Engine Leaking Radiator fluid

[mcwinery]

I have a 1955 2nd series with original everything except the new headlights and air cleaner. Today I took it out for a ride and developed a leak below the manifold and below the carburetor. attached is a photo. I cleaned the round area so it can be better identified. What are my options? It is a difficult place to reach but possible to remove some parts and access it from below or above.

[nvrdone]

is that a v8 or a straight 6? its possible to replace that freeze plug, but if one is leaking others will start to leak in the future. I would recommend removing the engine & replacing all the freeze plugs

[mr48chev]

Freeze plug core plug or soft plug depending on what hood you live in but I'd agree that and the rest of them need to be changed as one of the others will probably leak before long.

That's a cup style so it isn't real difficult to change.

[dsraven]

this may start a few other issues if you have a system that is a little weak or corroded in spots, but what I would recommend is that you add some cooling system flush agent and follow the directions on the jug. usually it entails running the engine for 15-20 minutes and then dumping the whole cooling system. if you decide to flush with water directly after this be aware that you should be using hot water at this point to eliminate the chance of shocking the castings and causing cracks or warpage. at any rate, I would do a cooling system flush and then flush with water to get rid of as much debris and sediment as possible. when cool, remove the frost plugs and flush through those holes as well. disconnect the heater hoses and flush the core out in reverse flow, disconnect the rad hoses and do the same there. replace the frost plugs and thermostat (new OEM stat), now is also a great time to replace the water pump and check the belt, check all the hoses before reconnecting and then fill with mixed antifreeze/coolant. pressure test the system for leaks to ensure the heater core, water pump or rad didn't develop a leak after the flush. start it up after and run up to operating temp, checking and topping off the rad as you go.
to remove the frost plugs I use a dull cold chisel on one edge of the plug to get it started to push into the engine, it will usually start to hinge or pivot and at that point I put the chisel or prybar into the gap between the plug and the engine block and pry it outwards. to clean the frost plug holes I use a knotted wire brush on my die grinder but a drill also works fine. try not to nick the engine internally because it may cause some scale to come off the internal part and then that spot will become a "cold " spot when it is running. a little bit of slag or rust is like a layer of insulation so the area around the "bare" spot will conduct heat away faster than the scaled up area. when all cleaned up check the sealing surfaces of the block where the new plugs will seal. look for pits and anything else that will cause a leak. JB weld can be used to fill these but ensure the new surface is round and flat like the original would have been. when you sand down the JB weld use something that won't conform to a shape, not your finger, on the sandpaper. when all good coat the new frost plug with some aviation form a gasket on the sealing areas (it's that sticky brown stuff that never hardens. DO NOT USE SILICONE SEALER) and use a socket that fits inside the cup of the plug as a driver to install. hammer them in squarely, done.
some parts stores will sell a frost plug/oil gallery plug set but you can usually buy individual plugs as well, once you have the size you need figured out.do a check to see if the engine has frost plugs behind the flywheel or on the rear of the engine. you may not need to pull the engine to do this job, simply remove some accy that you will need to remove anyway no matter which way you go.

[mr48chev]

I've always coated the outside edge of that style of soft plug with #2 Permatex to help seal it.

It wouldn't be a bad idea to flush the cooling system before you replace the plugs. That way the inside of the water jackets will be reasonably clean when you put the new coolant in it.

It would be a good time to check over all the hoses and possibly replace the thermostat too. That way the cooling system is all up to snuff.

One thing though, if the radiator looks like it may have had leaks in the past that someone used a leak sealer on I wouldn't flush the cooling system except to flush it out with clear water when the engine is cold. I've done a cooling system flush on a couple of rigs that caused the block seal or radiator leak seal to fail and caused a leak. Daughter's old car evidently had a cracked head at one time and when we had the cooling system flushed it started leaking and I had to add block seal to it and it was still working good when she traded it off. I think I still see that old bugger running around the area once in a while. I had a later model Chev truck a few years ago that had more band aid fixes on it than the law allows. I ran some flush though it as it wasn't cooling too good and the radiator sprung leaks in about three places. Had to raid my buddy's radiator stash on that one and add one to his scrap pile. He sold me the truck so fair was fair.

[mcwinery]

Thanks DSRAVEN and MR48Chevy,
I may just end up using some JB weld for now. I have a plan in October to add power steering and may just wait until then to do everything mentioned above. I have all new hoses and radiator. Need to put a new muffler and piping in so it would be a good time to do everything at once. I will post a JBWeld picture and let everyone know how it turned out.

[dsraven]

in that case I would jb weld a complete round, like a washer with no hole, over top of the depressed center of the old frost plug. it has to hold back some pressure so a dab of jb weld over the hole may be easily blown off when hot under pressure. clean it up well with some sandpaper and stick a new middle on it. hope for the best. carry extra coolant.

[dsraven]

a rad cap with a lower pressure is also a thought.

[_Ogre]

Originally Posted by dsraven

a rad cap with a lower pressure is also a thought.

my thoughts exactly, just loosen the cap to run zero pressure
had a 63 chevy II that i ran with a loose cap for years

[nail pounder]

In my younger days I ran a couple of these in my old scout for years, maybe 8-10. Never had any issues. I agree with flushing the system first.

[mcwinery]

Thanks for all the suggestions.
I will post my pictures as I fix my problems

[dsraven]

I was going to suggest one of those as well. thanks nailpounder. they also may assist with the pitted hole in the block, if that is the case.not a long term fix because it defeats the purpose of having a frost plug to push out rather than crack the engine block. maybe your climate wouldn't matter?

[OrrieG]

Originally Posted by dsraven

because it defeats the purpose of having a frost plug to push out rather than crack the engine block. maybe your climate wouldn't matter?

I always thought the frost plug theory was a little bogus. I thought they were voids from the block casting process. I have never heard of one being pushed out when the block froze but have seen a few cracked blocks with them intact.

[tmoble]

What Orrie said. freeze plugs = bunchaBS

[Silveradobs]

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