‘Why is my radiator hose collapsing?’

The Car Doc weighs in.

2011 Chevrolet Tahoe LTZ.
2011 Chevrolet Tahoe LTZ. –Chevrolet

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Q. I replaced the thermostat and upper radiator hose in my Chevrolet Tahoe because the hose was collapsing. I flushed out the radiator and changed the hose and thermostat. The hose still collapses, though. The truck otherwise seems fine. Could this be a head gasket issue?

A. More than likely, the problem is as simple as a malfunctioning radiator cap. In addition to pressuring the cooling system, the radiator cap allows the coolant to flow into the overflow tank. As the pressure in the system drops — when the engine is off and cooling down — the pressure cap allows the excess coolant in the overflow tank to return to the radiator. If the radiator cap is malfunctioning, the vacuum created in the system will collapse the hose.

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John Paul is AAA Northeast’s Car Doctor. He has over 40 years experience in the automotive business and is an ASE certified master technician. Email your car question to jpaul@aaanortheast.com.