The Stovebolt Site Forums The Shop Area Engine Shop cooling system cleaning

I read many posts from doing a search and I am still confused with the best way to clean the engine block from rust and crud, with-out removing the engine and having it cooked.
I bought some prestone cleaner and flush which I haven't used yet, but I read many people use cascade dihwaher soap, CLR and even one with muratic acid..don't think I want to try the acid route.
The radiator looks good but I know theres a lot of junk in the block...Just looking for an answer

I usually go with a garbage can and a sump pump to run my chosen solution through things. I let it run overnight or for the day, sometimes reversing the flow.
Then I blast compressed air in to force the solution under a little pressure and help dislodge any stragglers.

Tide laundry detergent works well also. It was also a vw tech bulletin for a way to flush an engine that had coolant in the oil. It was common for the oil cooler seal to crap out and let the coolant into the oil and oil into the coolant passages.

Caso, please explain these procedure in more detail. I have pulled the thermostat to get full flow and not clog-up the thermostat, but I am interested in how you flush this and what you use

DuPont used to sell a 2-part powdered cooling system flush product that came in a double-ended cardboard canister. The active ingredient of the flushing powder was Oxalic acid. With the thermostat removed, the powder was poured into the radiator and the system was topped off with water. The engine was run for at least 30 minutes with part of the radiator covered with cardboard to raise the temperature to the normal operating range. Then the system was drained, refilled with water, and the neutralizing powder (baking soda) was circulated for 10 minutes. The final procedure was a 10-minute flush with clean water followed by a refill with the proper antifreeze/water mix.

The same thing can be done by using "Rust-Mort" or one of the other Phosphoric Acid rust busters used for body metal prep, followed by a box of baking soda dissolved in water as a neutralizer. I used Muriatic Acid (technical-grade hydrochloric) for radiator flush when I worked at a concrete plant. The cooling systems of our concrete mixers got contaminated with limestone dust and Portland cement pretty regularly, and we had big drums of the acid sitting around for cleanup purposes. Worked great!
Jerry

I pull the thermostat and run a shop vac hose (or whatever I have that fits) from the Water pump outlet to the garbage can. So that's the 'Return' line.
Pull one of the heater hose lines and hook the other up in it's place to bypass the heater (and it's small passageways)

Then I pull the block petcock/drain and thread a fitting in to hook up the 'supply' hose from the sump pump.
Your local hardware usually has the brass fittings needed to adapt from one size hose ID to another.

In at the block drain Out at the water pump outlet.

If you have a way to block off the rad hose lines you could use the heater hose 'ports' I suppose.
I just went with what was easiest on the rig I was working on...

I usually start with hot water from my H2O heater to help with any grease or oil.
In the end I just wanted a way to circulate the water for hours without having to run the engine.

Terry - in addition to all the fine advice you will get here, you should run a heater hose over to an inline coolant filter. Your flaps should have them. When you knock the crud loose this will help to remove it - even if you only leave the filter in place temporarily. Otherwise you may do more harm than good. Would have saved me $3K in repairs to my diesel had I had one.

The best stuff we have found for removing rust - to the degree possible on an old truck is a f*rd product called VC-9. Not exactly cheap but it really does a good job.

Good luck

Most of those coolant filters aren't really filters. They slowly add an additive to the coolant to prevent block damage from cavitation in a diesel.

Some great ideas here, now I'll have to decide which to use..BTW, I don't have a heater in my truck. Thanks everyone for the imput

I hear ya Harold but I only have a diesel p/u, not a semi and the washable coolant filter I purchased is definitely a filter only. If I were better able to show photos I think you would be amazed at the amount of grit this thing traps. I rinse it off it at each oil change.

Again in my case this $100 setup would have saved me serious $$$ had I only known...

FWIW, when I rebuilt my 216, I had to spend hours digging and flushing the crud out of the block. This was AFTER the engine machine shop had "cleaned" the block (they simply don't do as good a job as they used to due to environmental regs on the chemicals that are allowed). Anyway, I could not imagine getting all the crud/scale out of the block simply by flushing as described above. Flushing might help a currently running engine, but mine had been sitting for well over 20 years. The crud was more like mud than rust scale and very tightly entrenched. In the end, I got if fairly clean. Good luck.

David is absolutely correct. My issue was a plugged oil cooler. It was plugged with grit that I have been told is casting sand and silicates from using the gold colored coolant.

The plugged area was a pipe leading into the oil cooler that had an id of 5/8". Plugged solid allowing no coolant to enter. I had to flush the coolant 9 times with no t-stat to get most of that junk out. But my coolant filter still traps all kinds of stuff.

BTW Simple Green worked the best for cleaning the oil out of my coolant system. Better than dish soap, dishwasher soap, and WAY better than Purple Power.

Good luck

Can anyone tell/show what kind of coolant filter they have. I've seen this discussed on other forums and they seem like a excellent idea. Thanks, Mike.

I bought mine from a place in California called IPR Research. Being machined aluminum with a magnetized, washable filter it is rather expensive but for the price of my repair it was worth it. Plus it is small and I needed the space savings.

Here is the link:
http://iprresearch.com/product.php?productid=105&cat=0&bestseller=Y

When the time comes for the 52' truck to have one I will use one of the spin-ons from Napa. Much cheaper

I have decided to go with the oxalic acid as Hot Rod Lincoln suggested I have the utmost admiration for his talent, experience, and advice. I ordered some online from amazon a little while ago and will report back with how it works...good/bad. There was a lot of rust/crud when I pulled the thermostat, so we'll see....Thanks again to all who replied