How to quickly replace excavator oil seal

The replacement of the oil seal in the central swivel joint on the excavator and the oil seal in the boom cylinder, such as the traditional method, is time-consuming and laborious, and limited by the site and equipment, it cannot be quickly replaced and repaired in the field. In practice, a set of quick methods for this type of oil seal can be found, which can increase the work efficiency by 15-20 times.

1.Replacement of oil seal of central rotary joint

(1) First, unscrew the related fixing screws, and then drag the lower transmission box with a liftable hydraulic trolley, and rotate it to a certain angle, then lower the trolley and pull the lower transmission box to one side.

(2) Cut off the oil return pipe with an oil breaker (so as not to draw out a large amount of hydraulic oil along the core of the central rotary joint). Unscrew the 4 fixing screws on the oil distribution pan.

(3) Hang the iron hooks on both sides of the tensioner on the two symmetrical tubing joints on both sides of the core; then use a jack to hold the vertical drive shaft, and the core can be pulled out while the jack is raised, and the one on it can be replaced. The oil is sealed.

(4) Use the top sleeve to drag the core of the central rotary joint, and then use a 1.5t jack to push the core back to its original position, and install the other parts in the reverse order of disassembly.

The whole process only needs to be operated by one person (also can work together), without dismantling any oil pipe. The liftable hydraulic trolley can be retrofitted with a horizontal jack, or an existing trolley can be used, while the oil cut-off device can be replaced by a fire-fill glue clip. The tensioner can be self-made. It is mainly composed of a bottom plate and an adjustable iron chain. The jack can be completed. The whole operation does not require other auxiliary equipment, and the tools used are also very simple, which is especially suitable for quick repairs in the field.

2.Replacement of the oil seal of the boom cylinder

The boom cylinder oil is heavy, and the replacement of the oil seal can be completed in a relatively short time if it is carried out in a qualified repair shop. However, in the field, it is quite difficult for one person to work without lifting equipment. . The method I summarized only needs 1 chain hoist, 4 wire ropes of varying lengths, and other related tools. The specific steps are:

(1) First, stop the excavator, put the stick at the bottom, lower the boom, and flatten the bucket to the ground.

(2) Put the wire rope on the boom, and the short wire rope on the upper end of the boom cylinder, hook the two wire ropes with the iron hooks at both ends of the chain hoist, and then tighten the iron chain.

(3) Pull out the pin on the head of the piston rod of the boom cylinder, remove the oil inlet and outlet pipes, and place the boom cylinder on the platform.

(4) Remove the circlip and the key on the boom cylinder, put a rubber strip in the groove, and put it on the stick arm that is level with the boom cylinder and the piston rod pin hole of the boom cylinder. The steel wire ropes are connected to the chain hoist respectively, and then the iron chain is tightened to pull the piston rod out.

 (5)Replace the oil seal, and then install it in the reverse order of disassembly.