Cooling System Flush Advice Needed
 

Hey gang...

Could use some advice. I had a mildly used 350 crate motor that i put a cam and aluminum heads on. Sat for years but i cleaned it up best I could in process.

I setup on engine stand and used brand new nice radiator for my truck to break cam in. All is good but after running it, but now I noticed the radiator hoses have a crust on the inside of them i'm guessing from the messy internals of the engine cooling system. I could tell when i gave them a squeeze. It was like a crunchy film had attached inside the hose. Haven't inspected further.

What's the best way to flush some of this out while it's on the stand so that don't ruin or plug up my new radiator or get a thermostat sticking? I want the engine tuned and good before i install in painted truck. Are there any honestly good chemical treatments to get all the passages, hoses, radiator as clean at least as possible without disassembly and hot tanking the thing?

Thanks in advance

Re: Cooling System Flush Advice Needed
 

I use tide, in powder form then flush repeatedly.

Re: Cooling System Flush Advice Needed
 

Interesting....

How much tide, how long running, and how many flushes? Do you do that with the antifreeze in it or drain and refill with tide and water? Does it work better than some of the chemical flushes sold at the parts stores?

Re: Cooling System Flush Advice Needed
 

Jet a scoop or a serving from a laundromat. I drain the system first and then go through a heat cycle with the detergent in the motor/radiator. I flush until clean water is all that’s left. It’s time consuming but effective. Actually done this a few times when oil coolers has crapped the bed and put oil in the coolant system.

Re: Cooling System Flush Advice Needed
 

Did you use distilled water + coolant for the cam break in? A lot of tap water is 'hard' or full of calcium products.

If you are worried about damaging the new radiator, use an old one for the engine flush process.

Have you installed a new heater core? That can be another source of gunk getting into a new clean system.

Re: Cooling System Flush Advice Needed
 

I used pre-mixed 50/50 antifreeze. And its too late on the old radiator for break in as I/ve already done it on an engine stand. It has to be be out of the block as every other part was brand new when i added fluids and did break in.

Now i just have to get it as clean as I can while on the stand before i put the engine in the truck. I've seen some chemical flushes such as "Thermocure".

I know i may not get it perfect, but i want to get as much crap out as I can.

Re: Cooling System Flush Advice Needed
 

Ive never done it but i heard CLR does a good job

Re: Cooling System Flush Advice Needed
 

Interesting read here; http://www.sancarlosradiator.com/VoltageDrop/flush.htm

When I flush a cooling system I just use the system he calls "The Live Flush" which is rinsing out the old coolant, adding a good commercial coolant cleaning agent, running it for a few days (at least 100 miles), then drain, rinse and refill. Seems to work for me.

Re: Cooling System Flush Advice Needed
 

I used cascade just like hollow says he does with the tide ,came out nice and clean . Take your thermostat out while doing this

Re: Cooling System Flush Advice Needed
 

Drain the system, which means the radiator and the block. The block has plugs near the motor mounts. you might need to poke the crap out to make the coolant drain.
Flush with whatever you like.
Check and repeat as desired until things work/look as you desire.

Re: Cooling System Flush Advice Needed
 

Did you take the hose off and look inside? Hard to believe it could build up a crust that fast, are you sure it's not the spring inside the hose you feel.

Re: Cooling System Flush Advice Needed
 

That gunk is heavy and it seems to settle at the bottom of the water jacket. Popping the freeze plugs provides a great access point for flushing it out. I even turned my engine upside down on the stand and really gave it hell with one of those siver "Gilmore" branded garden hose pistols.

Re: Cooling System Flush Advice Needed
 

I seem to remember small blocks also have a drain plug in the block water jackets, lower sides of the blocks.

Re: Cooling System Flush Advice Needed
 

I don't understand how even if it had rust in the block how it could attach itself to the inside of the water hose especially with such a short run time.

Re: Cooling System Flush Advice Needed
 

Yes, I'm puzzled too guys. I'll have to pulpit apart and look.

When i squeeze the rubbers hoses you can hear it crunch like it's a film of rust coated along inside of hose.

Re: Cooling System Flush Advice Needed
 

I'll bet what you are feeling is the spring inside the hose.
Some have springs some don't.

Re: Cooling System Flush Advice Needed
 

I can tell you for a fact I had the same situation as dhunt00c. My upper rad. hose crunched and when I opened up the thermo housing a bunch of what looked like red kitty litter dumped out. I've owned this truck for thirty years and there was never a spring in the upper or lower rad. hoses. I took pics and posted them on FB, otherwise I'd post them here too. I have a separate post on the GMT400 group discussing this same situation. That's why this post is interesting to me as well. I'm currently driving my truck around locally with flush cleaner in the cooling system.

Re: Cooling System Flush Advice Needed
 

I never said it couldn't happen but that's a lot of rust. I'm just saying in my 40+ years of working on these old trucks and other cars I have never seen that much rust come out of one. Did you have any type of radiator stop leak in it?
I have seen a heater core get stopped up with rust but never a radiator hose.

Re: Cooling System Flush Advice Needed
 

Could you define mildly used crate engine. If that rust came from the engine I would be tearing that engine down before I put it in my nice 72 truck.
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Re: Cooling System Flush Advice Needed
 

I have two other vehicles that I use as DD's and this one is relegated to more of a work truck when I need to load stuff and go somewhere. This truck sits more these days and some PM got put off, obviously, and a big mistake on my part. I did have some stop leak in there, but I can't even remember what kind.
I probably could've done a better job of flushing this engine out when I installed it six years ago after storing it for a long time.

Re: Cooling System Flush Advice Needed
 

OK, when I say mildly used, it's probably very low mileage / hours of run, but it's an old engine and sat for a very long time.

In my situation, there is no heater core. It's just the engine, the water pump, the thermostat, and the new radiator.

Re: Cooling System Flush Advice Needed
 

Wow. :dohh:
I wonder what could be used to passivate a new engine. I'd be inclined to fill that rusty engine with Evaporust a few times. But then I still wonder if there is a way to passivate the jackets... :hmm:

Re: Cooling System Flush Advice Needed
 

First thing you should do is pull the radiator hoses of and see what's in there.