First, see if the specification model is suitable. Most agricultural machinery parts and components have specified models and technical parameters. If you purchase electrical equipment, you should check whether the voltage and power of the replaced parts are the same; when purchasing the transmission belt, pay attention to the model and circumference; when purchasing the bearing, pay attention to the bearing type, etc., so as to avoid buying the wrong one. Cause undue losses.

Second, see if the trademark logo is complete. The quality of the outer packaging of the authentic product is good, the writing on the box is clear, the color of the overprint is clear, and the product name, specification model, quantity, registered trademark, factory name and telephone number should be marked on the box and box. Some manufacturers also Make your own mark on the accessories. Some large or important parts are shipped with the instruction manual to guide the user to use the maintenance correctly. When buying, you should recognize it in case you buy fake and shoddy products.

Third, look at the geometric size with or without deformation. Some parts are prone to deformation due to improper manufacturing, transportation, and storage. Pay attention to check whether the geometric size and shape are qualified when purchasing.

Fourth, see if the joint is flat. During the handling and storage of spare parts, burrs, indentations, breakage or cracks may occur due to vibration and bumps, which may affect the use of parts.

5. See if the surface of the part is rusted. The surface of qualified spare parts has certain precision and bright finish. The more important the spare parts are, the higher the degree is, the stricter the anti-rust and anti-corrosion on the packaging. Should pay attention to inspection when purchasing, if the parts are found to have rust spots, mildew spots or rubber cracks, loss of elasticity, or the surface of the journal has obvious turning lines, it should be exchanged.

6. See if the protective surface is intact. Most parts are coated with a protective layer at the factory. For example, the piston nitrate and the bearing bush are protected by paraffin: the piston ring and the surface of the cylinder sleeve are coated with anti-rust oil and wrapped with wrapping paper. If the sealing sleeve is damaged or the wrapping paper is lost during purchase, The rust preventive oil or paraffin is lost and should be returned.

7. See if the glued parts are loose. An assembly made up of two or more parts. The parts are press-fitted, glued or welded. No looseness is allowed between them. For example, the oil pump plunger and the adjustment arm are combined by press-fitting; The clutch is driven and the steel piece is riveted and combined, and the friction piece and the steel piece are riveted or glued. If looseness is found during purchase, it should be exchanged.

Eight, see if the rotating parts are flexible. When purchasing the oil pump and hydraulic pump assembly, turn the pump shaft by hand, feel flexible and free from sticking; when purchasing the fuel injection pump assembly, the plunger should be able to flexibly rotate in the plunger sleeve when the adjustment arm is toggled. When pushing the roller, the plunger should be able to automatically return to the position under the action of the spring.

Nine, see if there are any missing parts in the assembly. When purchasing the fuel injector assembly, check whether the small parts such as the sealing copper pad of the oil return joint and the small steel ball in the tappet are leaked. When purchasing the fuel injection pump assembly, check the plunger sleeve positioning screw seal. And the small parts such as the positioning position of the roller body are missing.