Cooling It
Nearly all '87-up Wrangler radiators develop a slight coolant leak where the upper plastic tank is clamped to the brass radiator core. Ours had begun seeping enough to kill any dog or cat that wandered by looking for a sweet drink of antifreeze. As a permanent cure, we went with a Novak Conversions high-performance aluminum replacement radiator (PN CR5087). The unit is pretty close to a bolt-in deal and its high-efficiency 1.5-inch core should cool our 4.0L easily no matter what. Novak also offers a dual 1-inch core version, as well as conversion radiators for Chevy and AMC engines.
To ensure we'll never have a radiator-hose issue for the rest of this Jeep's life, we upgraded to BRX's high-quality silicone radiator hoses. We ordered PN TJ27-KIT, which got us an upper and lower radiator hose. BRX even has silicone heater hoses. The silicone hose is resistant to all underhood chemicals, has a much longer life, and can handle four times the pressure of a stock hose. The hose also comes with a lifetime guarantee.
Tune in next month when we'll be turning our attention to the exterior for better looks, protection, and recovery capabilities.
Our upgraded cooling system consists of a Novak high-performance aluminum stock replacement radiator and a full complement of BRX silicone radiator and heater hose. We took our Wrangler to TAG Motorsports in Escondido, California, for the radiator install. | 
TAG's Jay Miller had our old radiator out in no time, while his trained helper monkey, Jub Jub, kept the Jeep's fender from floating away. |
There were some slight differences between the stock radiator and the Novak unit. Namely, the upper tank and radiator hose location on the Novack piece sits about 1-inch lower. Also, the drain plug is on the bottom on the Novak unit, which would require a hole to be drilled inmost aftermarketradiator skidplates if you'rerunning one. | 
Novak's directions reference the fact that the radiator comes with 5/16-inch cooler line bungs. Since our auto tranny cooler lines were 3/8-inch, Miller ordered some Edelmann 3/8- to 5/16-inch flared fitting adapters (PN 258650) from the local Car Quest. Novak recommends ordering its universal auto tranny line kit (PN RW-8045). |
Another snag Miller ran into was the shoulders on the tranny line adapters bottomed on the bungs before the flare could make contact with the seating surface. Miller blocked the passages and used a sanding disc to remove enough aluminum to allow the flare to fully seat. | 
Finally, Miller needed to remove some plastic from the fan shroud below the upper radiator inlet for hose clearance. We found we couldn't reuse the fan's self-tapping bolts to hold the shroud, so we used four 1/4-inch nuts and bolts instead. All in all, the radiator has excellent performance and incredibly sturdy construction. |