Most auto parts have specified the type and technical specifications. Such as the purchase of electrical equipment, should be careful to check with the replacement parts for voltage, power are the same; the purchase of the belt, should pay attention to the model and perimeter.
Look trademarks are complete
Good quality authentic product packaging, the packaging writing clear, bright color overprint. Some important components such as generators, distributor, fuel pump, etc., comes with instruction manual, certificate and inspectors chapters to guide users to the proper use and maintenance. Purchase should be careful to recognize, avoid buying a fake and shoddy products.
Look geometry without deformation
Some parts due to manufacturing, transportation, improper storage, easy to produce deformation. Check when the shaft parts can scroll along the glass circle, look at the parts and glass bonded to determine whether the presence or absence of light leakage bent; optional or friction clutch plate steel sheet, can be steel, friction sheet held in front observe whether warp; in the purchase of oil seal, seal end face with a skeleton should positively circular, flat glass bonding with no warping; skeleton oil seal outer edge should be straight, with a deformed hand After restitution should be able to let go. In the purchase of all kinds of gaskets should also be careful to check the geometry and shape.
See whether the formation of binding sites
Parts in the handling, storage process, due to vibration, bump, often produce glitches in the binding site, indentation, breakage or cracking, affecting parts. Purchase should pay attention to check.
See whether the parts of the surface rust
Qualified Parts surface, both have a certain precision burnished finish, the more important parts, the higher the accuracy, the more stringent packaging rust and corrosion. Purchase should pay attention to check, if found parts have corrosion spots, mildew spots or pieces of rubber cracking, loss of elasticity, or journal surface obviously turning lines, should be reversed.
Look protective surface layer is intact
Most parts in the factory are coated with a protective layer. As the piston pin, bearing with paraffin protection; piston rings, cylinder coated with anti-rust oil and wrapped with wrapping paper; valves, pistons and other after-rust oil dip with a plastic bag package. When you purchase if found damaged glands, wrapping paper loss, anti-rust oil or paraffin loss, it should be returned.
Look for loose parts glued
By a combination of two or more parts into parts, by press-fit between the parts, gluing or welding molding process, there are loose between them is not allowed, such as the pump plunger and the adjustable arm is fitted by press combination ; the clutch Yi and steel is a combination of riveting, friction plate and steel is riveted or glued; the paper filter cartridge and filter paper is glued skeleton made; thread is welded electrical equipment a. If there is loose, the purchase should be reversed.
Look rotating parts are flexible
When you purchase machine pumps and other rotating parts assembly, rotate the shaft by hand, should feel flexible cable wiring; the purchase of rolling bearing, single-handedly support the bearing inner ring, an outer ring spun the other hand, the outer ring should be able to quickly rotate freely, then gradually stopped. If the rotating member rotation not working, the internal corrosion or deformation not to buy.
Look assembly parts for missing parts
Regular assembly member must complete and intact, in order to ensure a smooth assembly and running. Some individual small parts assembly member mounted on if the leak will make assembly parts can not work or even scrapped.
See assembly mark is clear
To ensure the assembly relationship fittings meet the technical requirements, and in some parts (such as the timing gear) surface engraved with the assembly mark. If there is no sign or symbol fuzzy illegible, assembly will bring great difficulties, even installed wrong.
Look mating surface for wear
If there are signs of wear parts with the surface, or the surface of the paint after painting accessories poke find old paint, is mostly used camouflage pieces, then returned on request.
See whether the target surface hardness
Each fitting has a surface hardness requirement specified in the purchase and the merchant to determine the proper quotient, the available hacksaw stubble to test plans, no scratches when slipping plan, indicating high hardness; slight superficial scar after stroke high hardness; there are obvious signs of post-stroke, indicating low hardness Face careful not to damage when test program.
