Leaking antifreeze

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slk
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Leaking antifreeze

Post by slk »

Hey guys I have a leak somewhere on the top of the engine. I am assuming it is form the gasket on the top side of the water inlet. I am also assuming that there is a thermostat in that housing as well. When I look up parts all I see is a gasket with 3 holes. This one only has 2. I have included a pic. It seams to leak and fill up the sparkplug hole. It only seams to leak after you run it and park it for a while. I want to go on and replace the thermostat while I am in there. At least that is where I think it is leaking from. Also what procedure is it to fix. I looked in my manual and they say to remove some other elbow that has a gasket as well. That does not make sense to me to mess with that part if it is not leaking.

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just me
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Re: Leaking antifreeze

Post by just me »

Tighten all the hose clamps first. That's the usual culprit.
If it still leaks, then clean it thoroughly and dry it.
Spray it with a talc powder
The leak will be obvious very quickly.
(Head bolts, t-stat, bypass housing, water pump, etc.)
"It may be ugly, but at least it is slow!"
John Mc
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Re: Leaking antifreeze

Post by John Mc »

I had a leaking radiator that caused similar puddles in a couple of my sparkplug holes
1951 M37 "Brutus" w/Winch and 251 engine
NAM VET
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Re: Leaking antifreeze

Post by NAM VET »

a few months ago, had a similar leak on my carefully rebuilt engine. What I did was to remove the "elbow", and flatten the flange surfaces with a stone, removing any tiny burrs hindering a good seal to the cylinder head. Then very very carefully aligned the thermostat and gasket, with a tiny bit of Permatex sealant esp for water pumps, and snugged it down. did the same for the small part above the water pump. I also wire brushed the slightly corroded surface of the inlet for a better hose/clamp seal. All good, but later had a tiny leak at the small part on top of the water pump, and needed to slightly snug the bolts a tiny bit.

In summary, I suggest stoning all metal meeting surfaces, to reduce gasket sealing problems. Also, using a different hose clamp style, Pegasus Auto racing has full circumstance wider clamps. A simple problem but vexing to fix. Hal
Murf
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Re: Leaking antifreeze

Post by Murf »

After your mating surfaces are flat (hose connections as well) use Form-a-Gasket Type 3 Aviation from Permatex. The brown tacky stuff that gets on everything. It's readily available.
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