How to Replace the Water Hoses in a Pontiac Grand Prix

Buy preformed hoses that fit your Pontiac Grand Prix at your local auto parts store. Gates brand items #22814 (upper) and #22373 (lower) fit the Grand Prix. Ask for a comparable hose 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 a tension spring clamp and move it to an area of the hose that is more pliable and out of the way.

Mark where the old hose came to on the machinery so that you can put the replacement up the same amount and avoid leakage. Take a digital picture of the original placement so it's easy to replicate.

Pull the hose away from the car parts. If it is stuck, slit the hose downward a couple of inches below the insertion point and peel it away as needed. Use a piece of coarse sandpaper to clean the area where the hose was stuck to the automobile part. Clean the other connection areas while they are free.

Place a container below the radiator to catch the coolant mixture so that it doesn't go into the storm drains and thus the groundwater. Jack up the Pontiac Grand Prix and put jack stands in place.

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 of the used hoses and clamps. Sand the areas where the old hose met the Pontiac Grand Prix 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 Pontiac Grand Prix 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 the screw on each clamp.

Repeat the above step for the clamps and connect the 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 screw.

Reuse the original coolant if it's still clean. Fill the radiator the rest of the way with a 50/50 combination of coolant and water to the cap line. Refill it more as it goes down into the radiator. Do this until it stops percolating and making room for more coolant.

Start the engine with the radiator cap still open. The thermostat will get warmer, and the fluid will drop as the coolant begins to circulate. From here, you can finish filling up the radiator. Adjust the radiator cap and fill up the overflow reservoir to the line that is marked "full."

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.