How to use the jack correctly for car maintenance?
Jack can be divided into rack jack, screw jack, hydraulic jack and inflatable Jack. The rack jack is more common in the jack equipped with household car, because it has the advantages of light weight, small volume and easy storage. However, due to the limited weight of the support, it is usually equipped with a family car with a dead weight of about 1 ton. " Mr. Jiang, a senior automotive engineer, said that the manufacturer will generally equip a suitable Jack according to the weight of the vehicle. Generally, the jack equipped with car can bear less than 1.5 tons, while the jack equipped with off-road vehicle usually can bear about 2.5 tons due to its heavy weight. Therefore, the jack of small car must not be used for large vehicle, so as to avoid potential safety hazard during vehicle maintenance.
It is understood that at present, a kind of inflatable jack is popular among self driving enthusiasts. It uses the tail gas of the vehicle to inflate the air bag. Generally, the maximum supporting weight of this kind of Jack is about 4 tons, which is suitable for rescue under difficult conditions or self rescue and extrication of off-road vehicles.
Stop the vehicle before using the jack
"If the vehicle is not completely fixed before supporting, it is likely that the vehicle will slide down during the support process. Once the car slides off the jack, the damage to the tools is still the second. If it leads to the injury of the maintenance personnel under the car, it should not be too bad. " Engineer Jiang said.
According to reports, the correct use of the jack requires the car to stop steadily, pull up the hand brake, shift the manual car into the first or reverse gear, and the automatic stop car needs to be put into the P gear. After that, the jack must be used on the hard and flat road. If it is soft ground, such as mud road or sand road surface, it is recommended to use wood or stone pad under the jack before using the jack, so as to reduce the pressure, so as to prevent the jack from falling into the soft ground.
Incorrect support points will damage the chassis
Many car owners have never used or personally replaced the spare tire, nor have they carefully read the introduction of Jack use method and support point in the vehicle manual.
According to reports, there are special support points at the bottom of the car body to support the jack. The support point of the family car is usually on the inside of the side skirt, which is like two fins on both sides of the chassis. It is about 20 cm behind the front wheel and about 20 cm in front of the rear wheel. This fin protrudes from the chassis steel plate and can bear relatively large pressure. If the jack is supported on the steel plate of the chassis, it is likely to cause unnecessary damage to the chassis. In addition, the support on the suspended lower arm is also incorrect operation, if the jack slips and the vehicle falls down, the chassis and Jack will be damaged.