Hoses should be inspected at least once a month for cracks, swelling and softness. When inspecting hoses, be sure to check the bottom radiator hose, as this one can be easily overlooked. Since the hoses are generally the weakest link in the cooling system, always inspect them before going on a long trip and at the onset of cold or hot weather. The hoses to and from the radiator are the most visible, but there are also other water hoses under the hood, notably the heater hoses running to the firewall. Check these hoses at the same time you check the radiator hoses.
REMOVAL & INSTALLATION
See Figure 1
Replacing hoses requires draining the cooling system. This potentially messy job involves working under the car and handling antifreeze, a slippery, smelly, stain-making chemical. Have a large drain pan or bucket available along with healthy 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 point where the lower radiator hose to the radiator. Loosen the clamp on the hose and slide it back so it is 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 removal of the hose.
- Loosen the hose clamps with a screwdriver and slide the clamps either off the hose altogether or in toward the 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.
- Clean the hose fitting of any material or other deposits.
- Install a new, or if reusable, the old 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.
- Reinstall the lower radiator hose and secure its clamp.
- Fill the system with coolant. Volvo 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.
- 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.