CRL in a radiator

[mopar346]

Different question for ya:

I am on the road with my Comet about 1000 miles from home. The temp gauge runs higher than I like at 70 mph for a while in the heat of the day. The radiator isn't but about 10 years old, looks good internally and seems to flow well. The t-stat is a 180* and new as are the hoses and coolant. The coolant I drained out before I left looked very fresh but I changed it for GP. I want to do something just to see if it helps. I think I am gonna pull the radiator and back flush it with a garden hose with a pressure nozzle. I am considering pour CLR in it and letting it sit for a while and then flushing it out. My thoughts are since CLR clears calcuim and that is some of what builds up in a radiator then the CLR will help or at least ensure that there is no calcuim. The question is has any one done it? Do you know a reason I should? Any general thoughts on my thinking.

For the record, I have shot it with 2 heat guns and have a radiator cap with a temp gauge in it. The car/engine is not running hot, it is just reading higher on the gauge than I am comfortable with at extended highway speeds in the heat of the day. It does seem to run about 20* warmer than at 60 mph, which I guess is expected. Cap reads 210ish when my gauge is high, reasonable considering it is the top/return of the radiator. So why am I doing anything? Peace of mind and just to be certain the radiator is as clear as possible.

63.5 Comet S-22 260 V8/2 speed Fordamatic/3.25 8 inch/factory sweep gauge no numbers (always read 2/3 scale, reads 3/4-7/8 when I'm concerned).

I know it is a Chevy truck forum but there is a lot of knowledge on here.

Thank in advance, Kevin

[mopar346]

a little eye candy.

[wraprail]

I have never tried it or heard of anyone doing it but what the hell.
I say do it!
Whats the worst that can happen. I'm sure your gona get all kinds of posts after mine telling you all the reasons why you shouldn't do it all from folks who really haven't a clue.
Do it and report your findings please.
Posted via Mobile Device

[mopar346]

Thanks, that is kinda where I am at. What can it hurt?

Worse case, a radiator is available for $140, I am at a home base among friends so wont be stranded. I will report back either way, the results or if I don't do it.

[INSIDIOUS '86]

If anything I would say drain the coolant currently and then test it in a small glass jar with clr just to be sure there are no bad reactions to the antifreeze and clr.give it a day or two. If not go ahead!
Posted via Mobile Device

[78maliburat]

On several freightliners i have owned i used to pull thermostats out and drain ......... 1 can draino powder 1 bottle clr fresh water and let it run drain with clean water till it runs clear new thermostats and fresh anti freeze..have done it on my cars too

[andrewmp6]

Are you sure the temp gauge is reading true tho?A had a older mustang i thought was running hot by the gauge turned out the gauge was reading hotter then it really was.And are you running a fan shroud on it?

[INSIDIOUS '86]

If anything I would say drain the coolant currently and then test it in a small glass jar with clr just to be sure there are no bad reactions to the antifreeze and clr.give it a day or two. If not go ahead!
Posted via Mobile Device

[mopar346]

Thanks guys, Andrew I am sure it is NOT reading correctly, although I am also sure it is running hotter at 70 than at 60. But even knowing, I cant turn off the uncomfortable feeling of being a 1000 miles from home in a 50 year old car and having a temp gauge reading that far over. This my do nothing for it but it might might me feel better.

Insidious, good advance as always, I'll start the test tonight and report back.

[BigBlocksRule]

CLR isn't very strong, you should be fine. Or drain it and fill it back up with straight white vinegar which is a mild acid, too.
If you smell pickles when you're driving it, you'll know you have a leak!
Had the same trouble with my son's 383 we built with ProTopline iron heads. The thicker heads hold heat and cause the temp gauge to read higher. Once we verified what the water temp actually was, we quit being so concerned. 40K miles later, we're still fine.
Rode with a buddy in high school with an old Comet. Had bad motor mounts, every time he'd get on it, the tranny shifter went from about the 4 o'clock position to high noon. We'd roll down the windows and scream to make it sound like spinning tires, we had a ton of laughs in that old car.
You have a nice looking car, dude!

[homemade87]

If something happens you have to replace you may consider a alum radiator. I had high temps on longer hauls and hard pulls up hills and it cured mine. The alum seems to do a better job of heat transfer. My temp stays pretty consistent now. It sure helped my old 67 car.

[mopar346]

Thanks guys, aluminum is a good idea but not really an option for this car, it would be out of place as the only aftermarket piece (other than the rims I guess, but I have the original 13s w/hub caps).

[mopar346]

OK, the first part of the test is underway. I took a small amount of coolant 50/50 mix in a water bottle and added about 3 times the CLR. So far no issue and it has been mixed for about an hour, I even shook it up for good measure. I will check it again in the mornign and tomorrow afternoon.

[wraprail]

Originally Posted by mopar346

OK, the first part of the test is underway. I took a small amount of coolant 50/50 mix in a water bottle and added about 3 times the CLR. So far no issue and it has been mixed for about an hour, I even shook it up for good measure. I will check it again in the mornign and tomorrow afternoon.

Just don't drink it!!!

[mopar346]

Yea it does look pretty tasty and I could probably stand to have my pipes cleaned out so........

I checked it this morning and no change, no reaction, no gelling, no separation, no toxic smell. As far so good.

[Kurt L]

that's a great looking car there now,i've always liked that year comet. but then again they made some sharp looking comets in the 60's. don't know bout the CLR tho.but thought i'd comment on your car.

[mopar346]

Thank you Kurt, where in Florida you live, I'm in Quincy.

[turp mcspray]

My 87 1 ton pickup, had a really dirty cooling system. Even after a drain/flush/refill, it would get nasty blackish brown looking. I drained it and filled up with straight vinegar. Was going to run it that way for a week or 2. Ended up being a month or 2. Drained/flushed/refilled. Antifreeze has remained nice and green ever since.

[homemade87]

I tried the clr on calcium build up and was not that effective for me. Then I tried the works toilet bowl cleaner and was I suppried. That stuff did the trick on calcium. That stuff just melted off .I did not do it on a radiator , but if you have no sucsess you might try testing it. Just a thought.


Turp, A lot of shops will use muratic acid to clean and flush cooling systems. Muratic acid will desolve rust. But I dont think it will desolve calcium.

[mopar346]

I have ask in a number of places and I have heard vinegar, draino, toilet bowl cleaner and wheel cleaning acid (like in a detail shop) among others.

Again, looking in it from the top it is not heavy but I figured it was worth a shot. I will report back the results and even try to get some pictures to post if possible.

[theastronaut]

Originally Posted by homemade87

I tried the clr on calcium build up and was not that effective for me. Then I tried the works toilet bowl cleaner and was I suppried. That stuff did the trick on calcium. That stuff just melted off .I did not do it on a radiator , but if you have no sucsess you might try testing it. Just a thought.


Turp, A lot of shops will use muratic acid to clean and flush cooling systems. Muratic acid will desolve rust. But I dont think it will desolve calcium.

Don't use The Works if there is ANY aluminum in they system. We used to make (ok we still do sometimes ) "bottle bombs" from 32 oz Gatorade bottles, The Works, and aluminum foil... look it up on youtube!

[mopar346]

My brew still looked good a few minutes ago, so tomorrow afternoon if there is no change, I'm gonna do it.

I will report the results.

[mopar346]

Well, I did it this afternoon with no ill effects that I can tell but I really didn't see that it did anything. I remove the radiator, flushed it from the bottom with a garden hose and then laid it flat and filled it with the CLR. After about 30 minutes I poured it out and it was discolored so it did do some cleaning. I then rinsed it with water thoroughly and reinstalled it and filled it up. When I was rinsing it, it was real obvious when running the water through it that it is flowing plenty sufficeint and I would say normal, never backed up in the bottom tank and when you looked at the flews (spelling?) it was like a good shower head and all that could be seen were flowing well. After the t-stat opened I topped it off and then drove it about 50 miles back to the hotel, I ran 70+ for about 15 miles and it claimed to the same area that concerns me. Anyway it has probably cooler down by now So I am gonna go out and make sure it is still full.