2009 Hummer H3T Owner's Manual - Page 209

Driving Your Vehicle Driving in Water Find out how deep the water is before driving through it. Do not try it if it is deep enough to cover the wheel hubs, axles, or exhaust pipe - you probably will not get through. Deep water can damage the axle and other vehicle parts. The vehicle is capable of depths up to 20 inches (50 cm). Know how to judge whether the water is deeper than this before proceeding into it. If the water is not too deep, drive slowly through it. At faster speeds, water splashes on the ignition system and the vehicle can stall. Stalling can also occur if you get the tailpipe under water. If the tailpipe is under water, you will never be able to start the engine. When going through water, remember that when the brakes get wet, it might take longer to stop. See Driving in Rain and on Wet Roads on page 4-29. 4-27 After Off-Road Driving Remove any brush or debris that has collected on the underbody, chassis, or under the hood. These accumulations can be a fire hazard. After operation in mud or sand, have the brake linings cleaned and checked. These substances can cause glazing and uneven braking. Check the engine and oil coolers for mud accumulation. Thoroughly and carefully clean these devices to allow proper cooling. Check the body structure, steering, suspension, wheels, tires, and exhaust system for damage and check the fuel lines and cooling system for any leakage. The vehicle requires more frequent service due to off-road use. Refer to the Maintenance Schedule for additional information. { CAUTION Driving through rushing water can be dangerous. Deep water can sweep your vehicle downstream and you and your passengers could drown. If it is only shallow water, it can still wash away the ground from under your tires, and you could lose traction and roll the vehicle over. Do not drive through rushing water. Heavy rain can mean flash flooding, and flood waters demand extreme caution.