Product Description
RETAINING RING
Frequently Asked Questions
Q: What does the 00591-04397-81 retaining ring hold in place on a manual pallet jack?
A: The 00591-04397-81 is a snap ring or circlip used to retain pump shafts, bearing races, or piston rods within hydraulic cylinders and pump housings. It prevents axial movement under pressure cycles. This is a precision component, and the correct diameter, thickness, and groove fit are critical for safe operation.
Q: Which manual pallet jack models require the 00591-04397-81 retaining ring?
A: This retaining ring fits Crown, Toyota, Raymond, and similar manual pallet jack hydraulic systems. Verify your jack model, pump type, and cylinder bore diameter against the parts manual. Do not assume the ring fits all models from the same brand, as hydraulic bore sizes and groove dimensions vary by production year and pump configuration.
Q: How do I remove and install the 00591-04397-81 snap ring without damaging it?
A: Use only snap ring pliers with the correct jaw profile (internal or external) designed for this ring size. Do not use screwdrivers or hammers, which will bend or break the ring. When removing, spread the ring gently and support the shaft. When installing, seat the ring fully in its groove and verify it cannot rotate. Improper installation allows the component to shift and cause sudden loss of pressure.
Q: What material is the 00591-04397-81 retaining ring made from?
A: The retaining ring is made from spring steel, tempered and hardened to withstand repeated compression cycles under hydraulic pressure. Do not substitute with annealed steel or generic fastener rings, as they will lose tension and allow component movement. A compromised ring leads to seal damage, internal leakage, and equipment failure.
Q: Can I reuse the old 00591-04397-81 ring after removing it?
A: Do not reuse the old snap ring. Removal work-hardens or bends the metal, reducing its spring tension and grip. A reused ring will not hold the component securely and will result in axial drift, seal misalignment, and pressure loss. Always install a fresh ring from the 00591-04397-81 part number when reassembling hydraulic components.