The tow jack is an "emergency companion" in every car's trunk. When encountering situations such as a flat tire or tire blowout, it can help us quickly lift the vehicle to complete tire replacement or simple chassis maintenance. However, if used improperly, it may not only damage the vehicle but also cause serious safety accidents - such as the jack overturning and causing the vehicle to crush and injure people. Therefore, mastering the correct usage method is crucial. Below, we will detail the standardized operating steps and safety precautions.
I. Preliminary preparation: laying a solid foundation for safety 1. Selecting a safe environment - Ground requirements: Operation must be conducted on flat and solid roads (such as cement or asphalt roads), avoiding soft grass, sandy areas, or sloping roads - the latter can easily cause the jack to slip or the vehicle to roll down the slope. - Roadside warning: If changing a tire on the road, turn on the hazard lights and place a warning triangle behind the vehicle (50-100 meters for ordinary roads, more than 150 meters for highways, and even farther for curves) to remind vehicles behind to avoid. - Securing the vehicle: Pull the handbrake to the floor, engage P gear for automatic transmission, or engage 1st gear or reverse gear for manual transmission, to prevent the vehicle from sliding; if there are passengers, it is recommended to get off the vehicle and wait in a safe area.
2. Confirm the support point. The support point of most vehicles is located at the edge of the chassis beneath the door, marked by a raised reinforcement rib (usually indicated by a groove or arrow), or refer to the vehicle manual. It is strictly prohibited to jack up on fragile parts such as plastic bumpers, fuel tanks, and exhaust pipes, as this may cause chassis deformation or oil leakage.
3. Pre-loosen tire screws Before raising the vehicle, use the accompanying wrench to loosen the tire screws counterclockwise (just half a turn to a full turn, do not completely remove them). Reason: When the vehicle is on the ground, the tires do not rotate, making it easier to apply force; if you loosen them after raising the vehicle, the tires will rotate with the screws, making it impossible to remove them.
II. Placing and raising the jack1. Unfold the jack. Take out the jack (usually hydraulic or lever-operated), unfold the folded parts, and adjust the height of the tray to align with the support point. For hydraulic jacks, tighten the pressure relief valve (clockwise) first to prevent oil leakage.
2. Align with the support point. Ensure the jack tray fits perfectly onto the support point without any offset - for example, the circular tray of a hydraulic jack should be secured in the groove of the reinforcing rib to prevent slipping. If there is a gap between the tray and the support point, a small piece of cardboard can be placed underneath (but ensure stability).
3. Slowly raise the vehicle. - Hydraulic type: Press the handle up and down, or rotate the joystick, to slowly raise the jack; - Joystick type: Rotate the joystick clockwise to gradually lift the vehicle.
During the process, closely observe whether the jack is vertical, if the vehicle is shaking, and if the support point is deformed. If any abnormalities are detected (such as the jack being tilted), immediately stop the operation and readjust the position. Stop when the tire is 3-5 centimeters off the ground (just enough for tire changing; if it's too high, it will reduce stability).
III. Using safety stands: the core step of preventing falls. This is the most easily overlooked yet crucial step - do not rely solely on a jack to support the vehicle. If the jack fails, the vehicle could instantly collapse.
Operation method: 1. Take out the safety bracket (metal bar or tripod) that comes with the vehicle and place it in the safety support position of the chassis (adjacent to the jack support point or in the designated area specified in the manual); 2. Slowly lower the jack (by turning the pressure relief valve counterclockwise or using the lever) so that the vehicle weight is fully supported by the safety bracket; 3. Gently shake the vehicle to confirm that the bracket is stable before proceeding with subsequent operations.
IV. Replacing tires or maintenance 1. Remove the old tire Continue to loosen the screws counterclockwise and remove the old tire (if the tire is stuck, gently kick the edge to loosen it).
2. Installing the spare tire Align the spare tire with the bolt holes and manually tighten the screws (clockwise) until they cannot be turned. Note: The screws need to be tightened in a "cross-over sequence" (e.g., if there are five screws, tighten them in a diagonal sequence of 1-3-5-2-4) to avoid uneven stress on the wheel hub and deformation.
3. Pre-tighten the screws. Use a wrench to initially tighten the screws (do not fully tighten them, as they will be finally fixed after the vehicle is on the ground).
V. Lower the vehicle and wrap up 1. Remove the support. Raise the jack again to make the vehicle leave the safety support, remove the support and put it back into the trunk.
2. Lower the vehicle slowly. Turn the pressure relief valve counterclockwise to allow the vehicle to land smoothly. At this point, the tires are fully stressed, and the jack can be removed.
3. Final tightening of screws: Use a wrench to retighten the screws in a crisscross pattern (you can apply additional torque by stepping on the wrench with your body weight) to ensure that the tires are not loose.
4. Tool Storage: Place the jack, old tire, warning triangle, etc. back into the trunk, and check the pressure of the spare tire (emergency narrow tires require a speed limit of 80km/h).
VI. Safety Reminder: These Red Lines Cannot Be Touched 1. No Undercarriage Work: Even with a support, do not work under the vehicle - the support may shift, and the risk still exists; 2. No Overloading: Jacks have a rated load capacity (such as 2 tons or 3 tons), which must match the vehicle's curb weight (check on the door post); 3. Regular Inspection: During each maintenance, check whether the jack's hydraulic oil is leaking, whether the components are rusted, and whether the safety support is intact; 4. Special Surface Treatment: If on muddy/snowy roads, add wooden boards or stones to increase friction to prevent the jack from slipping; 5. Keep Children Away: Ensure that children are not around during operation to avoid accidental contact with the jack.
Summary: The core of using a tow truck jack lies in "slow operation and prioritizing safety". From the initial ground selection to the final screw tightening, every step requires caution. Remember: the safety bracket serves as the ultimate safeguard against falling, and it should never be omitted. Only by adhering to standardized procedures can emergency handling be both efficient and safe.
