How to Replace the Radiator in Jeep Cars

by Contributing Writer

The radiator on a Jeep car is mounted to the core support just in front of the engine. The radiator uses thin copper-brass tubes to draw heat off the coolant and lower the operating temperature of the engine. Because these tubes are thin, they are prone to corrosion. If your radiator begins to leak, you must remove it from the vehicle and take it to a radiator specialist to be pressure tested. They will be able to tell you if the radiator can be repaired or must be replaced.

Under The Hood:

 How to Replace the Radiator in a 1998 Jeep

Open the hood of your Jeep and locate the radiator cap on the top of the radiator. Remove the cap and set it aside. Position a large, clean drain pan under the passenger’s side of the radiator, directly under the drain petcock on the base of the radiator.

Open the radiator drain petcock and allow the coolant to drain into the pan. Move up to the engine compartment and, with a flat screwdriver, loosen the hose clamp on the upper radiator hose where it attaches to the radiator. Push the hose off to one side so it is out of the way.

Move to the bottom of the radiator and remove with a wrench the two cooling lines for the transmission that thread into the bottom tank of the radiator. If your Jeep has a manual transmission, these lines will not be there.

Remove the lower radiator hose after loosening the hose clamp on the radiator end of the hose with a flat screwdriver. Push the hose aside. Locate the wiring harness connector that plugs into the electric fan on the radiator. Depress the locking tab on the connector and separate the two halves.

Locate and remove the two mounting bolts on the radiator with a socket and ratchet. There is one on each side of the radiator near the top. Set the bolts aside to use when you install the new radiator.

Grasp the radiator with one hand on each side and pull it straight up and out of the engine compartment. Locate the four mounting bolts that hold the electric fan and shroud on the radiator. Remove the bolts with a socket and ratchet, then remove the fan and shroud from the radiator.

Install the fan and shroud on the new radiator. Then, position the new radiator in the engine compartment, sliding it in from the top while aligning the dowel pins on the bottom of the radiator with the holds in the frame cross member below the radiator.

Install the mounting bolts from the original radiator into the new radiator and tighten them with a socket and ratchet. Connect the lower radiator hose to the radiator and tighten the hose clamp with a flat screwdriver. If your Jeep has an automatic transmission, connect the cooling lines from the transmission in the threaded holes in the lower tank of the radiator and tighten them with a wrench.

Install the upper radiator hose onto the radiator and tighten the hose clamp with a flat screwdriver. Fill the radiator with coolant and start the engine, allowing it to run until it reaches normal operating temperature. Continue to add coolant as the level drops, then replace the radiator cap. Close the hood of your Jeep.

Items you will need

  • Drain pan

  • Flat screwdriver

  • Wrench set

  • Socket set

  • Ratchet

 How to Replace the Radiator in a Jeep Cherokee

Drain the coolant from the radiator. Unscrew the radiator cap, then place the drain pan underneath the front of the vehicle. One most models, a hex shaped drain plug is located on the lower driver's side section of the radiator. Some models will have a plastic plug that requires a screwdriver. Collect the coolant in the drain pan.

Remove the fan shroud, or electric fan assembly for some models. Disconnect the power wires from the fan at the adapter, then loosen the two screws at the top of the housing and the entire unit will slide up.

Disconnect the upper and lower rubber hoses from the radiator. This may require a flat-head screwdriver for hose clamps, or a pair of channel-lock pliers for pinch style clamps. More coolant will likely come out of these hoses, so have a drain pan handy.

Remove the transmission lines connected to the radiator, if so equipped. Some models will use the cooling system to lower the temperature of the transmission oil. They connect to the radiator with a hex shaped line bolt on the upper line, and a quick clamp on the lower line. Some fluid may leak out.

Remove the condenser bracket bolts, on the top of the radiator.

Pull the radiator out of position, and slide it straight up to remove it. The condenser should stay in place.

Install the new radiator. Slide it back into the frame catches at the bottom of radiator channel, located in the back of the condenser.

Replace the top condenser bracket bolts.

Reconnect the rubber hoses, or replace them.

Replace the fan shroud or electric fan assembly. It slides down into the channel at the bottom. Fasten the two screws that hold it into place, and plug the fan into the adapter.

Reconnect the transmission lines, if so equipped.

Tighten the drain plug.

Fill the radiator with coolant. Crank the Jeep, and continue to pour coolant until the radiator will not take in anymore. Replace the cap with the engine running, and then fill the reservoir to the proper fill level. The channels of the cooling system may take additional fluid over the next few hours of drive time, so check the reservoir often.

Check and replace the lost transmission fluid at the dipstick, if so equipped.

Items you will need

  • Socket drivers and bits

  • Screwdrivers

  • Drain pan

  • Channel lock pliers

  • Replacement radiator

  • Coolant

 How to Replace a Radiator in a 1999 Jeep Grand Cherokee

Remove all the screws in the front grill, using the Phillips screwdriver. Place the drain hose on the petcock and into the drain pan. Use the pliers to open the petcock and allow the antifreeze to drain into the pan. Open the radiator cap to hasten the draining process. Remove the upper and lower radiator hoses, using pliers to squeeze the clamps to remove them.

Disconnect the electrical connector at the auxiliary cooling fan. Remove the four nuts securing the clutch fan to the water pump pulley, using a wrench. Remove the four bolts securing the engine cooling shroud to the radiator shroud, using the appropriate socket.

Lift the engine fan shroud and the engine fan out of the vehicle. Remove the four bolts securing the electric fan and shroud to the radiator, using the appropriate socket. Lift the electric fan out of the engine compartment.

Remove the four bolts that secure the radiator cross member to each fender, using the appropriate size socket. Lift the cross member off the radiator.

Detach both transmission cooler lines, using the special quick disconnect tool. Rock the radiator slightly rearward toward the engine and remove the air conditioning condenser-to-radiator bracket by removing all four bolts, using the appropriate size socket. Lift the radiator out of the engine compartment. Replace the radiator in the reverse of removal and fill with antifreeze and water.

Items you will need

  • Phillips screwdriver

  • Pliers

  • Drain pan

  • 1/4-inch drain hose

  • Set of wrenches

  • 1/4-inch drive sockets

  • Quick disconnect transmission line tool

  • 2 gallons antifreeze

 How to Replace the Radiator on a 1997 Jeep Grand Cherokee

Allow the engine to cool for three to five hours prior to working on the cooling system. Open the drain cap on the top of the radiator with your hand. Set a drain pan underneath the radiator, then open the petcock on the bottom to allow the coolant to drain.

Unbolt the grille reinforcement panel at the top of the radiator using the ratchet and set the panel to the side. Unscrew the hose clamps on the upper and lower radiator hoses at the radiator and pull the lines off of the radiator. Unscrew the transmission cooler lines on the radiator using the line wrench set.

Unplug the electrical connections to the fan using your hands. Unbolt the radiator support bolts using the ratchet, then pull the support away from the engine. Remove the radiator attaching bolts as well, then lift the radiator up and away from the vehicle.

Install the replacement radiator into the core support using your hands. Then reinstall the radiator attaching bolts, radiator support bolts and grille reinforcement panel using the ratchet.

Reinstall the upper and lower radiator hoses using the flathead screwdriver. Plug in any electrical connections using your hands. Then open the cap on the radiator and fill it with the prediluted coolant. Turn on the engine and let it run for 10 minutes with the heater set on the high position. After 10 minutes, turn off the car and allow it to cool down for an hour. Open the radiator cap when it's cool to the touch and add coolant as necessary.

Items you will need

  • Drain pan

  • Flathead screwdriver

  • 3/8-inch ratchet and socket set

  • Line wrench set

  • Replacement radiator

  • 50-50 prediluted coolant

 How to Replace a Radiator in a Jeep Grand Cherokee

Disconnect the negative battery cable before you begin the process of replacing the radiator. Then, remove the plug on the underside of the radiator and let the engine coolant drain into a resealable container.

Remove the upper radiator hose and lower radiator hose. Inspect the hoses, and if they need to be replace, this is the perfect time to do it. Unfasten all of the bolts with a wrench, securing the grill reinforcement panel, and take off the panel.

Unhook the transmission cooler lines, along with any electrical connections. Take off the radiator mounting support bolts, and remove the radiator support. Remove the bolts holding the radiator in place, and lift out the radiator.

Slide the new radiator into place, and tighten the bolts according to specifications. Reattach the radiator support and the radiator mounting support bolts.

Reconnect the electrical connections and the transmission cooler lines, and replace the grille reinforcement panel. Reconnect the negative battery cable.

Fill the radiator with a mixture of half engine coolant and half distilled water, pouring slowly to avoid excess air.

Start the engine and let it run for several minutes with the cap on very loosely to bleed air from the system, then top off the engine coolant mixture, if necessary. Replace the radiator cap securely.

Items you will need

  • Resealable container

  • Wrench

  • Replacement hoses, if necessary

  • Replacement radiator

  • Engine coolant

  • Distilled water

 How to Replace a Radiator in a Jeep Wrangler

Draining the Cooling System

Locate the petcock valve on the lower right corner of the radiator and place a waste oil collection pan underneath it.

Open the petcock valve by turning it counterclockwise, using needle nose pliers.

Wait until all the coolant has drained out then close the petcock valve by turning it clockwise.

Removing the Radiator

Loosen the hose clamp that connects the upper radiator hose to the radiator using a Phillips head screwdriver. Then pull the upper radiator hose off the radiator.

Loosen the hose clamp that connects the lower radiator hose to the radiator using a Phillips head screwdriver. Then pull the hose off the radiator.

Unscrew the transmission cooler lines from the radiator (automatic transmission only) using a wrench.

Unscrew the bolts that secure the radiator to the core support, using a socket.

Lift the radiator straight up to remove it from the vehicle.

Installing the Radiator

Lower the radiator into position behind the core support. Be careful: the cooling fins are thin and can be easily damaged.

Screw the bolts that secure the radiator into the core support. Tighten with a socket.

Thread the transmission cooler line fittings into the radiator. Tighten with a wrench.

Slide the lower radiator hose onto the fitting on the bottom of the radiator. Slide the hose clamp over the fitting and tighten with a Phillips head screwdriver.

Slide the upper radiator hose onto the fitting on the top of the radiator. Slide the hose clamp over the fitting and tighten with a Phillips head screwdriver.

Fill the engine with a 50/50 mix of antifreeze and water.

Run the engine and visually inspect for leaks.

Items you will need

  • Waste oil collection pan

  • Needle nose pliers

  • Phillips head screwdriver

  • Wrench set

  • Socket set

  • Antifreeze

  • Water