00591-27378-81

Frequently Asked Questions

Q: What seals and components are included in the 00591-27378-81 kit?
A: The 00591-27378-81 is a Toyota OEM hydraulic polyurethane seal kit engineered for Toyota HPT25 manual pallet jack pump assemblies. The kit includes polyurethane (PU) seals sized for 18-millimeter pump pistons and 35-millimeter plunger applications. These seals maintain hydraulic fluid pressure and prevent internal leakage in the pump and pressure relief systems.

Q: Is this seal kit compatible only with HPT25 models, or other Toyota manual pallet jacks?
A: The 00591-27378-81 is specifically engineered for Toyota HPT25 manual pallet jack models. Do not use this kit on other Toyota models or non-Toyota equipment without confirming thread compatibility and port dimensions. Cross-referencing your equipment serial number or consulting the OEM parts manual ensures you order the correct seal kit for your specific manual pallet jack model.

Q: What is the lifespan of polyurethane seals, and when should they be replaced?
A: Polyurethane seals typically last 2 to 3 years under normal warehouse service, or 3 to 5 years in light-duty environments. Replace the 00591-27378-81 seal kit if you observe hydraulic fluid leaking from pump ports, sluggish lifting action, or inability to maintain pressure under load. Age-related seal degradation is common in equipment over 5 years old. Preventive replacement extends equipment reliability.

Q: What is the installation procedure for this seal kit?
A: Disassemble the HPT25 pump assembly by removing fasteners and separating the pump housing from the cylinder and plunger. Remove worn seals from the 18-millimeter pump piston and 35-millimeter plunger grooves. Clean all surfaces with a lint-free cloth and hydraulic solvent. Install new polyurethane seals from the kit, ensuring they sit evenly in the grooves without twisting or stretching. Reassemble the pump, torque fasteners to specification, and test for leaks before returning the pallet jack to service.

Q: What maintenance prevents seal failure and extends kit lifespan?
A: Use only the correct ISO-grade hydraulic fluid specified for the HPT25. Change fluid every 1 to 2 years or when discolored or contaminated. Keep the pump intake filter clean and check it monthly. Avoid exposing the pallet jack to extreme heat or direct sunlight for extended periods. Inspect hydraulic hoses quarterly for cracks or swelling and replace if compromised. Store the jack indoors in a dry location when not in use.

Q: Can I reuse the old seals, or must I purchase a complete new kit?
A: You must purchase the complete 00591-27378-81 kit. Individual seals are not sold separately, and reusing old polyurethane seals compromises hydraulic integrity and creates leak risk. Once removed, worn seals cannot be reliably reinstalled. Always install fresh seals from a new kit to ensure factory performance and warranty compliance.