How Do I Replace a 1989 Nissan Sentra Radiator?

Your 1989 Nissan Sentra's radiator is the heart of the car's cooling system. It is important to have a working radiator to keep the engine at normal operating temperatures. Replacing the radiator on your Sentra can be done at home with normal tools. Be sure to take your time when handling the cooling system's hoses and components.

Instructions

Replacing the Radiator

1

Remove the negative cable from the battery.

2

Set the temperature control to full HOT inside the passenger compartment. Place a large drain pan under the radiator.

3

Remove the radiator cap. Loosen the petcock at the bottom of the radiator. Let the coolant drain into the pan.

4

Detach the heater hose from the connector pipe (using a flathead screwdriver to loosen the hose clamp) on the left side from behind the cylinder block. Drain the coolant into the pan. Remove the drain pan.

5

Remove the upper and lower radiator hoses and the reservoir hose, using your screwdriver to loosen the hose clamps.

6

Remove the cooling lines at the bottom of the radiator, using your screwdriver to loosen the clamps. Plug the lines with plastic plugs.

7

Unscrew and remove the water temperature switch at the bottom of the radiator.

8

Disconnect the fan motor wires from the assembly.

9

Remove the mounting nuts from the mounting studs using your socket wrench.

10

Lift and remove the radiator/cooling fan assembly from the engine compartment.

11

Separate the fan from the radiator by removing the bolts on the sides of the fan's shroud with your socket wrench.

12

Follow Steps 11 to 4 backwards when installing the new radiator. There are no torque specifications for any of the nuts and bolts; do not over-tighten them.

Filling the Cooling System

13

Ask another person to push on the three-way valve at the firewall with a 3 mm pin. The pin must go in the valve as far as possible.

14

Fill the radiator with new coolant mix up to about 3/4 inch from the bottom of the filler neck using a funnel. Cap the radiator. The pin can now be removed from the three-way valve.

15

Fill the reservoir with the new coolant mix to the MAX line with your funnel.

16

Turn on your Sentra and let it run at 2,000 RPM for a few minutes. Check for leaks. Shut the engine off. Add more coolant mix to the reservoir if the amount drops.

17

Loosen the drain plug in the upper part (on the right) of the cylinder head with your socket wrench. Keep adding coolant mix into the system until the plug leaks with the mix and the reservoir reads MAX. Tighten the plug when finished.

18

Reconnect the negative cable to your Sentra's battery.