Coolant Hoses & Clamps

Coolant hoses and clamps are a big part of the cooling system, because without the hoses themselves, the coolant would not be able to flow to and through all the major components of the cooling system. Often times, coolant leaks can be caused by something as simple as a loose or worn clamp. Other times a coolant hose could be the cause of a leak from either a pinhole or a rupture in the hose.

There are several types of coolant hoses, such as heater hoses, radiator hoses, bypass hoses and coolant reservoir hoses.

Radiators contain an upper and a lower radiator hose used to direct the coolant to and from the engine. One of the radiator hoses, sometimes the upper or sometimes the lower, depending on the flow of the coolant system, leads to the thermostat, while the other hose has the coolant directed back to the radiator from the water pump.

Heater hoses are part of the coolant system that have an inlet hose leading to the heater core and an outlet hose returning from the heater core heading to the intake manifold. The main purpose of the heater hoses is to direct hot antifreeze through the heater core so the main heater inside the vehicle will function at its peak temperature.

Bypass hoses are routed from the engine side of the thermostat to the inlet side of the water pump. Bypass hoses are used so that the coolant can continue to flow whether the thermostat is opened or closed. This continuous flow prevents any excessive pressure from building in the coolant system, which could contribute to overheating.

There are two types of clamps that you may find on coolant hoses. Hoses can either use aftermarket clamps that can be tightened by use of a screwdriver or a small ¼ inch socket and ratchet, or original equipment (which are clamps from the vehicle manufacturer) clamps that are self-tightening.

Any coolant leak from a hose or a clamp should be investigated and fixed immediately, because the coolant system is under pressure and loss of that pressure will result in overheating--putting more strain on your engine.

Something as simple as a clamp could also be a contributor to a leak. Aftermarket clamps tend to loosen up over time and just need to be retightened or replaced. Over tightening aftermarket hose clamps can cause the threads to slip, loosening the clamp. Original equipment clamps may need to be replaced because they can become weak and lose their spring action, causing a coolant leak.

Besides coolant system leaks, pressing a coolant hose with your hand to feel how soft the hose is, can oftentimes determine if the hose is in need of replacement. Hoses wear from the inside out due to the hot coolant that travels through the hose; so feeling the hose to determine whether it is abnormally soft is a great preventative maintenance check and can save you from getting a split or burst hose.

Always begin by performing the preliminary coolant inspection so that a coolant component leak or a hose and clamp leak is not overlooked. It can be quite easy to break off the nipple that the hose slips over, especially if the nipple is small in diameter, so the following steps will show you the proper technique to use when removing and installing coolant hoses and clamps.