Technical Radiator Cap PSI - Now Plugged Radiator

I filled it with hardware store vinegar, 5% acidity it says, overnight, washed it out this morning. Did come out milky, and now water poured in the inlet does come out the bottom but pretty good still got lots of white crud from what I can see inside. Might fill it again but don't want to hurt the metal, which it doesn't appear to be doing. Meanwhile going to call around next week.

 

I drained and filled my tractor with pure vinegar and used it for about 3 weeks. It takes me about 4 hours a week to mow. Drained and flushed, no damage. Lots of black and brown goop and big chunks. Runs cool now.

 

Sounds good. I just filled the radiator again with vinegar. Also poured a bucket of water down the thermostat hole, ran right out the lower radiator hose. Means at least it's going through the heads and into the block, I think..

 

Put a chunk of the crud I dug out of the manifold in vinegar last night. This morning, no change. Put the heat to it, still hard as a rock. Leaving in the soak. Hmm.

Will be taking the radiator to a couple of shops this week for opinions.

 

A friend had a radiator shop for 40 years. He says you can block off 10% of tubes and it won't effect the cooling. So don't let them tell you the damaged tubes make it junk, unless it's worse then your pictures show.

 

Is it possible that crud is someone's attempt to repair the cooling system with a "seal in a can" type of product from an earlier owner?
As some earlier comments, I think I might be tempted to pull the engine and get that crap outta there.

 

I think if it were me, I’d opt for the cheapest dang Far East radiator I could find that would fit in the space, hear me out. Now think of the radiator as a sacrificial piece. Put it in and get to mixing or buying your favorite block/radiator flush, pull the thermostat and get after it in your driveway and watch the temp.
Drain and re flush here and there.
You know what’s going to happen if you go down the “pull the engine” rabbit hole.
I’d rather trash a few 100 dollar radiators over a few weeks time trying to get things cleaned out, than a high dollar brass/copper radiator once.

Hey, probably get some money back at the recycle place for the dead radiators you bring in

 

Thanks guys. As I mentioned, I poured water down the thermostat hole and it ran out the lower radiator hose as fast as I poured it in. I don't remember the details of the coolant passages but I think it's going through the heads, past the head gasket, into the block and out the pump. I wouldn't pull the engine unless it still overheated with a good radiator. And yes, a cheap temp or test radiator isn't a bad idea.

A friend mentioned coolant filters made by Gano, look it up if you don't know. Keeps anything out from block to radiator.

Yes this crud could be somebody's leak sealer, or oatmeal or whatever.

 

I think he meant CLR.

 

THATS IT!

 

Don't I even get partial credit?

 

CLR is a good idea, I was thinking GIN. I'll get some today and put a chunk in it.

The area under the thermostat housing was plugged solid (photo above), but when that was out the passages in the manifold to the heads were clear. Also the thermostat housing is clear. Seems odd how that happened, can't think of an explanation. There was no thermostat, was removed prior to '74 at least, along with the radiator repair. Thought maybe it actually WAS the corroded remains of the thermostat but no evidence of that.

Removing a freeze plug or two would be an easy way to look into the block.

 

Still curious to know what that crud is? And how far-reaching. Pulling the freeze plugs is a good idea. Also a new cheap "test" radiator. Doesn't look like it's ready to dissolve easily?

 

"No thermostat" is sometimes a "tell". Lots of folks don't want to run antifreeze (coolant) because they think it isn't necessary, but without corrosion inhibitors in the cooling system there's gonna be trouble.

A lot of engine blocks have those square pipe thread fittings external to the coolant passages, usually just above the oil pan line somewhere. Get something snaked in there, a coat hanger or something, to clean out sludge and sediment scale. If you can get them removed anyway.

 

Back in the day old manuals use to suggest you run a caustic soda mixture in the system...This would be okay as long as there isn't any aluminum in the system....

 

Just read an article on another site that had what sounds to be a similar issue. They dissolved the crud just by adding more antifreeze. They also discussed the issues of two different incompatible brands of antifreeze? Try putting that rock in some ant-freeze?

 

Looks like calcium to me, from hard water.

 

Funny you should mention that.. I had a look inside the tea kettle, which uses our well water, lots of solid white stuff stuck to it. The property where this car was stored was also on well water I would think.

 

Thanks guys.

Well todays episode of The Plugged Radiator is interesting. I drained the vinnegar after a 24 hour soak and brought it to Merv's Radiator in Petaluma. What a refreshing old school shop, getting to be rarity around here. Old radiator everywhere, not even sure I saw a modern one in the place. Clint, who runs it now, also an old school craftsman, spent over half an hour educating me on my options. He looked at a chunk of the crap and was miffed, thought maybe aluminum from the manifold, that's scary but it seemed solid under the gunk.

Clink explained the difference between my old honeycomb core and modern cores (don't know what they are called). He says there is a place that still makes the honeycomb cores, and he could re-use my old tanks, giving me an original radiator or as close as one can get. Much harder to solder than using a new type core with my old tanks, which have the advantages of being able to be rodded out and more rows can be installed for increased cooling. Cost about the same either way 900-1,100. We talked about my engine and he also stressed not installing a new radiator if there is remaining junk in the block. He has a gun that blows air and water at the same time he uses to flush engines, said it really works well. Clint also said the only complete new radiator he would trust is a DeWitt, which also runs a grand or more.

So I left with my radiator, until I get a little further along. Next stop was for some CLR, then back home. I have a chunk soaking now. I then put the garden hose to the radiator, water passes through easily now. I think the plan might be to stick it back in, leave the top hose off, fire it up and see how much water comes out. If it does circulate maybe put some in to clean and dissolve.

Thanks for tuning in.

 

Special bonus coverage of today's events. I ran the lower hose out to a funnel, filled and fired it up. Comes out the top hose pretty well, not like a fire hose, about like a garden hose with no nozzle. I'm guessing there is a spec for how much water circulates normally.

 

And.. I mentioned the Gano filters, like this. Which reminded me of the drain screens I recently put in my sink drain. Went back to Dollar Tree, sure enough, two for a buck. Something to consider.

 

It looks like you are making progress, hopefully you can get the old rad working okay and save a thousand bucks.

I agree the hard white chunks may be aluminum (oxide/hydroxide). Aluminum can form a lot of corrosion byproducts if left wet for many years.

So long as the vinegar cleaning solution is mostly white you are probably okay, once it starts to become green or blue be careful, it means it's starting to dissolve the brass/copper of the rad.

 

Just a thought, the same water runs through your heater core.

 

While you’re messing with the cooling system, go underneath and pull the block water jacket drain plugs. There’s one 1/4” pipe plug on each side in the middle about 1” above the pan rail. A lot of old Chevys had petcocks for draining. After all these years they won’t be easy to remove but you need to get them out and poke around with a small screwdriver or something so you can drain the bottom of the block.
I hate to say it but I would bet that your intake manifold has some significant corrosion damage in the areas where the water touches it. If it doesn’t leak I wouldn’t worry about it until you decide to tear into the engine but watch carefully for leaks and watch the oil for signs of internal leakage.

 

Pull it out rod it out put it back, a radiator shop will charge about $100 to rod it out.

 

I think it’s been awhile since you have had that done John.

 

Clint at Merv's Radiator told me honeycomb cores can't be rodded out.

Good idea. I put it on the list. Starter is beginning to give me trouble so I'll be under there for that.

Yeah, that occurred to me too. So today I popped the hoses off, was able to blow through the core, a bit of good news. I bypassed it for now.

This morning I put the old radiator back in, put the gallon of vinegar in and the rest water. Went to town and back, only 200 when I got back, went up to 220 when I shut it off (mechanical gauge). My flathead does that too, I guess the water around the sender gets hotter from not circulating? Anyway it's and improvement. After it cooled off some I drained it, here's what it looks like.

Also pulled the thermostat housing off again today and scraped around inside the manifold. Doesn't appear badly corroded. Here's a better photo of the junk that was in there. I suppose I could have it analysed? The vinegar test is finally breaking down the sample, the CLR (white cup) not much yet.

 

Corvette radiators are not honeycomb here's a real example for sale. I put "56 Corvette radiator" and this one came up for under $300

 

Right, they are not honeycomb. They can be rodded out, had one done about 2 years ago for about $100. They will fix the top tank leak too as they have to take it off to do it.