A: ①The shape tolerance of the cylinder liner should reach the technical standard;
②The internal and external surface roughness should meet the original factory regulations
③No defects such as cracks, looseness, blisters, burrs, etc. are allowed on the working surface of the cylinder liner
④After the cylinders are placed in the cylinder block, they must pass the hydrostatic test. Under the corresponding pressure, no water leakage or water seepage is allowed within 5 minutes.