Q: What Causes Engine Hoses to Leak?

Hose leaks are caused by a variety of issues.

The first of these issues is, of course, normal aging. As the hose material ages, it becomes weaker. The hose has been subjected to innumerable thermal cycles (heat up and cool down) which causes the rubber to weaken and wear out. Also, the coolant becomes contaminated with rust particles, rubber that has sloughed off the lining of the hose, and silica that has been washed out of tiny crevices of the engine from the manufacturing process.

The next cause is chafing of the hose. During normal operation of the engine, the hoses may rub against a bracket, a stationary component, or a belt may rub against the hose. This seriously degrades the strength of the hose and significantly lessens the hose’s life span. This leads to an eventual rupture of the hose.

Another cause of leaking hoses are loose hose clamps. Hose clamps provide the mechanical means of fastening a hose to a hose connection on the engine or the radiator. If a hose clamp is loose, the pressure inside the cooling system will force coolant out between the hose and the connector, resulting in a hose that gets blown off of the engine.

If you need any help with a leaking hose, reach out to a certified mechanic who can inspect your hoses for proper function. The mechanic will ensure that they are routed away from any other components so as not to chafe, the hose clamps are installed properly and are tight, and that the coolant is at the proper level and still contains the necessary additives at the correct strength to protect the engine.