The jeepfan.com 2004 Wrangler TJ Unlimited has 195K miles on it and on a recent spring ride the plastic tank on the top of the radiator split. At first there was a bit of an antifreeze smell followed by spray on the windshield then all over the engine and fenders. Luckily we were close to home and made it.
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note the split right behind the label 
For some reason the cooling system in this Jeep has been our nemesis. We must have put $100 worth of antifreeze in this thing over a 2 year period. From thermostats, water pumps and freak mishaps is there no end?
Luckily replacing a radiator in a TJ isn’t a particularly big or expensive job. If you are doing it take the time to replace some other things if needed like hoses, thermostat, clamps and a cap. In addition, use the recommended antifreeze. Since we already have new stuff from previous projects we just needed a new radiator.
Removal
With everything cool drain the radiator into a container, dispose of old antifreeze properly – not down the drain. Detach the upper and lower coolant hoses and detach the transmission cooler hoses if equipped.
remove cap 
upper hose 
open drain valve 
drain 
lower hose 
transmission cooler hose
Next remove the overflow bottle, which just pops out of the holder and begin removing the fan shroud bolts. It’s not necessary to remove the fan shroud to remove the radiator. Just push it back toward the engine over the fan. Remove the radiator bolts followed by pulling the radiator.
remove the overflow bottle 
pull the radiator 
removal 
removed
Installation
Install the proper transmission oil filter fittings into the radiator. We put some thread sealant on them first to keep things from leaking. Gently place position the radiator down into the Jeep. The bottom 2 bolt holes on the radiator are slotted so the bolts can act as a guide/catch. Once it’s in place replace all the bolts. Reattach the fan shroud and all the hoses. Tighten everything up. Install the overflow bottle and double check all the hoses.
new vs old 
transmission cooler fitting 
installed – below view
Fill the system back up with a proper mixture of water to antifreeze, typical mix is 50/50. We always use distilled water too, this prevents minerals in most tap water from contaminating the system. Start the Jeep and watch for leaks, let the Jeep come up to running temperature and continue filling the system until it’s full. Replace the cap and test the system under pressure.
fill up
Check the levels several times after running. Air pockets will work their way out of the engine and may cause the level to lower. Here’s to another $195K miles.
Check out a previous article on this Jeep’s cooling system. Wrangler TJ Cooling System Maintenance
