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.

[codyC10kid]

How clean are you wanting it to get?I know they sell a adapter that Cleans the cooling system,Directions 1 drain antifreeze 2 install that heater core T Peace 3 hook garden hose up 4 remove your petcock from the rad (leave every thing hooked up 5 turn motor on and water on,run for about 5 min. or so till the water going on the ground is clean...i don't think id replace freeze plugs unless there leaking

[usar17]

Ya i've been doing that a few times a week, run it till its clear. but then after a few days the resevoir is dirty again and the drain water is brown. Old radiator has improved tho some. But I'm just concerned that the replacement parts will gunk up over time bc there is still crap in the motor. or i may just be paranoid

[bd]

If you've got a lot of sediment in the block, it could take awhile.  Hot tanking a stripped block followed by steam cleaning is an effective method.  Barring that - before you replace any parts or hoses - remove the T-stat then add some powdered Cascade to the radiator and drive the dickins out of it; drain it; flush it again with clean water until clear and see how that goes.  When you're satified, replace all the rubber hoses and the other parts you mentioned along with a new T-stat and 50/50 mix.  You might also consider adding a water-wetter like Red Line (http://www.summitracing.com/parts/RED-80204/), but the jury hasn't returned a verdict, yet.

A word of caution - if the cooling system is as laden with muck as you suggest, some of that rust was once part of the steel freeze plugs - you could end up with a leaker.  Personally, with that kind of neglect, I would also wonder about the condition of the head gaskets.  Take a good look at the T-stat and water pump gaskets when you pull them off and that may give you some insight.

[usar17]

well that's just it, engine doesn't look like it was neglected much. Doesn't leak a drop of anything on the driveway. Runs great. No abnormal sounds. The T-stat and pump gaskets look relatively new. Just seem to always get dark brown again after just a day driving. It may just be continuous crap from the radiator coming off that's discoloring it.

I have no experience with freeze plugs btw.

[bd]

Brown turbid gunk is sediment washing out of the block.  It can take awhile, but repeated flushing the way you're doing will gradually remove much of it.  Persistence is the key.

[Big Katz]

I had the same problem with an old Model T We restored. It sounds hokie, but we drained the entire cooling system and block and them mixed up some Tang (the kind you used to drink as a kid). We filled the cooling system with it and let it idle in the yard for 1 1/2 hours and then flushed it good. We pulled the covers on the engine and the cooling jacket was every bit as clean as hot tanking would have gotten it. I'm going to be doing the same thing to my Blazer next week as it has the same problem you do. My Grandma gave me the idea, she does it to her dishwasher to get rid of the rust stains from her bad water. My kids will also never drink Tang after seeing that! 

[bd]

LOL
That's why the FDA eliminated full disclosure of chemical additives to food - they don't want people to know they're slowly being poisoned with petroleum distillates and caustics!   

Now that you've posted this, we're going to start seeing Tang repackaged and marketed for auto maintenance!   

[Skunksmash]

Back in the day my dad's friend was a car dealer. He said they used cascade dish soap. Said they let it cycle a few times through the thermostat and it would eat all that crud outa there. I'd never try that myself. Now they have some really good professional stuff that radiator shops use, comes in two separate bottles i think.