How to check hoses in cars; replace car hoses

Checking and servicing them. Coolant circulates through hoses to engine, heater, and emission and performance components. At 6-month intervals, check these hoses; if one feels spongy or hard, looks cracked or oily, or is leaking, here’s what to do.

If a coolant hose leaks at a clamp connection, try tightening the clamp. If leaking persists or if it’s a spring wire clamp (which can’t be tightened) the problem is apparently in the hose; replace the hose. Loosen the clamp and move it away from the hose neck.

Pry open the clamp unless it is on the radiator or heater, where prying may damage the neck. Free a spring-wire clamp by using hose-clamp pliers as shown; spray a corroded screw-tower clamp with penetrating oil; replace either with a worm-drive clamp.

If the hose is stuck to a neck, work a thin-bladed screwdriver between the neck and hose. Or slit the hose parallel to the neck and peel off the pieces. Wire brush the neck.

Slide clamps on the new hose, dip the hose ends into antifreeze, then slide the hose on. Center the clamp on the neck. If the neck has a flange, put the clamp against its underside.

Heater hose connections aren’t always accessible at the heater, but you’ll usually find a hose failure close to the engine. Cut the hose a distance away, where it’s good. Install a short new hose that will reach the cut end, and connect the pieces with a flushing T .

There are also vacuum hoses for emission controls. These hoses lack clamps. If such a hose hardens and cracks, a vacuum leak results, possibly affecting engine performance. Check the connections by feel. If a hose is hardened at the neck and is slack, trim it and reconnect it.