The Stovebolt Site Forums The Shop Area General Truck Talk How to clean radiator

Hi All,

I am getting ready to install my radiator. Truck has not run for 3 years and it ran well before. I would like to clean out my radiator prior to install. Is there a good way to do this, anything I can pour in to let it clean things out? I had no problems with radiator before but since its out why not?

Leave it alone. Or, since it has been sitting, just stick a running water hose in the fill hole & let it run out the bottom for 5-10 minutes. There are loads of cleaning solutions out there, but their use could potentially clean away what was keeping the radiator running "well". New radiator (3 y.o.)? original? What truck?
If you did not cover/seal all openings on the radiator, assume some bugs or other critters might have moved in.
A local shop cleaned & pressure-tested my radiator for a reasonable price. That would be the best option.
Brad

I agree, leave it alone if you are not having a problem. I have heard more than one story of someone performing a maintenance flush of a radiator only to cause leaks. A radiator is one of those "if it ain't broke don't fix it" items.

The truck is a 50 1/2 ton. The radiator was rebuilt many years ago and always ran a constant 190 degree even on the hottest days. Ok, so I will flush it with water and install.

thanks!

Do a "reverse flush" where water is introduced into the bottom hose nipple and flows out the top. If you have an air hose handy, it's possible to rig a T fitting in the inlet hose and goose a quick shot of air into the flow to shock debris loose, but be aware that might also cause a leak to open up on a rotten radiator core.
Jerry

If possible only refill with water once installed, run it, then dump, do as many times as you like. Then Dump and catch in bucket ---probably 2 gallons is half or 1 3/4 gallon. Then fill with 2 gallon or less of straight antifreeze. May be a 16 quart system if an inline 6 or could be most likely 14 quarts --then adjust for 50% mix.

May clean out engine also and if you have a leak --no antifreeze wasted.

I always take mine into a shop and have them checked. It is not that expensive and insures they are in good shape. I had one just like you described and it looked good to me. The shop found and repaired some small leaks and did a pressure test and fixed the mounting brackets. These same guys have told me when not to do anything and told me when one was finished was well.

If you have not had the block cleaned out during a rebuild or major repair, that should be as big a priority as the radiator.
Also need the proper thermostat.

I think my cracked head problems on both my engines were caused by my cooling system issues. Both engines had been sitting for long periods.