Product Description
The LL-550-6-21 is a direct replacement U-Cup hydraulic seal for Lo-Lift manual pallet jacks. This critical maintenance component prevents hydraulic fluid leakage in the lift cylinder, maintaining system pressure and lifting performance. Designed for original equipment compatibility with Lo-Lift-manufactured pallet jacks. No cross-reference alternatives were identified in approved parts catalogs.
Specifications
Part Numbers
| OEM Part Number | LL-550-6-21 |
| Alternate Part Number | LOLL-550-6-21 |
Frequently Asked Questions
Q: What is the LL LL-550-6-21 U-Cup seal?
A: The LL LL-550-6-21 is a U-Cup hydraulic seal component for Lo-Lift manual pallet jacks. U-Cup seals are specifically designed for bidirectional movement in hydraulic cylinders and provide superior leak prevention compared to simple O-rings.
Q: What equipment is this seal compatible with?
A: This seal is designed for Lo-Lift-manufactured pallet jacks. Verify your equipment documentation shows Lo-Lift origin and matches the part number designation before ordering.
Q: Where does the U-Cup seal install in the lift mechanism?
A: U-Cup seals are typically installed in the main hydraulic cylinder bore to seal the rod and prevent hydraulic fluid loss during lift and lower cycles. This seal is critical for maintaining pressure and system performance.
Q: What are signs this U-Cup seal is failing?
A: Failure indicators include hydraulic fluid seeping from the cylinder base or rod, inability to hold load height, slow or incomplete lifting, or oil spots under the jack after parking. Any of these symptoms require immediate seal replacement.
Q: What is the alternate part number for this seal?
A: The alternate part number is LOLL-550-6-21. Both designations reference the same component. Use LL LL-550-6-21 as the primary ordering number.
Q: How long does a U-Cup seal typically last?
A: U-Cup seal lifespan varies with equipment usage frequency and maintenance. Inspect regularly for leaks. Replace immediately if hydraulic loss is observed, as continued operation without a proper seal damages the cylinder bore.