this evening and at least it did not pop out.
I am now a little gun shy about driving the car. Maybe a few more trips will get me a little more relaxed. The problem I see is that all six freeze plugs were installed the same way. If one has popped out there is a possibility another one could also. I sure wish now I had read StudeRich’s suggestion to flatten the concave disks which I am sure would have maximized the compression between the plug and the block. I used a socket and hit it pretty hard with a 4 lb. sledge which created a depression in the plug but evidently not enough. At least next time I will be able to understand what is taking place a lot faster. I pulled the plugs and did a compression check on the left cylinders and there is no indication of a blown head gasket. The engine runs nicely so hopefully nothing was damaged.
Charlie D.
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