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| | | Forums66 Topics128,159 Posts1,057,037 Members48,460 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jan 2015 Posts: 914 'Bolter | | 'Bolter Joined: Jan 2015 Posts: 914 | As the title asks are there any old time ingredients to put in the radiator to help flush out the radiator and the water jackets in the block? | | | | | Joined: Mar 2010 Posts: 10,305 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,305 | Only real way to remove the 60 years of petrified dinosaur dung is to remove the head, all freeze plugs, and water pump and manually dig at the crud from many angles. Once the big chunks are removed, a steam jenny works great for the rest of the job. It is my opinion that if you do anything less than this, you are: a)kidding yourself, and b)if you don't take it apart, you are not going to know how badly clogged your water jacket actually is. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: May 2006 Posts: 423 'Bolter | | 'Bolter Joined: May 2006 Posts: 423 | I hate to seem to disagree with anyone named Carl, but you might be able to do a fair job of flushing the system without such a compete tear-down. Keep in mind that dinosaur dung settles to the bottom of the block and even towards the back of the block - away from the radiator. You will come a long way by removing the rear pet cock down under the throttle linkage and steering shaft.
Most of those old engines will be so plugged up that nothing will run from the pet cock hole even with the spigot removed. So you need to go in with a piece of wire, like clothes hanger wire, and dig around in that pet cock hole until you get the primordial muck to run out. Keep the water running while you dig until the water runs clear. Then pull the freeze plugs and continue the process.
If after all this you decide that Carl with "C" was right, then every other part of the engine is probably in rough shape as well, and you might as well tear it down.
Have a great time! Karl It may not be the easy way, but it is the Cowboy Way - Ranger Doug Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri 1953 Chevy 3100 1960 Volvo PV 544 1941 Chevrolet Special Deluxe | | | | | Joined: Sep 2001 Posts: 29,270 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,270 | 32vld,
Is you engine on or off the truck?
If it is off the truck do as C-Carl suggests.
If it is on the truck, you can try what K-Karl suggests.
My experience is that an old block gets completely clogged up at the rear. As Carl (C) posted, it takes a lot of work to clean out the rear of the block (side to side, top to bottom). Cleaning out that entire interior area will have a significant positive impact on engine cooling.
Regarding chemicals: they are nice in cleaning a cooling system, but they will not clear/touch a heavily clogged block. | | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Try searching old post, I think Professor Jerry has answered this one about 50 times. Interesting thing about Jerry's posts, is that he has about half a dozen different ways to do just about everything. After digging around in that rear drain for 45 minutes with no luck, I just grabbed one of those air nozzles with a conical rubber tip, to get a good seal and hit it with about 80 psi. Let it flow, then hit it again 3-4 times.
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: Aug 2013 Posts: 568 Shop Shark | | Shop Shark Joined: Aug 2013 Posts: 568 | I've used tide laundry detergent in the powder form. Run it for a while at operating temp and flush away, takes a few tries but worked really well. All sorts of crud cames out. Then I blast it with the air nozzle.
Last edited by Hollow65; 05/30/2015 11:41 PM.
I can explain it to you, I can't understand it for you.
| | | | | Joined: Jan 2014 Posts: 3,690 'Bolter | | 'Bolter Joined: Jan 2014 Posts: 3,690 | Do a search of the archives. Someone mentioned having success with a bucket of CLR running some kind of circuit with a sump pump.
1951 3100
| | | | | Joined: Jul 2008 Posts: 1,321 'Bolter | | 'Bolter Joined: Jul 2008 Posts: 1,321 | Stick with a commercial product and save youself possible problems. Suggestions: Permatex 80030 Heavy Duty Radiator Cleaner, 1 quart BlueDevil Radiator Flush - 32 Ounce (00204) Thoro Flush INDUSTRIAL-STRENGTH RADIATOR AND ENGINE CLEANER Bar's Super Radiator Flush I have had great success using these products. "Keep your cool" Harold
Harold Is a restoration ever finished? | | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Think it was CASO out west that setup a loop where he could circulate a flush through the system overnight. Pretty good idea, and would be pretty simple to do if you had a big pan or bucket and any small pump, just let the drain spill into the bucket, put the pump in the bucket and run a hose up to the thermostat housing (with thermo out). Kind of like a parts washer setup.
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: Jan 2015 Posts: 914 'Bolter | | 'Bolter Joined: Jan 2015 Posts: 914 | I hate to seem to disagree with anyone named Carl, but you might be able to do a fair job of flushing the system without such a compete tear-down. Keep in mind that dinosaur dung settles to the bottom of the block and even towards the back of the block - away from the radiator. You will come a long way by removing the rear pet cock down under the throttle linkage and steering shaft.
Most of those old engines will be so plugged up that nothing will run from the pet cock hole even with the spigot removed. So you need to go in with a piece of wire, like clothes hanger wire, and dig around in that pet cock hole until you get the primordial muck to run out. Keep the water running while you dig until the water runs clear. Then pull the freeze plugs and continue the process.
If after all this you decide that Carl with "C" was right, then every other part of the engine is probably in rough shape as well, and you might as well tear it down.
Have a great time! Karl Well I had removed the drain cock from the left rear of the block. I probed around a little sludge came out. Then with my son we took out the thermostat and put the upper hose back on. Then with the radiator cap on my son applied air pressure to the over flow tube while I re-probed the drain cock hole. A little at a time more would start to flow. As it appeared as the dam would burst I told my son to stop the compressed air but alas the dam burst. Oh the humanity. I had to clean my sun glasses off. I had bought a bottle of prestone radiator flush. Though I wanted to drain out as much stuff before I used it. So when I get the time I will use the prestone. Thanks to all that applied. And I like that Tide Detergent idea. | | | | | Joined: Feb 2004 Posts: 29,871 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,871 | On the really badly gunked-up ones when I worked at a sand, gravel, and concrete business, I've actually used the same Muratic Acid we used to clean bricks and other masonry jobs. Dump 3-4 ounces in the radiator, top off with water, and run it until the engine temp comes up. Drain, flush with clear water, and dump a couple of boxes of baking soda into the final rinse to neutralize the remaining acid. For grease/oil contamination, flush with a good dose of powdered Trisodium Phosphate added to the water (concrete cleaner). All these chemicals are used in very weak solution in most of the commercial cooling system cleaners- - - -just use the real stuff in a very heavy dose to clean out the bad contaminants! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Nov 2010 Posts: 1,159 Shop Shark | | Shop Shark Joined: Nov 2010 Posts: 1,159 | I like the parts washer type set-up idea! | | | | | Joined: Mar 2004 Posts: 6,233 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,233 | Be careful with high pressure air on a closed cooling system, you will blow the radiator apart. I believe radiators are leak tested to about 15 pounds max. Mike B 
Last edited by Mike B; 06/01/2015 1:25 AM.
| | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Good point Mike, didn't have a radiator in mine.
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: Dec 2001 Posts: 14,522 Moderator: Welcome Centre, Southern Bolters, Legion Hall | | Moderator: Welcome Centre, Southern Bolters, Legion Hall Joined: Dec 2001 Posts: 14,522 | ...can't remember who/which, but one of the big diesel engine companies recommends dish washing detergent. Maybe pour a cup full of it in and let it. Not sure how it'd work on 60 year old crude but it may be worth a try. | | |
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