MU 0745905

Frequently Asked Questions

Q: What is a back-up ring and what does it do in a hydraulic system?
A: A back-up ring is a support component that prevents elastomer seals from extruding into gaps between mating surfaces under high hydraulic pressure. The MU 0745905 back-up ring provides static or dynamic anti-extrusion sealing in pump or cylinder assemblies, extending seal life and maintaining system integrity.

Q: What manual pallet jack models require the MU 0745905 back-up ring?
A: The MU 0745905 is a genuine OEM back-up ring for Multiton manual pallet jack models. This component is used in hydraulic pump and cylinder assemblies. Verify your equipment model and seal kit part number to confirm compatibility before ordering.

Q: When does a back-up ring require replacement?
A: Replace the back-up ring whenever you replace primary seals in the pump or cylinder, as the ring material hardens over time and loses anti-extrusion capability. Also replace if the ring is visibly cracked, scored, or deformed during seal inspection.

Q: What happens if a back-up ring is not replaced with new seals?
A: A worn back-up ring cannot prevent new seal extrusion under pressure, causing premature failure of replacement seals. This leads to renewed hydraulic leakage shortly after seal service. Always replace back-up rings as part of a complete seal kit replacement.

Q: What material is this back-up ring made from?
A: Genuine Multiton back-up rings are manufactured from rigid polymer or composite material formulated to resist extrusion, compression set, and chemical degradation from prolonged exposure to hydraulic fluids at elevated pressures and temperatures.