The upper and lower radiator hoses along with all heater hoses should be checked for deterioration, leaks (hoses sometime swell up before breaking) and loose hose clamps every 15,000 miles (24,000 km) or 1 year. Replace the hose clamps when replacing the radiator or heater hose.
REMOVAL & INSTALLATION
See Figure 1
Drain the cooling system. This is always done with the engine COLD. Follow this service procedure:
- Remove the radiator cap.
- Position a pan under the drain cock on the bottom of the radiator. Additionally, some engines have a drain plug 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. 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 at each end of the hose to be removed.
- Working the hose back and forth, slide it off its connection remove the old hose. Install the new hose as needed. A small amount of light grease or coolant on the inside of the hose end will ease installation.
Radiator and heater 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.
- Position the new hose clamps at least 1 / 4 in. (6mm) or more from the end of the hose and tighten them. Make sure that the hose clamps are beyond the raised bead of the tube and placed in the center of the clamping surface before tightening them.
- Fill the system with coolant. Toyota strongly recommends the coolant mixture be a 50-50 mix of antifreeze and water. This mixture gives best combination of antifreeze and anti-boil characteristics for year-round driving.
- Install 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 slightly. Larger leaks may require removing the hose, and again to do this, YOU MUST WAIT UNTIL THE ENGINE HAS COOLED DOWN. NEVER UNCAP A HOT RADIATOR! After all leaks are cured, check the coolant level in the radiator (with the engine cold) and fill the coolant level as necessary.