How to Backflush Cooling Systems

A backflush is a common way to clean out a car's cooling system. This process is often done to completely remove any coolant or anti-freeze that might still remain after the radiator is drained.

Instructions

1

Backflush cooling systems by purchasing a backflush kit at a local auto parts store. A backflush kit contains plastic T-tubes, a backflow prevention coupler and a plastic splash tube.

2

Allow your engine to cool completely before opening the radiator cap or disconnecting any hoses.

3

Cut the heater inlet hose with a utility knife. This is the hose that runs along the firewall from the radiator to the front of the engine. It is generally on the driver's side of the engine compartment.

4

Install the T-tube from the backflush kit that fits the heater inlet hose. Use the hose clamps that connect the inlet hose to the engine to tighten the T-tube securely.

5

Remove the radiator cap and install the splash tube from the backflush kit. It should snap right into place and form a seal.

6

Install the backflow prevention coupler from the backflush kit to the end of a garden hose. Hook up the other end of the hose to a faucet. Then connect the backflow prevention coupler to the T-tube you just installed on the end of the heater inlet hose.

7

Drain the radiator by opening the radiator plug at the bottom of the heater coils of the cooling systems. Use a plastic container to collect the fluid.

8

Reconnect the heater inlet hose to the engine using the remaining opening of the T-tube.

9

Start the engine of the car and turn the heater on high.

10

Turn on the faucet of the garden hose. Within a few seconds, you should start to see radiator fluid pour out of the plastic. You may want to use another plastic container to catch the fluid until clean water comes out.

11

Turn off the engine.

12

Turn off the water faucet and disconnect the garden hose from the coupler.

13

Remove the plastic splash tube from the top of the radiator.

14

Allow the water to completely drain from the cooling system. Close the radiator plug at the bottom of the heater core.

15

Seal the T-tube with the cap supplied with the kit and refill the radiator with coolant or anti-freeze.