Repair of Cylinder Liner

1. Replacement of wet cylinder liner

Take out the old cylinder liner: When removing the old cylinder liner, gently tap the bottom of the cylinder liner and take it out by hand or with a puller. Metal rust and dirt in the cylinder body should be removed. The junction of the cylinder liner and the cylinder block and the wall of the cylinder block hole in contact with the sealing ring must be smooth to prevent water leakage due to unevenness.

Replacement with new cylinder liner: The cylindricity tolerance of the upper and lower bearing holes of the cylinder block is 0.015mm, and the matching clearance between the bearing hole and the cylinder liner is 0.05~0.15mm. Before installation, the cylinder liner without the sealing ring should be put into the bearing. In the hole, the end face of the cylinder liner should be 0.03~0.24mm higher than the upper plane of the cylinder block when the cylinder liner is compressed, and the difference between the heights of each cylinder is not more than 0.03mm. If it is too high, the upper plane of the cylinder liner can be repaired. Adjustable copper wire under the sleeve flange. When the cylinder liner is pressed in, a new white-painted rubber sealing ring should be installed to prevent water leakage.

Matters needing attention: The cylinder liner does not have much force when it is pressed, and the inner diameter of the cylinder liner is less affected, so it is usually not polished; Out the cylinder liner, check and trim the rusted part of the bearing hole. After the cylinder liner is pressed in, the sealing ring must not be deformed, and it should be well sealed. If necessary, perform a hydraulic test to ensure that there is no leakage.

2. Mounting of dry cylinder liner

Select the cylinder liner: The outer surface roughness of the cylinder liner should not exceed Ra0. 80μm; the cylindricity tolerance should not exceed 0.02mm; the outer edge of the lower end of the cylinder liner should have a chamfer of 3X 15 or 10X45'.
Take out the old cylinder liner: The old cylinder liner can be pulled out with a special tool or bored with a cylinder boring machine. After the old cylinder liner is taken out, it should be checked whether the bearing hole of the cylinder liner meets the requirements. There should be an appropriate amount of interference between the cylinder liner and the bearing hole. Generally, the interference between the engine cylinder liner and the cylinder hole is 0.05~0.08mm.

Press-in of new cylinder liner: After cleaning the cylinder and cylinder liner, coat the outer wall of the cylinder liner with oil, insert the cylinder to align it with a square ruler, and press in with a press or special tool. In order to prevent deformation, it should be pressed into the cylinder. Coat the inner surface of each cylinder hole with Loctite 620 glue; press the cylinder liner (outer diameter reduced by 0.05∞007mm) into the cylinder hole; Full mouth contact.

Damaged trimming plane: After the cylinder liner is pressed into the bearing hole, its end face should be flush with the upper plane of the cylinder block. If it is higher than the plane of the cylinder block, it can be trimmed with a file. If the flange groove is deep, copper wire can be placed under the flange.