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I have a 1930 Sedan and I want to clean the coolant system. I an looking for input on what is the best way to clean the system (including any recommended cleaning product) and then what brand of product to use for a rust inhibitor. Any suggestions would be appreciated. Thank.s
Drain the system. Buy ten gallons of evapo rust at harbor freight. Don’t get cheap, place ten gallons in the system, and run at idle for a few hours. Then you can top off the system to just below full, and run it that way for the summer. Amazing stuff, works slowly but the heat will increase the pace. It removes oxygen, won’t hurt anything. I had a car pushing out the radiator, did as I said, and fixed it 100 percent. Runs cool and doesn’t push water anymore. You must take your time. Trust me two hundred bucks for this fix is cheap. And the process is easy. It’s a rare occurrence when a hard problem like this fixes rust and scale. Organic matter will not get removed with this process. Only rust and scale. Try it. Ed
Maybe I’m wrong, but I’ve wondered if cleaning a cooling system could cause more problems than it fixes. Maybe I’m just being overly cautious but if a cooling system works, I’d be one to just leave it alone rust, scale and all. Sometimes on a 90 year old cooling system, wouldn’t disturbing whatever has caked the insides for so long potentially open pinhole leaks or weeping?
If you are having cooling troubles and have looked into all of the usual causes like retarded timing, running too lean, debris in the radiator, dragging brakes. . .then the next step would be cleaning the insides.
And what about doing a reverse flush?
Great topic so thanks. I will try this on the ’31 while the radiator is out for repair. I was planning to use citric acid but after reading about EvapoRust and your good experience I want to try it.
I cleaned on the radiator after I removed it and got practically no rust particles out; poured a gallon of lacquer thinner through it three times and got no grease out. I will rig up a container and let the engine idle and the water pump circulate it through the block.
As for doing more harm than good, it’s possible with products which are inappropriate or too aggressive. I ran into this with the 1927 Series 80 when I had to remove the head to repair a head stud thread in the block: the cooling jacket side cover on the block had a tiny drop of coolant which appeared to be weeping. When I flicked my fingernail over it, it became a stream of coolant. When I removed the cover I discovered crud built up on the inside of the plate and corrosion under the crud which had perforated the plate. I got a welder to run a short bead over the damaged area on the inside of the plate and reinstalled, and Bob’s your uncle. But if there is something wrong, IMO we need to man up, know it, and deal with it. It’s going to come to you sooner or later anyway.
i have used EvapoRust for cleaning parts, but never in an engine. It is amazing stuff.
Eddie: from reading your post, you say to just leave the EvapoRust in the engine for the summer season? It doesn’t foam or boil out?
Scott: For any in-chassis cooling system cleaning, I’d highly recommend putting a Panty-hose ‘footy’ stocking in the upper radiator hose, to collect any debris leaving the engine. Even on a fresh rebuild, I find crud in the footy-stocking each season.
The only problem with using something like EvapoRust would be if the water jacket around the cylinders, behind the water manifold/jacket cover looks like the engine in the photo. This engine had over 2″ of rust flakes and rust-sludge on the floor of the cylinder block’s water jacket. This engine had been run, with a freshly recored radiator, and when I removed the radiator to reverse-flush it to remove the inevitable crud from the engine, I found that none of this mess had traveled through the head and into the radiator !!
Syd: If you are having problems with coolant being ‘pushed’ out the overflow of the radiator, I’d recommend a reverse-flush first. It only takes a handful or less of rust flakes to plug up enough radiator tubes to cause the radiator top tank to ‘fill up’ and push coolant out the overflow.
I had reverse-flushed my ’33 club sedan’s engine prior to the Rochester Mn meet. When on the tour the second day, I ran the car up to about 55=60 mph passing a slow delivery truck, and the engine started to get hot. and hotter, and eventually I had to almost idle back to the hotel that afternoon. The system was full of coolant, but the high-rpm when I passed the truck stirred up some debris, that clogged the radiator..
When I got home, I reverse-flushed the radiator again, and got about 2-3 tablespoons of rust flakes, all about the size of a grain of rice.. The engine ran cool and still is at this time..
Greg Long.
Greg, It works great, and doesn’t foam. Heat increases the reaction. Since the reaction only removes oxygen, it does not attack gaskets, paint, or anything else. In a “terrible†system like you showed, I would treat it twice, first without removing the cover, as it will make cleaning out the “flakes†much easier and cleaner. Basically a magnet will work perfectly to take out all the remaining flakes, and it removes all the powder like particles. The chemical is non toxic and can be flushed down the drain. It leaves behind the ferris metal, and if it’s loose in the system with all the oxside gone it is a neat and clean job. I ran it in an engine for nine months and probably one thousand miles. The inside of the block and head looked like they were sand blasted and then painted cast iron gray/silver. They system was perfectly clean. The car stopped pushing water out the over flow, but I still removed the radiator and back flushed it. This stuff will take a marginal system and make it drivable, but removing the jacket cover is still the best option. I recently purchased the 1927 Snap On socket set, and placed the tools in th evapo rust for a few days and brushed them with a nylon brush. The tools came out perfectly rust free without looking like they were sand blasted.
Syd,
My 1930 had a similar looking cooling system to Greg’s with lots of sludge and chunks. I agree with Greg’s suggestion that you remove the water jacket cover, but use a power washer on the junk out to the block. A power washer makes a mess, but it’s the only thing that will dislodge the solids from the other side of the cylinders where the exhaust valves live and the hottest part of the system.. When dry, use compressed air to remove anything the water missed. You’ll be shocked to see what debris comes out.. Greg also suggested the pantyhose filter in the top radiator hose. This is mandatory !! This cleaning really shakes things up. You will risk clogging that expensive radiator if you don’t.
The Evaporust idea sounds great. Thanks, Ed, I’ll try it, but might have a tough time getting ten gallons of it into an eight cylinder engine. Tom Barrett
Thanks to everyone for the excellent input, much appreciated. I would like to qualify my question. I have a car that runs cool and rarely gets over mid-way on the temp gauge. I do have some rust in the water and a little sludge but you can see the top of the inside of the radiator and it is clean metal. I was interested in what I might do to clean the water system and then add a good rust INHIBITOR so that I do not get a rust problem.
Ed, with this in mind would you suggest the Evaporust, run for awhile, drain, flush and the add what?
Many thanks to everyone who has offered their help.
Syd,
Oops. Sometimes we just grab the ball and run, even if it’s in the wrong direction. Still good info though.
Try Pencool 3000. It’s a cooling system additive used in the trucking industry, and compatible with all metals. Just add some to your coolant and it will protect the whole system. Can be found on the internet and is effective with pure water or antifreeze.
Is there only one Evaporust? Amazon has a 5 gallon pail for $80.00 Jim
EvapoRust also offer a product specifically for cleaning cooling systems: see their web site for details.
Evaporust is a chelating compound. So is feed grade molasses, which is a lot cheaper. I just got my first batch of rusty parts out of a 9 to 1 water to molasses bath and there was absolutely no rust. It works slow, but it works great and leaves nothing harmful. Just a thought.
The feed-grade molasses is as Bill Lyons wrote much less expensive, but slower. Another thing is that EvapoRust does not have much of an odor. But Molasses REALLY STINKS! So remember to open the containers outdoors or in an open work area. If you open the containers to remove and rinse off the rust and molasses indoors, you will think you have a broken sewage pipe in your house !!
Greg Long
Jim,
I saw it on Amazon with PRIME @ $22.95 per gallon, but a TWO-PACK is $99.00 (HUH?)!
Figure that one out!
Peter
Must be politicians pricing it so you won’t use much.
Syd,
When Greg first mentioned the molasses to me, he did mention the odor, so I have mine outside and covered with plastic. One should also be careful as it also attracts animals when it is outside.
Bill
Looking at the Evaporust site they have a “Thermocure” product specifically for cooling systems.
It appears Evaporust itself doesn’t need heat to work, just speeds it up?
I ask because I rigged up an aboveground pool pump and filter to flush the block without the radiator (run for days) before running the engine. Sounds like it might be worthwhile to repeat that step with either the evaporust or Thermocure to get the last of it.
I figured that no amount of cleaning and flushing was going to dislodge everything that will come loose with a hot engine vibrating at full power so I installed a Tefba radiator filter and rare earth magnet to catch the chunks big enough to plug the radiator – I think it is handier than the pantyhose to check and clean, but of course not hidden.
Jim
Evapo rust will remove the oxygen, and thus much of what is stuck to the walls and in the bottom of the block will reduce in size by 60 percent. It only leaves behind ferrous metal. Buy two five gallon pails if you need it. Do the math on making gaskets, breaking bolts, stripping the 40 holes in the block, Ext………even if you spend 150 bucks on the stuff it’s cheap! I never like shortcuts or “miracle†cures, but this stuff is worth the money. That’s why I said to use it before and after you remove the water jacket cover. It’s impossible to flush all the little particles out of a radiator even if you try twenty times. Do the math on three tanks of gas for your car…………don’t let the modest price of this stuff make you run a batch at 50/50. Run it straight. I am a very happy customer several times over.
Syd,
To add to Tom Barrett’s comment there is also a NAPA KOOL cooling system treatment that I have used for over 8-years.
It is quite similar to Pen Cool 3000.
I am happy with the product and I have not seen any rusty liquid or solids when I do my annual system drain.
Peter
Peter,
It was 1-5 gal. pail for $80 and 2-5 gal pails for just over $200. I guess volume doesn’t change their logic. Jim