How to Flush & Repair a Cooling System
- 1). Let the engine cool completely before touching anything in the cooling system. This can take a few hours. Inspect all the hoses for cracks, leaks or rot. Replace any damaged hoses. Inspect the radiator thoroughly for leaks or rust.
- 2). Apply downward pressure to the radiator cap and twist it off. Consider replacing the radiator if the coolant is milky red and the radiator is rusted through.
- 3). Locate the inlet radiator hose connected to the heater core. It will be connected to the top of the radiator. Cut the hose in half, leaving at least 6 inches on either side to work with. Choose the proper fitting flush tee from the kit. Slide one hose clamp onto each side of the cut hose and install the tee per the instructions on the kit. Tighten the hose clamps 1/4-inch from the tee inlet and screw on the included back-flow prevention accessory.
- 4). Stick the splash deflector into the radiator fill neck until it snaps tight. Install a length of hose or plastic tube (if included) into the splash deflector. Set the other end into a bucket or a proper large disposal container.
- 5). Screw your garden hose onto the back-flow prevention valve. Turn on the engine and let it idle for a few minutes. Turn on the garden hose, taking care to aim the splash deflection system into the bucket. Let the water run for at least 5 minutes. Shut off the engine and hose.
- 6). Remove the garden hose and back-flow prevention coupler from the tee. Remove the splash deflector and insert it into the tee. Aim the hose end into the bucket.
- 7). Refer to the vehicle's owners manual for how much coolant is needed. Calculate half of that (or 70% if you live in a cold climate). Insert a funnel into the radiator fill neck. Pour the calculated amount of new coolant into the funnel. Let the water drain out of the splash deflector hose by aid of gravity.
- 8). Remove the funnel and splash deflector tube from the engine. Screw on the included tee cap. Turn on the engine and let it reach operating temperature. Wearing safety gloves, carefully squeeze and pump the hose connected adjacent to the radiator fill neck, making sure to keep clear of the radiator fan. This procedure removes air from the system. Let the engine run a full 5 minutes after the operating temperature has been reached, then shut the engine off.
- 9). Insert the funnel into the radiator fill neck. Fill the radiator with more coolant until no more will go down. Fill the overflow tank with water/coolant until it reaches the "FULL-HOT" line.
Drive the car for about 15 minutes, keeping a close eye on the temperature gauge. Let the engine fully cool. Check the coolant levels and add more if appropriate. Clean up any spills and dispose of all coolant per local law.