JKOwners Forum banner

Leaking Radiator Saga....

23522 Views 66 Replies 24 Participants Last post by  WNbirdman
Hi guys,

Have a CSF all aluminum 2 row radiation to keep my L83 Chevy cool. That it does extremely well! However, I am dealing with a constant leak, and this is my second replacement. Seems they fail within 6 -8 months.
I know Mishimoto has the same exact failure at about the same rate, and I will tell you mine failed with the 3.8 as well, as I replaced the leaking stock with the upgrade, anticipating the engine swap. It leaked before the V8 ever made it in......
Specifically where the fins meet the tank sides.
I am thinking about adding some Bars Leak stop product, but bypassing the heater core, to keep it from getting clogged.

What is you alls take?

I’m about to order a mid range plastic tank stock radiator so see if it can cool as well as the 2 row. Im super suspicious of the bar product......
61 - 67 of 67 Posts
Do you have it mounted with the floating spring hack or hard mounted?
I did not add the spring mod to the upper mounts as I didn’t plan on any major off-roading any time soon. Waiting on RMA for return but I will now add that mod when I get it back.
I did not add the spring mod to the upper mounts as I didn’t plan on any major off-roading any time soon. Waiting on RMA for return but I will now add that mod when I get it back.
Here's a parts list if it'll help (about halfway down the post). A little pricey but they're working well so far:


Sent from my LG-H918 using Tapatalk
Just an update to the saga, CRracing replaced my first radiator and it only lasted a little over a year and is now leaking at the core. The first one lasted 4 months and the second 14 months. After Motech’s first CFS radiator failure and 2 CRracing failures I think I’ll give the plastic OEM a try.
Did you also try the spring mod?

With the trouble you've had it almost sounds like an electrical ground problem. When I initially set up my system, I back-flushed the heater core and then flushed the system thoroughly with distilled water. Fill, run up to normal temp, drain, repeated three times. I also used the Royal Purple "Royal Flush" treatment, followed the instructions on the bottle. Flushed again with distilled water twice, then filled with Amsoil Heavy Duty Coolant. I was dealing with a newly rebuilt engine and didn't want to take any chances with gunk hiding in the block...

Another possibility - could you be running with a bubble in the radiator? A bubble may be hard on the radiator internals, maybe leading to faster corrosion. Some of the aftermarket coolant expansion tanks don't have much volume so if you're not checking the level at every stop for gas, it might be running too low. I've been adding maybe 10-12 oz every 1,000 miles or so, and that's from normal evaporation / no leaks.

I also added a diode ground wire from the radiator to the body. The diode only allows stray current to flow in a direction that will not harm the radiator, so the theory goes. Here's where I ordered the wire:

It would probably be a good idea to do a ground test of all your electrical components. Basically watch your coolant-to-ground voltage while the engine is running, and test each circuit by turning them on one at a time (lights, cabin fan, ac, dome lights, radio, left turn, right turn, brakes, etc). I've been meaning to do it on my jeep but haven't yet. There are more detailed discussions on the web for how to do it.

All that and 20,000+ miles with no problems so far. Not sure if any of this will help you but figured it wouldn't hurt. Good luck!
See less See more
I did not do the spring mod. I felt the crracing radiators dual rubber grommet isolated upper mounts along with the OEM rubber bushing to core support mount would more than isolate any adverse frame twist from average street use. I've found over the last several years that your advice is sound as I've done the fluid voltage check finding negligible voltage (less than 1 volt), always maintained fluid in the overflow tank, installed #6 wire radiator to frame ground, and used the original GM Dexcool antifreeze per Robbie's (Motech) recommedation. This issue is common as dirt on these LS Jeep mods and some of the kit developers have made good progress on resolving the issue with more reliable manufactured radiators. All I know is the crracing radiator, while looking like a very well made unit, has failed in the same way twice at the core tube to side tank junctions. Since the radiator is out of warranty I'm actually considering trying a repair using some HTS-2000 brazing rods I purchased several years ago. Has anyone heard of a recommendation on using the GM cooling system seal tabs?


See less See more
This is the first failure I have seen regarding this radiator. Mine was flawless for the 3 years I owned it. I used the same mounts as you and I used the GM pills that GM uses with all their aluminum head over cast iron block engines. I looked at the new Hemi Jeep at vendor day in Moab and rode in it . It's got a thinner radiator than I expected with plastic tanks. The multi speed fan was nice and quiet but it ran warmer than mine did, More in the 220 - 230* range. Mine ran 204 - 215* rage. I think you did a good job and good luck with the repair.
Thanks Scuba, it's good to hear you had good luck with the GM tablets. I'll give them a try.
61 - 67 of 67 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.