See Figure 1
Replacing hoses requires draining the cooling system. Have a large drain pan or bucket available along with a generous supply of rags. Be prepared to deal with fluid spills immediately. See the previous list of Do's and Don'ts for other hints.
Drain the cooling system. This is always done with the engine cold. Attempting to drain hot coolant is very foolish; you can be badly scalded.
- Remove the radiator cap.
- Position the drain pan under the drain cock on the bottom of the radiator. Additionally, the Nova/Prizm engines have a drain cock on the side of the engine block, near the oil filter. This may be opened to aid in draining the cooling system. If for some reason the radiator drain cock can't be used, you can loosen and remove the lower radiator hose at its joint to the radiator.
- If the lower hose is to be used as the drain, loosen the clamp on the hose and slide it back so it's out of the way. Gently break the grip of the hose on its fitting by twisting or prying with a suitable tool. Do not exert too much force or you will damage the radiator fitting. As the hose loosens, you can expect a gush of fluid to come out - be ready.
- Remove the hose end from the radiator and direct the hose into the drain pan. You now have fluid running from both the hose and the radiator.
- When the system stops draining, proceed with replacement of the damaged hose.
- Loosen the hose clamps on the damaged hose with a screwdriver and slide the clamps either off the hose altogether or in toward center.
- Break the grip of the hose at both ends by prying it free with a suitable tool or by twisting it with your hand.
- Remove the hose.
- Install a new hose. A small amount of soapy water on the inside of the hose end will ease installation.
Radiator hoses should be routed with no kinks and, when installed, should be in the same position as the original. If other than specified hose is used, make sure it does not rub against either the engine or the frame while the engine is running, as this may wear a hole in the hose. Contact points may be insulated with a piece of sponge or foam; plastic wire ties are particularly handy for this job.
- Slide the hose clamps back into position and retighten. When tightening the clamps, tighten them enough to seal in the coolant but not so much that the clamp cuts into the hose or causes it internal damage. If a clamp shows signs of any damage (bent, too loose, hard to tighten, etc.) now is the time to replace it. A good rule of thumb is that a new hose is always worth new clamps.
Make sure that the hose clamps are beyond the bead and placed in the center of the clamping surface before tightening them.
- Either reinstall the lower radiator hose and secure its clamp or close the drain cocks on the side of the engine block and bottom of the radiator.
- Fill the system with coolant. Chevrolet strongly recommends the coolant mixture be a 50/50 mix of antifreeze and water. This mixture gives best combination of anti-freeze and anti-boil characteristics for year-round driving.
- Replace and tighten the radiator cap. Start the engine and check visually for leaks. Allow the engine to warm up fully and continue to check your work for signs of leakage. A very small leak may not be noticed until the system develops internal pressure.
Leaks at hose ends are generally clamp related and can be cured by snugging the clamp. Larger leaks may require removing the hose again - to do this you MUST WAIT UNTIL THE ENGINE HAS COOLED DOWN, GENERALLY A PERIOD OF HOURS. NEVER UNCAP A HOT RADIATOR. After all leaks are cured, check the coolant level in the radiator (with the engine cold) and top up as necessary.