Everything You Need to Know About the 1421DH55 Swing Gearbox by Kyotechs

Possible internal component wear, clogged filter, oil contamination, or insufficient system pressure.

Solution: Replace worn components, clean or replace filter, replace hydraulic oil, check and adjust system pressure.

Possible loose connections, damaged wiring, or sensor failure.

Solution: Tighten connections, repair wiring, replace faulty sensors.

Reasons from the piston group
1. The piston ring gap is too small. If the opening gap, side gap or back gap of the piston ring is too small, the piston ring will be stuck due to heat expansion when the engine is working, and it will be pressed tightly against the cylinder wall, or the piston ring will be broken, which can easily pull out grooves on the cylinder wall.
2. The piston pin is out. Because the piston pin retaining ring is not installed or falls off or breaks, the piston pin will be out during movement, which can easily damage the inner wall of the cylinder and cause the cylinder to blow into the crankcase.
3. The piston cylinder gap is too small or too large. If the piston material is poor, the manufacturing size error is too large, or the piston is deformed after the piston pin is assembled, the matching gap between the piston and the cylinder is too small, and the piston is stuck after heat expansion, which will then damage the cylinder wall.
4. The piston ring is seriously carbonized. Excessive carbon deposits cause the piston ring to stick or bite in the ring groove. At the same time, carbon deposits are a hard abrasive that will grind into longitudinal grooves on the cylinder wall.
5. The piston is seriously off-cylinder. Due to the bending and twisting of the connecting rod, the parallelism and coaxiality deviations of the connecting rod journal, main journal, and piston pin seat are too large, causing the piston to be significantly off-cylinder, which will accelerate the wear of the piston ring, piston and cylinder wall and destroy the formation of the oil film.

Reasons for cylinder sleeves
1. The roundness and cylindricality tolerances of the cylinder sleeves exceed the allowable range, which greatly reduces the sealing of the piston and cylinder sleeves. The high-temperature gas in the cylinder flows down, destroying the oil film between the piston and the cylinder wall, and then causing cylinder pulling.
2. The cylinder sleeve is deformed during the assembly process. For example: the protrusion of the upper end surface of the cylinder sleeve is too large, and the cylinder sleeve is deformed after the cylinder head is installed; the cylinder sleeve water blocking ring is too thick, and the cylinder sleeve is deformed after being pressed into the body, which can easily cause cylinder pulling.

Reasons for use:
1. Whether the size of the cylinder sleeve used during assembly does not match the cylinder body and piston.
2. The air filter is not sealed, which makes the filtering effect worse. Dust, sand and other impurities in the air are sucked into the cylinder, forming abrasive wear. Tests show that if a few grams of dust are sucked in every day, the wear of the cylinder liner will increase by more than 10 times.

Check the battery charge and connections, inspect the starter motor and ignition system, ensure the fuel system is supplying fuel properly, and read fault codes for further diagnostics.

1. When walking on the construction site, please try to place the travel motor behind the walking to reduce the squeezing of the sprocket.

2. The continuous walking time of the machine cannot exceed 2 hours. The walking time on the construction site should be minimized. If necessary, it is recommended to walk after a short stop in the middle.

3. Avoid raised hard objects when walking to avoid stress concentration on the track chain.

4. Confirm the tightness of the crawler, adjust the crawler tighter in soft places such as soil, and adjust the crawler looser when walking on stones. It is not good to have a crawler that is too loose or too tight. Too loose will cause the crawler to derail easily, and too tight will cause the chain sleeve to wear too quickly.

5. Check whether there are foreign objects such as stones in the crawler frequently, and clean them if there are.

6. When working on a muddy construction site, it is necessary to frequently idle to discharge the soil deposited in the crawler.

7. Try to avoid the excavator turning in circles on the spot.

8. Regularly check the rail guard and the rail guard welded under the guide wheel.