2026-05-18 <<
1. Check whether the trademark logo is complete. Genuine products have good quality outer packaging, with clear handwriting and vivid color printing on the packaging box. The packaging box and bag should be marked with the product name, specifications and models, quantity, registered trademark, factory name and address, telephone number, etc. Some manufacturers also print their own marks on the accessories. Some important parts such as generators, distributors, fuel injection pumps, etc., are also equipped with user manuals, certificates of conformity, and inspector stamps to guide users in proper use and maintenance. When purchasing, you should carefully identify them to prevent buying counterfeit and inferior products.
II. Check for any deformation in geometric dimensions. Some parts are prone to deformation due to improper manufacturing, transportation, and storage. During inspection, roll the shaft parts along a glass plate to see if there is any light leakage at the joint between the part and the glass plate to determine whether it is bent. When purchasing clutch driven plate steel sheets or friction plates, hold the steel sheets and friction plates up to your eyes to observe whether they are warped. When purchasing oil seals, the end face of the oil seal with a frame should be perfectly round and able to fit with flat glass without any flexing. The outer edge of the oil seal without a frame should be straight and upright. When holding it with your hand, it should deform, but it should return to its original shape after being released. When purchasing various types of gaskets, attention should also be paid to checking the geometric dimensions and shape.
Third, check whether the joint parts are flat. During the handling and storage of spare parts, burrs, indentations, damages, or cracks often occur at the joint parts due to vibration and bumping, affecting the use of the parts. Attention should be paid to inspection when purchasing.
Fourth, inspect the surface of the parts for rust. Qualified spare parts have both precision and a shiny finish. The more important the spare parts are, the higher the precision, and the stricter the packaging for rust and corrosion prevention. When purchasing, attention should be paid to inspection. If rust spots, mold spots, or cracks and loss of elasticity are found on rubber parts, or if there are obvious tool marks on the surface of the shaft neck, they should be replaced.
5. Check whether the protective coating is intact. Most parts are coated with protective layers before leaving the factory. For example, piston pins and bearing shells are protected with paraffin wax; piston rings and cylinder liners are coated with anti-rust oil and wrapped with packaging paper; valves, pistons, etc. are immersed in anti-rust oil and sealed with plastic bags. If the sealing sleeve is damaged, the packaging paper is missing, or the anti-rust oil or paraffin wax is lost during purchase, it should be returned or replaced.
VI. Check whether the bonded parts are loose. For accessories composed of two or more parts, the parts are connected through press fitting, bonding, or welding, and there should be no looseness between them. For example, the oil pump plunger and the adjustment arm are assembled through press fitting; the clutch driven wheel and the steel plate are riveted together, and the friction plate and the steel plate are riveted or bonded; the paper filter element frame and the filter paper are bonded together; the wire ends of electrical equipment are welded together. If any looseness is found during purchase, it should be replaced.
7. Check whether the rotating parts are flexible. When purchasing rotating component assemblies such as oil pumps, rotate the pump shaft by hand and ensure it feels smooth and free of any clamping stagnation. When purchasing rolling bearings, support the inner ring of the bearing with one hand and rotate the outer ring with the other. The outer ring should rotate quickly and freely, then gradually slow down. If the rotating parts are not rotating smoothly, it indicates internal corrosion or deformation, and it should not be purchased.
8. Check whether there are any missing parts in the assembly components. Regular assembly components must be complete and intact to ensure smooth assembly and normal operation. If individual small parts on some assembly components are omitted, the assembly components will fail to work or even become obsolete.
