Pulling out the radiator to do a flush, yes or no?

My transmission cooling lines are leaking, so I got new ones and plan to replace them today.

Now the little angel on my shoulder says just do that and be done with it in less than an hour and with a limited mess.

The devil on the other shoulder says why not do a radiator flush too, while the transmission cooling lines are disconnected? And what easier way to do a really complete radiator flush, than to actually remove the radiator. Plus I think the trans lines are easier to deal with, if the big cooling hoses are removed.

The reason I have the itch to flush the radiator, there is brown sludge, maybe rust or mud, I'm not sure. I have one of those Prestone inline radiator flush systems, where you hook a garden hose to your heater line, but after more than 40 gals, the radiator is still full of muck. But no cooling issues, even with the aux fan disconnected, it never gets above 210. So one might say it aint broke.

Anyone want to chime in on this. I have all day, but only today. It needs to be running tomorrow, so I don't need to create any new probs, which I imagine pulling the radiator will do.

:spin1:

If it has to be up and running tomorrow then just do a normal flush and hook the lines up and go. If you had a couple of days for it to be down then I'd say pull it and take it to a radiator shop and have them to a full cleaning and pressure test which would ensure that there's no further blockages or small holes.

So it sounds like you think I really couldn't get the radiator that clean anyway, without taking it to a shop to give it a complete cleaning and testing. That makes sense. I was just going to let the garden hose run throught it for a while, but I guess that wouldn't do much.

By the way the jeep is a '99, so not that old, can't be that nasty. It's well maintained and sees only moderate wheeling every month or two.

once a radiator starts to rust, you're really not gonna get rid of it all by just doing a flush.

I was never a fan of that prestone/garden hose flush b/c you end up with a little bit of NON-distilled water in your system. Maybe i'm a perfectionist, but I'd rather do the flush in a bottle method, drain, fill with distilled water, run it for a while...drain, repeat....drain repeat...then fill with 50/50 antifreeze/distilled water.

if you have a lot of sludge that you want to flush with tap water then yeah you should remove the radiator and then replace it with another

Well I wasn't planning on replacing the radiator.

I have already flushed it with tap water the last two falls before the below freezing winter weather. Should I take it from you guys that that was a bad idea? It was not distilled water, just Chicago tap water. Then drained and filled with 50/50 distilled water and Prestone.

Tap water usually has lots of chlorine in it - or at least enough to corrode any metal (even some grades of stainless steel). Some radiators have an anode (anodic "plug", usually zinc I think) plug. Reason being, the presence of that plug, the corrosives will "attack" it first. Its a little more complicated than that, but thats the idea....

Anyway, as was stated earlier, once the inside of your radiator starts to corrode, you cant really do anything simple to stop it. Even though you flushed and drained it, its very difficult to get ALL of the tap water out of your cooling system.

lame

okay dude...its your radiator...

jmsull said:

Well I wasn't planning on replacing the radiator.

I have already flushed it with tap water the last two falls before the below freezing winter weather. Should I take it from you guys that that was a bad idea? It was not distilled water, just Chicago tap water. Then drained and filled with 50/50 distilled water and Prestone.

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If it's full of brownish chum, I'd pull it out and flush it as best I could-- I'd have a new one on hand just in case as they erode from the inside out. If it comes out safely and cleans up nicely, reinstall it and return the new one-- if not, you've got the new one to install. It's nicer weather to do this now than in the middle of July when you start another thread "I should have flushed my radiator in April, but......"

best of luck-- Shorty

If it aint broke don't fix it. :lecture:

I have a friend who is always messing with stuff that was working, after he breaks it from messing with it he has to fix it which always ends up being a never ending fix it project for him.

I have not flushed a radiator in over 25 years now here in Houston. I have run them with tons of sealer (dry brown Fiber pellets or Preston black colored sealer with the pellets in the bottle) junk in them for years.

All I ever do is change the coolant about every 4 to 5 years when I replace all the hoses, but I never flush anymore. When a radiator won't stop leaking with sealer I replace it, which is very, very, very rare. I have only had one clogged radiator that caused overheat problems in 35 years, and it was already toast when I bought the jeep!!!

I think a lot of corrosion problems (Frame and coolant areas) are caused by over flushing and over cleaning and by letting the vehicles set for long periods with out running the motors.

I personally have found the thinnest, crummiest radiators on vehicles that have poor electrical systems. Electrolysis will deteriorate the metal much quicker than flushing (per directions) will. Clean your grounds and get the crud out of it and it'll last for many moons.

I tend to agree with the "if it ain't broke....." theory, but if it's full of "mud" it's closer to broke than I would like.

Ok, I didn't mess with anything but the lines and that was more than enough a pain in the a$$. The connections were a pain, but I got it done. I took a look at the coolant and it looked pretty good. The mud, muck whatever was gone and it just looked like coolant so I left it alone. Must have done a better job than I thought flushing it last fall. Thanks all.

Ecomike said:

If it aint broke don't fix it.

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^And if it is then time for an upgrade.

Silly question - Is it possible to get a full flush using a garden hose(or other cold water source) with the thermostat installed? If it doesn't open, how does the water circulate fully? Also, is my understanding that the heater be on correct?

Here are a couple of articles on electrolysis in cooling systems, mostly with aluminum components, why it happens, how to cope and a simple volt meter test.

http://www.sancarlosradiator.com/electrolysis.htm


http://www.imcool.com/articles/antifreeze-coolant/whygoodradsgobad.php

Hmm, actually the second link talks about an aluminum/plastic radiator that failed due to corrosion and not electolysis. The corrosion suspect in the 2nd article is chlorides, sulfates and general hardness. To the point of the earlier post about using distilled water. ??

Many years ago, I decided to pre-empt a cooling problem, and flushed my system with a store bought flushing product. Followed directions, etc. Felt proud that I'd taken "action" to forestall a "potential" problem.
That potential turned "real" in short order with a leaking heater core!
If you already have a cooling problem, then it needs to be resolved; however, I'd be disinclined to use corrosive cleaners to flush the heater core, for reasons described above. I'd use pressure tap water, back flush the heater core, and let it go at that.
It would probably be beneficial to flush the block with a commercial flush solution, since water alone probably won't remove built up scale inside the water jacket. I would then remove the drain plugs from the block, and flush with pressure tap water. I've found that over the years, rust and scale will accumulate in the water jacket, down low, were normal flushing will not get.
And, yes, the thermostat needs to be removed to facilitate flushing.
As far as the radiator goes, I would not use corrosive cleaners, for the same reason I don't with the heater core--the material the tubes are made out of is very thin. The erosion caused by corrosive cleaners could easily cause a marginal radiator to start leaking. If you suspect a clogged radiator--due to engine overheating--I'd just flush with pressure tap water, with the hope that the clog will be displaced. You could follow with a flush with distilled water, if you're concerned about the affects of hard water.
My experience is, if a clogged radiator is causing overheating, the only real solution is to replace it.

You need to be real careful with city water supply pressure flushes. City water pressure can go as high as 70 psi. The heater core and radiator are designed for only 16 psi. If they are clogged enough and the pressure builds in the garden hose to over 16 psi you can litterally blow the tanks off the radiator and heater core. Espeically dangerous with heater cores as they are much smaller than radiators. Radiator has to be pretty plugged up to the point of only passing 5 to 10 gpm for the pressure to build up in a radiator flush, but if it is really clogged it can happen.

smcdonaldaz said:

Silly question - Is it possible to get a full flush using a garden hose(or other cold water source) with the thermostat installed? If it doesn't open, how does the water circulate fully? Also, is my understanding that the heater be on correct?

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Bingo, the tstat slams shut, I use the flushing method but I wait till the tstat opens again, then turn the water on. But I usually drain the rad first at the start by either dropping the lower hose or sticking one of those kerosene hand squeeze pumps in the neck, they are flexible enough to get down there. Eventually after 6 or 7 cycles you get most of the crud out.
I actually had thought about hooking up the hose to my hot water heater, I do that anyway twice a year to drain out sediment from it.
Now though I just hook up the sun machine to it but since I started using distilled water years ago I have never had any more brown sludge problems.

sjkimmel99 said:

Here are a couple of articles on electrolysis in cooling systems, mostly with aluminum components, why it happens, how to cope and a simple volt meter test.

http://www.sancarlosradiator.com/electrolysis.htm


http://www.imcool.com/articles/antifreeze-coolant/whygoodradsgobad.php

Hmm, actually the second link talks about an aluminum/plastic radiator that failed due to corrosion and not electolysis. The corrosion suspect in the 2nd article is chlorides, sulfates and general hardness. To the point of the earlier post about using distilled water. ??

Click to expand...

Exactly - thats why you should always use distilled water, not tap!