1. Check whether the joint is smooth. During the transportation and storage of spare parts, due to vibration and collision, burr, indentation and breakage often occur at the joint part
Damage or crack, affecting the use of parts. Pay attention to check when purchasing.
2. Check whether the trademark is complete. The outer packing quality of authentic products is good, the handwriting on the packing box is clear and the overprint color is bright. The packing box and bag should be marked with the product name, specification and model, quantity, registered trademark, factory name, address and telephone number, etc. some manufacturers also make their own marks on the accessories. Some important parts, such as generator, distributor, fuel injection pump, etc., are also equipped with instruction manual, certificate and inspector’s seal to guide users to use and maintain correctly. When purchasing, you should recognize it carefully to avoid buying fake and inferior products,
3. Check whether the rotating parts are flexible. When purchasing the oil pump and other rotating parts assembly, rotate the pump shaft by hand, which should be flexible and free of stagnation. When purchasing rolling bearings, support the inner bearing ring with one hand and rotate the outer ring with the other hand. The outer ring should be able to rotate quickly and freely, and then stop rotating gradually. If the rotating parts do not work well, it means that the internal corrosion or deformation, do not buy.
4. Check whether the protective surface is in good condition. Most parts are coated with protective coating at the factory. For example, the piston pin and bearing bush are protected by paraffin wax; the surface of piston ring and cylinder liner is coated with antirust oil, and the valve and piston are wrapped with wrapping paper and sealed with plastic bags after being immersed in antirust oil. If the seal sleeve is damaged, the packing paper is lost, antirust oil or paraffin is lost, it should be returned and replaced.
5. Check the geometric dimension for deformation. Some parts are easy to deform due to improper manufacturing, transportation and storage. When checking, the shaft parts can be rolled around the glass plate to see whether there is light leakage at the joint between the parts and the glass plate to judge whether it is bent; when purchasing the steel plate or friction plate of the clutch driven plate, you can hold the steel plate and friction plate in front of your eyes to observe whether it is warped. When purchasing the oil seal, the end face of the oil seal with framework should be round, which can fit with the flat glass without bending; The outer edge of the frameless oil seal should be straight and deformed by hand. It should be able to return to its original state after releasing it. In the purchase of various types of pads, should also pay attention to check the geometric size and shape
6. Check whether the assembly parts are missing. Normal assembly parts must be complete and intact to ensure smooth assembly and normal operation. If some small parts on some assembly parts are missing, the assembly parts will not work or even be scrapped.
7. Check whether the surface of parts is rusted. The surface of qualified spare parts has both a certain precision and a smooth finish. The more important the spare parts are, the higher the precision is, and the more strict the anti rust and anti-corrosion packaging is. Pay attention to check when purchasing. If the parts are found to have rust spots, mildew spots or rubber parts are cracked and lose elasticity, or there are obvious turning tool lines on the journal surface, they should be replaced
8. Check whether the bonding parts are loose. For accessories composed of two or more parts, the parts are pressed, glued or welded, and no looseness is allowed between them. For example, the oil pump plunger and the regulating arm are assembled by pressing, the clutch driven wheel and the steel plate are riveted, the friction plate and the steel plate are riveted or glued; the paper filter element framework is glued to the filter paper; The wire ends of electrical equipment are welded. If any looseness is found during purchase, it s
Post time: Oct-14-2020