Heater hoses are rubber hoses found on virtually all vehicles equipped with internal combustion engines. Their main purpose is to transport coolant from the engine to the heater core located inside of the vehicle. They are often premolded into specific shapes, or cut to specific lengths in order to accommodate the setup of the vehicle’s cooling system. They are usually located at the rear of the engine, near the firewall, connected to the heater core outlets, or the heater control valve. Automotive cooling system hoses are made of heavy duty materials, and are designed to withstand exposure to the heat and chemicals of the engine’s coolant. Over time, however, they can wear out, leak, and begin to have issues. Usually a bad or failing heater hose will produce a few symptoms that can alert the driver of a potential issue.
1. Cracked hoses
One of the first visible symptoms of an issue with the heater hoses is visibly dry, or cracked hoses. As the vehicle approaches high mileage the coolant hoses will eventually begin to wear, dry, and may eventually crack. Hoses that are visibly cracked will be structurally weakened and may be more prone to coolant leaks. Visibly cracked hoses should be replaced if possible, to prevent them from possibly leaking.
2. Coolant leaks
One of the first symptoms of a an issue with the vehicle’s heater hoses is coolant leaks. The heater hoses are designed to be resistant to coolant and heat, however over time they can eventually wear out. Old hoses can break down, weaken, and eventually rupture and leak. A leaking heater hose will not only produce a coolant leak that may leave puddles of coolant under the vehicle. If left unattended coolant leaks can eventually progress into more serious issues.
3. Engine overheating
Another symptom of an issue with heater hoses is engine overheating. If the heater hoses leak enough, the coolant loss will compromise the effectiveness of the cooling system and cause the vehicle to overheat. Any issues that cause engine overheating should be addressed as soon as possible to avoid the potential of serious engine damage occurring.
Usually heater hoses will begin to show signs of visible exterior wear long before they leak, however this is not always the case. If you suspect that your vehicle’s heater hoses may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the hoses should be replaced.
This article originally appeared on YourMechanic.com as Symptoms of Bad or Failing Heater Hoses and was authored by Eduardo Ruelas.