How to Replace the Water Hoses in a Toyota Tundra

Choose the hoses that fit your Toyota Tundra at your local auto parts store. Consider Gates brand of preformed hoses, items #21660 (upper) and #23018 (lower), or comparable hoses if that brand is out of stock.

Loosen the old clamps by turning the tension-controlling screw left with a flathead screwdriver. Move it down the hose and out of the way. Use a pair of pliers to squeeze the tension spring clamp and move it to a more pliable area of the hose so it's out of the way.

Mark how high the old hose came on the machinery so you can put the replacement up the same amount and avoid leakage. Take a digital picture of the original placement so you can replicate it.

Pull the hose away from the Toyota Tundra. If it's stuck, slit the hose downward a couple of inches below the insertion point and peel it away. Use a piece of coarse sandpaper to clean the area where the hose was stuck to the truck. Clean the other connection areas while they're free.

Position a container below the radiator to catch the coolant mixture so it doesn't go into the storm drains and thus the groundwater. Jack up the Toyota Tundra one side at a time, put jack stands in place and let the truck down on the stands.

Open the drain plug or remove the bottom radiator hose to drain. Remove the top hose by slipping it off the radiator shroud at one end and the thermostat housing at the other. Discard all used hoses and clamps. Sand the areas where the old hose met the Toyota Tundra parts to remove pieces of hose and other grit.

Use adjustable clamps with screws for greater protection in holding the new hoses in place. Install the new Toyota Tundra hoses by reversing the steps you went through when removing the old ones.

Place the clamps on the top hose and slide them toward the middle. Push the hose securely onto the top opening in the radiator shroud at one end and the thermostat housing (at the top of the water pump) on the other. Tighten each clamp by tightening the screw.

Repeat the above step for the clamps and connect the next hose to the bottom radiator shroud at one end and the bottom of the engine at the other. Adjust clamps into place and tighten the screws. Close the radiator drain plug, if applicable.

Fill the radiator with a 50/50 combination of coolant and water to the cap line. Add more as it goes down into the radiator. Do this until it stops percolating and making room for more coolant.

Start the Toyota Tundra's engine with the radiator cap still off. The thermostat will get warmer, and the fluid will drop as the coolant begins to circulate. Finish filling up the radiator as needed, put the radiator cap back on and fill the overflow reservoir to the "full" line.

Check to see that the temperature gauge is no higher than before. Verify the drain plug is closed and there are no leaks at the hose connections or anywhere else.