U-CUP

810 787 69 SEAL, U Installed deep inside a hydraulic drifter or rotation motor, this U-CUP seal works on a piston to prevent internal fluid leakage. It ensures that the high-pressure hydraulic oil effectively drives the piston, generating the powerful impact energy or rotation torque needed for efficient drilling. Without a proper seal, hydraulic pressure is lost, and the machine's performance drops significantly.

A worn or damaged U-CUP seal is a common cause of reduced drilling penetration. When it fails to hold pressure, the drifter's hammer loses its force, slowing down the entire operation. This internal leakage also generates excess heat in the hydraulic system, which can degrade the oil and lead to premature wear on other expensive components, increasing the risk of unexpected downtime.

If you notice a gradual loss of impact power or weak rotation, and the system's pressures seem correct, an internal seal like this may be the cause. These seals are wear parts and should be replaced during any major drifter or motor overhaul. For best results, always use the complete seal kit for the job to ensure long-lasting reliability after a rebuild.