Sometimes it’s nice to blow off steam, but it’s never nice when your Jeep does. With so many Jeep JKs on and off the road, it was only a matter of time before the performance-cooling market starting making upgraded radiators and cooling components. We were among the first to get our hands on a Flex-a-lite bolt-in aluminum radiator and electric fan system for the JK, and we couldn’t wait to get it into a JK.
The radiator is considerably larger than the factory radiator and features an all-aluminum construction compared to the plastic and aluminum factory unit. This makes it a robust radiator that won’t fail after miles of off-road abuse. It also comes with a Flex-a-lite electric fan and a Variable Speed Controller that allows the fan to automatically turn on and off with the temperature measured in the radiator, separate from the factory ECM.
We had the crew at Northridge 4x4 perform the install on a ’14 Wrangler to show the highlights. This is an easy installation, taking about half a day, and provides a significant improvement in cooling.
Northridge 4x4 started the upgrade by disconnecting the battery and draining the radiator. Most of the work in upgrading the factory radiator with the Flex-a-lite performance aluminum radiator and electric fan system is gaining access to the radiator. You’ll need to remove the grille, the filler plate between the grille and bumper, and the top radiator cover. The overflow bottle lifts up to come off the shroud, and there’s a wiring harness to disconnect on top of the radiator for the factory electric fan.
The new radiator from Flex-a-lite comes with a fully-shrouded electric fan already mounted, making this install that much quicker and easier. There are two versions of the radiator available: One for factory V6 engines and another with the inlet and outlet on the passenger side of the radiator to accommodate JKs with Hemi engine swaps. The radiator and fan systems are designed to bolt in without any hole drilling in your Jeep.
You can see that the Flex-a-lite radiator is about twice as thick as the original, with much larger side tanks. This increases both the coolant capacity of the system and its ability to transfer heat. Flex-a-lite’s patented side tank design is made from extruded aluminum and is hand-welded to the core for a durable, strong radiator that won’t fatigue and break with years of off-roading. Its finned design transfers heat 104 percent more efficiently than a composite plastic and aluminum radiator.
The radiator and electric fan combo includes a Flex-a-lite Variable Speed Controller that will turn the electric fan on at 60 percent power when it first activates and then ramp up the speed to 100 percent as the coolant temperature in the radiator increases. It also turns the fan on at 100 percent whenever the A/C is used, and it has a provision for a manual on/off switch, which can be handy for water crossings or if you do any towing and want full manual control. Flex-a-lite just introduced a 3-position switch that can be used to go from automatic control to manual-on and manual-off positions.
The Northridge 4x4 crew slid the mounting brackets into the radiator side tank T-channels and moved the factory rubber mounts from the original radiator to the new Flex-a-lite radiator. The new radiator uses all of the factory mounting points, and the A/C condenser will mount to the new radiator once it is in place. Snug the radiator brackets for now. They can be adjusted up and down once the radiator is in place to get the radiator in the exact position you want, and then the brackets should be tightened.
The JK that Northridge 4x4 installed this radiator in has an automatic transmission. Flex-a-lite does not put a trans cooler in any of its radiators; the company says that both the engine and the transmission are cooled better when an auxiliary transmission cooler is used instead of incorporating it into the radiator. Flex-a-lite offers a bracket kit and Translife cooler for JK applications. It fits JKs with or without the Flex-a-lite radiator, so you can have better trans cooling even if you haven’t upgraded the radiator. The bracket uses two existing holes, but you will have to drill two more to mount the bracket.
