2008 Jeep Grand Cherokee Owner's Manual - Page 412

412 MAINTAINING YOUR VEHICLE • Make sure that the radiator and coolant recovery bottle hoses are not kinked or obstructed. • Keep the front of the radiator clean. If your vehicle is equipped with air conditioning, keep the front of the condenser clean, also. • Do not change the thermostat for summer or winter operation. If replacement is ever necessary, install ONLY the correct type thermostat. Other designs may result in unsatisfactory cooling performance, poor gas mileage, and increased emissions. Hoses and Vacuum/Vapor Harnesses Inspect surfaces of hoses and nylon tubing for evidence of heat and mechanical damage. Hard or soft spots, brittle rubber, cracking, tears, cuts, abrasions, and excessive swelling indicate deterioration of the rubber. Pay particular attention to the hoses nearest to high heat sources such as the exhaust manifold. Inspect hose routing to be sure hoses do not touch any heat source or moving component that may cause heat damage or mechanical wear. Insure nylon tubing in these areas has not melted or collapsed. Inspect all hose connections such as clamps and couplings to make sure they are secure and no leaks are present. Components should be replaced immediately if there is any evidence of degradation that could cause failure. Fuel System Connections Electronic Fuel Injection high pressure fuel systems are designed with tubes and special connects, connections and clamps which have unique material characteristics to provide adequate sealing and resist attack by deteriorated gasoline.