How to buy auto parts

1. See qualified spare parts surface appearance, print or type and legible and formal there are both certain accuracy and polished finish, the more important parts, precision is higher, more rigorous rustproof packaging. When the choose and buy if found auto parts with rust spots or rubber parts cracked, loss of elasticity, or shaft neck surface has obvious tool lines, shall be returned. 
2. The bad work product appearance although on occasion, but due to poor craftsmanship, prone to crack, sand holes, slag inclusion, burr or bruised. Such as cylinder gasket extrusion deformation, when using, easy to cause the untight seal and ablation, lead to the oil, gas leakage and leakage phenomenon. 
3. See "loose" made up of two or more than two parts, accessories parts by being connected, bonding or between welding and become, not allowed to have loose phenomenon. 
4. See assembly mark in order to ensure the parts assembly relations conforms to the technical requirements, with some regular parts surface marker assembly, such as timing gear, piston top marks, such as assembly mark, mark is used to ensure the auto parts suppliers , without a sign or mark fuzzy cannot recognize, will bring great difficulty to assembly, or even wrong. 

5. See gaps complete formal assembly parts must be in good condition, to ensure smooth loading and normal operation. Some assembly of small parts packing, may be a "gray", to cause difficulties for loading. May even for some small auto parts manufacturer parts shortage, cause the whole assembly parts scrap. 
6. The protective layer for the purposes of custody, knock against, prevent parts have protective auto parts production before delivery. Such as piston pin, bearing bush with paraffin wax protection; Piston ring and cylinder liner surface rust-proof oil and paper package; Valve, piston, etc after immersion rust-proof oil encapsulated with plastic bag. When the choose and buy, if find seal set of damage, loss of wrapping paper, rust-proof oil or paraffin loss, shall be returned. 
7. The certificate some important components, especially the assembly class, such as carburetor, distributor, generators, etc., factory generally with manual, certificate of approval, to guide users to install, use and maintenance. 
8. See most auto parts have stipulated specifications and technical parameters. Such as electrical equipment of choose and buy when, should pay attention to check and be in auto parts online of the voltage and power are consistent.