Any tired and true method or suggestions
 

I need to FLUSH out the cooling system. The radiator was cleaned and checked about 2-1/2 years ago BUT overt the last two years I noticed that my coolant was getting more "brown" than staying "green" SO I've drained my coolant and want to flush my system the best I can while still in the car and operable. SO any product and or processes one might recommend for the most effective FLUSH???

Re: Any tired and true method or suggestions
 

I had good results in the '51 Merc I put in my car, by first flushing with clear water, then using a commercial flushing product (I forget the brand), and finishing up with two successive applications of "Rust 911". each allowed to "work" for two days and followed by a plain water flush.

Here's a picture of the results through the water pump opening.

Re: Any tired and true method or suggestions
 

Rockfla,

I have a KR Wilson radiator flushing nozzle. It works by hooking up a hose and an air compressor to force water through the top of the radiator opening. You can use it with the system in tact to loosen up the gunk and then take off the lower hoses and let it run out the bottom while forcing the water through it. The gunk in the block will drain out from the lower hose as well. It will take a few times to get it all out, but it worked pretty well.

If you'd like to use it, send me a PM and I'll ship it to you on loan.

Here is a pict of what it looks like

https://www.worthpoint.com/worthoped...ator-537929055

Tim

Re: Any tired and true method or suggestions
 

Tim


Did you use it in conjunction with any cleaner/flush type product?? I would assume it would work best to fill the system with water and drive it to get it to operating temperature THEN drain, hook that up and proceed to flush??

Re: Any tired and true method or suggestions
 

I didn't, but I can't see why you couldn't. Depending on your compressor settings, the water comes out with a good deal of force.

I keep doing it until the water ran clear.

Re: Any tired and true method or suggestions
 

Don´t run cold water into your hot engine. Better use it on a cold engine or if you have, use a hot water source on a hot engine.

Re: Any tired and true method or suggestions
 

Kinda low-tech, but I filled my old Buick radiator with vinegar and drove her some for a few days. Did that along with the pantyhose filter at the radiator input and couldn't hardly believe how much crud I got out. Haven't tried that on a flathead V8 yet.

Re: Any tired and true method or suggestions
 

do the vinegar flush, leave the rest alone. cheap effective,

Re: Any tired and true method or suggestions
 

100 percent vinegar or diluted-?

Re: Any tired and true method or suggestions
 

X 3 on the vinegar flush. Was outstanding on my '41

Re: Any tired and true method or suggestions
 

It's already pretty dilute. Go to the dollar store and get enough to fill her up.

Re: Any tired and true method or suggestions
 

Back in the spring my36 radiator (Walker 3500 miles) had a top tank leak. Removed but concerned inside was rusty and full of sludge. Engine only had 7000 miles from full rebuilt by my dad in NZ. Only ever had prestone & distilled water.
Had radiator repaired and cleaned. Capped block and filled with vinegar. Left for 2 weeks drained and flushed. Now filled with Rust 911. Set a week drained and flushed. After all this looked like something growing in cooling system. Removed a great running 36LB engine stripped and had shake n bake cleaned. Then major pressure wash. Next soak in Rust 911 for 3 days. Another pressure wash. Here’s before and after. Ready for valve job and hone. Wash and reassemble. Here’s before stripping and after my extensive cleaning process.
The last is at very bottom of water jacket. It’s spotless.

Re: Any tired and true method or suggestions
 

How long should the vinegar be left in AND does that go for the Radiator too?? OR remove the hoses and block off the block?

Re: Any tired and true method or suggestions
 

Kiwi's experience / method is spot on. A comment about vinegar... the stuff I bought came from Costco, in gallon jugs. (inexpensive). It is labelled 5% acidity. It very dilute, as bought. (I have the feeling that I bought 95 % water.) My point here, don't dilute it more.
I ran a simple little test... I put a rusty wrench in it, and let it sit. No visible action in a few days. At the end of a week, could see minimal action. At the end of two weeks, could see fair results. So, my point being, run your own test. I would likely fill the entire cooling system, and wouldn't even check on it, for two weeks minimum. And, of course, then I would likely be concerned about what is being done to the water pump seal, hoses, and who knows what else.

Re: Any tired and true method or suggestions
 

I got to thinking (always a sketchy affair) about homebrew radiator cleaners, and thought to myself "Self, what about CLR?"

It is after all "calcium, lime, & rust remover". That should pretty well cover everything likely to be found in a cooling system, I'd think. Turns out, after a quick search of the intertubes, they must have thought of it too - they sell a "Pro" version of CLR specifically for radiator or cooling systems. I don't know how it differs from the amateur version, nor have I tried it personally.

Re: Any tired and true method or suggestions
 

BOBH


Im thinking I might pull the hoses and water pumps, make a couple of blank off plates and just doing the block by itself......MY radiator still looks nice and clean through the filler neck SO I was thinking I will have my Rad guy flush it again for me to make sure on it!!!!

CRANKSTER
That funny Ha Ha, as I was wondering about CLR from the grocery store myself BUT the small bottles would take a ton to fill the system up!!! Far be it from me to research their product further!!!!

Re: Any tired and true method or suggestions
 

Oxalic acid, which was used as radiator flush from GM, apparently discontinued. Available in hardware stores as wood bleach. Check the label, not all wood bleaches have it as an ingredient. From what I have read, 1/2 -3/4 cup per gallon. Either drive car for an hour or so or let in radiator for a few days. This is followed by a baking or washing soda rinse to neutralize acid.

Re: Any tired and true method or suggestions
 

The vinegar worked great for me too but it broke so much stuff loose that it plugged my radiator up after driving around. So from now on, I use adaptors I made to circulate water through the block without having the radiator in the process.

Re: Any tired and true method or suggestions
 

“I use adaptors I made to circulate water through the block without having the radiator in the process.”

This is what I did to accomplish the above. Just some 1 1/2 PVC, fittings and 1 3/4 I D radiator hose. I was going to put a trap on the down pipe by the water pump. Just a “T” with a short piece of pipe and a plug to clean it out and screen at the pump to prevent the reentry of debris. My thinking was the particles would drop into the trap on their way down the pipe.I ended up just using screen at the pump. I brought it up to temp, 190*-200* and let it cool. Cleaned off the screen and flushed everything. Cold weather shut my project down but I’ll resume in the spring. I have a gallon of RUST 911, I’m gonna give that a go when it gets warmer.......Mark

Re: Any tired and true method or suggestions
 

Robert do you know the history of the engine? Was it flushed of all the casting sand when rebuilt? I’d be trying to jack the rear of the car as high as possible and with the hoses off and water pumps removed, using a pressure washer to get the sand out of the bottom of the water jackets, let it run out the bottom hose outlets. If you get the heavies out the acid soak will be much quicker to neutralise the rust. Let us know how you go. Dan.