Your heater hoses should be replaced when either of two circumstances occur. The first is that one of the hoses has a leak. If one hose has a leak, you should go ahead and replace them both. The second circumstance is when your hoses are more than five years old, and you are planning a car trip out of town. It is better to replace them than to have a breakdown on a long trip.With over 5 years experience as an auto mechanic, I find that this repair will take between 1 and 3 hours depending on the car and your level of experience.
Your car has two heater hoses.
Both of the hoses are about three or four feet long. They may both be the same diameter, or one might be slightly larger. Determine which hose is being replaced. Or has been previously mentioned, you may elect to replace them both at the same time. This is especially true if you have to remove a lot of items in order to access the hoses.
Remove any parts that block your access to the ends of the heater hoses.
Most of the time, the clamps closest to the front of your car are not too bad to reach. The clamps or fittings near the firewall where the hoses hook to the heater core can be difficult. In fact, I have had times that I cut the hose and put a connector in the hose on my personal vehicles instead of digging through the miscellaneous to reach those fittings.
Remove the clamp that fastens the hose to your engine block.
Generally, these clamps are easy to find and easy to remove with a screwdriver or pliers. Once the clamp is loose, slide it down the hose and pull the hose loose from the block. If it does not come off after a little work. Try making a vertical slit down the hose over the fitting. Use a screwdriver or your knife blade to pry the hose loose from the connector.
Disconnect the hose from the heater core.
There are several different types of clamps that hold the heater hose to your heater core. The easy types have either a screw that you can loosen or a set of “ears” that you can compress with pliers to remove the clamp. Clamps that require some type of compression device to remove can be tricky if you have never used one of these tools. Either way, loosen the clamp and slide it up the hose. Twist the hose until it comes free. You may need to carefully slice it off of the fitting.
Compare the new hose to the old one or take the old one to the parts store to buy a new hose.
After you have removed the hose from the vehicle, compare its length and diameter to the new hose. An inch or so difference in length should not make a difference. However, if it is more than a few inches shorter, there is a good chance that it may not be long enough or may risk being damaged by touching hot engine parts.
Attach the new hose to the engine block and the heater core.
Clean the fittings as much as possible. Slide the clamps onto the new hose. Slip each end onto the fittings on the engine block and near the firewall. Position the clamps on the hose over the fittings and tighten the clamps to secure the hose. Refill the radiator to replace coolant lost during the process. Replace any hardware that was removed during the repair. Drive the car a short distance to warm the engine and check the hose fittings for leaks. Leaks can usually be fixed by tightening the clamp near the leak.