Like any liquid-cooled automobile engine, the radiator in the 1997 Chevy Venture minivan transfers heat that has been absorbed by the coolant in the engine to the outside air. If the radiator becomes clogged or develops a leak it must be replaced to restore proper cooling and prevent engine overheating. The 3.1-liter and 3.4-liter aluminum engines found in the Venture are very susceptible to damage when overheated, so proper cooling system function is critical to engine life.
Allow the engine to cool fully before carefully removing the radiator cap and draining the cooling system. This will prevent serious burns. While facing the front of the Venture, slide a drain pan under the right side (driver side) of the van below the radiator. Open the drain valve located on the bottom of the radiator by twisting the thumbscrew clockwise to let the coolant drain from the radiator. Remove the radiator cap from the top left of the radiator and allow the coolant to drain from the system completely. Close the drain valve.
Remove the 10-millimeter bolts that attach the coolant reservoir to the driver-side frame brace. Unplug the small rubber coolant hose from the reservoir and lift the reservoir from the engine compartment. Remove the 13-millimeter bolts from both frame braces using a socket and ratchet and lay the braces aside. Remove the two upper engine mount brackets that are attached to the top of the radiator core support using a 15-millimeter socket and ratchet.
Check the radiator hoses for cracks or soft spots indicating that they need replacement. Disconnect the upper radiator hose from the radiator. Using a hose clamp pliers, compress the spring-loaded hose clamp and slide it down the hose, then twist the hose and pull it free from the radiator. If the hoses are bonded to the radiator they may need to be cut off and replaced. Replace hoses that are damaged or worn as needed.
Remove the cooling fan using a 10-millimeter socket and ratchet to remove the four mounting bolts. Unplug the electrical connector from the fan motor and lift the fan up and out of the engine compartment.
Pull the transmission dipstick out of the dipstick tube located near the passenger side of the fire wall and check the fluid for water contamination caused by a ruptured transmission cooler inside the radiator. This will show up as a milky colored residue on the stick. Replace the transmission fluid and filter if this occurs. Remove the transmission lines on the left side of the radiator by using a small pick to remove the retaining clips on the fittings. Be careful when removing the retaining clips, which have a tendency to fly off the fitting as they are removed. Replacements are hard to find. Pull the lines out of the fittings.
Remove the lower hose in the same manner as the upper hose was removed. Remove the two radiator mounts on top of the radiator using a 10-millimeter socket and ratchet.
Lift the radiator from the engine compartment. Transfer the lower radiator mount bushings and transmission line fittings from the old radiator to the new one. Slide the new radiator into place in the engine compartment.
Attach the lower radiator hose and radiator mounts. Compress the lower radiator hose clamp using the hose clamp pliers and slide it into position on the hose. Reinstall the cooling fan, transmission lines and upper hose.
Reinstall the motor mount brackets, the frame braces and the coolant reservoir. Fill the new radiator with a 50/50 mix of fresh coolant and water by pouring it into the radiator cap opening. Fill the coolant reservoir up to the full level marked on the reservoir.
Open the two air bleed screws located on the thermostat housing and on the tube attached to the back of the water pump housing. Continue to add coolant until coolant comes out of the air bleed screws to remove air from the cooling system. Close the screws. Test drive the van to verify that it doesn't overheat. It may be necessary to bleed the air out one more time after the test drive.
