Cleaning up the cooling system

[usar17]

Alright so my radiator looked like a swamp inside it. Decided to buy a new radiator, heater core, and all new hoses.

May buy a new water neck and pump also.

Question is...beside pulling the motor out and doing a complete break down to clean it, any tips on flushing out the interior water passages? I don't know how much i trust myself popping out the freeze plugs and scrapping it with a screwdriver like my buddy said. Just trying to get it all nice and clean. Been changing the water in the whole system once a week for a month now trying to clean it up. Ran radiator cleaner through it for a day on two separate occasions. Decided its time to swap the rad and see what more i can do.


FYI: I have not been having any overheating problems. Just preventive maintenance.

 

[crazy4offroad]

I'm not sure how safe this really is but it "sounds" like a good idea, hopefully some of the others can chime in on this...
CLR. I'm wondering if you added a bottle of CLR to the radiator if it would dissolve the mineral build-up you get in the passages, without harming the radiator, heater core, hoses, gaskets, etc. Worst thing I can think of happening is the heater core or radiator getting plugged from a piece of scale that might break loose instead of dissolving. Anyone else ever thought of this??

 

[usar17]

lol good in theory.

Well i have purchased all new hoses, radiator, and heater core. Just don't want the new stuff getting gunked up because i over looked something in the motor.

 

[guitarfreak235]

my radiator was in similar condition, basically had slop in it. i used a flush kit that pumps water in/out while the engine is idling using a garden hose. did this once a day for a week or so for about 15 minutes. i then used radiator cleaner for one final flush and it stays very clear now. since you already have the new parts, maybe try the flush kit and see if you could return the other stuff? it may be worse off than mine was but worth a try. also the flush valve is integrated into my radiator hose so it is easy to do a thorough flush anytime

 

[Irishman999]

Glad you posted about this, I just did mine a couple summers ago.

First step is remove your thermostat, re install the housing without a gasket.

If you have alot of calcium flakes get a garden hose with a nozzle that will fit inside your heater hoses. Remove the lower radiator hose at the radiator, Plug your garden hose into the heater hose that goes into the radiator and flush all the flakes and junk out.

Next get a bottle of radiator flush from the auto parts store with the most warning labels about health and safety, the nastier the **** is the better. Re install the lower hose and introduce the chemical cleaner into the cooling system and fill with water. Let the truck idle and get up to operating temperature with the solution inside, let it run for a while while warm. Let cool and drain the system again.

Mine came out brand new looking, as far as popping out freeze plugs, that sounds dumb as hell.

 

[chengny]

I'm not sure how safe this really is but it "sounds" like a good idea, hopefully some of the others can chime in on this...
CLR. I'm wondering if you added a bottle of CLR to the radiator if it would dissolve the mineral build-up you get in the passages, without harming the radiator, heater core, hoses, gaskets, etc. Worst thing I can think of happening is the heater core or radiator getting plugged from a piece of scale that might break loose instead of dissolving. Anyone else ever thought of this??

I have used CLR and Bar Keepers Friend (the BKF needs to be mixed with hot water to get it into solution) to clean radiators several times with no ill effects.

I started doing this because the radiators were original - OEM with brass tanks and copper tubes. They were beautiful - had no leaks and the fins were all there. Looked great form the outside.

But inside was another story, the tube ends (where soldered to the tanks) were so fouled that flow was being restricted. The watersides of the tanks were encrusted with deposits as well (so the assumption was that the inner walls of the tubes were in similar condition).

There are no more radiator shops around here, so I decided to "boil" them out myself. Nothing to lose; otherwise they would have been junked.

I have only done this with the radiator out of the truck and lying flat (outside and on a wooden picnic table). Radiator cap is on and the small connection to the expansion tank is capped

Pour a whole quart of CLR into the radiator and top off with city water. I use ZEP brand - it has a higher concentration of acid (hydrochloric & sulfamic) than the big name brand. If using Bar Keepers Friend (oxalic acid) mix half a can of powder into warm water and stir until you have a solution that can be poured.

Let it sit for hours. When you want to check the progress, dump the acid/water out (save it in a bucket - it still has plenty of life). Using a garden hose at full flow, flush the waterside out. Go in both directions. Lift and shake a couple of times. When no more deposits are getting flushed out, pour the acid back into the radiator. It helps if you filter the re-used solution through a piece of window screen or similar.

With several applications (dump and flush with clean water between) the deposits will be gone and the copper and brass will be a golden color.

When satisfied that you have clean surfaces and will get good heat transfer/coolant flow, do a final long flush to get any remaining acid out. If it makes you feel better, you can use baking soda to neutralize.

This is only for a last resort on old-style brass/copper radiators. I wouldn't waste the time on the new aluminum ones with plastic tanks.

 

[usar17]

My radiator is shot anyways so that's getting replaced tomorrow. Just looking for ways to clean up the passages in the motor. Unless they don't really gum up over time. I have used the flush kit. Ran the hose through it ever day. still always came out brown the next day after refill.

 

[Irishman999]

The CLR info is great, that sounds like it would be great on rusty water jackets that are causing the brown color in the water. Last time I saw a radiator shop was 2002 and it was a small mom and pop's shop that was closing down. I like the older style brass units just because they are repairable, they do still sell them but they are twice the price of an aluminum one.

Couple things I forgot to mention, those plastic T fittings you get with flush kits always burst, ask how I know haha. Before you go through the heater core replacement, dont use the cheapest one you find. I made that mistake and mine burst during a blizzard.

 

[1low4x4]

searching through old threads I came across this one and thought I would add a little bit. do not double up on those coolant passages cleaner products. And only run them for the time it says to. They will eat up your aluminum radiator if you are running one. Ask me how I know. Also, you can flush all you want, but if you do not remove the plug in the block, not the freeze plugs but the drain plugs on either side, you will never get out all the junk that's in there. Pull each plug and let the motor run with a hose stuck in the radiator and thermostat like Irish man said. Also, another thing that will never allow you to have clear coolant is the lack of a ground from your engine to frame. I went months trying to figure out why my coolant turned rusty brown, after I flushed it many many times and with cleaners and all new components. My radiator guy mentioned electrolysis, and sure enough I had a small ground from the head to firewall but none from the block to frame. By put a strap from the head to the frame and ever since my coolant has been bright green.this is just for anyone coming across this thread in the future