Product Description
Manual pallet jack hydraulic seal kit, SKU GW 518, engineered for aftermarket replacement and OEM-grade repair of pallet jack pump assemblies. Compatible with hydraulic systems up to 3000 PSI, includes NBR, FKM, and PU sealing elements for shafts and bores ranging from 9 mm to 32 mm. GW 518 supersedes equivalent aftermarket references GP518 and GW518. Suitable for routine hydraulic pump restoration in manual pallet trucks.
Specifications
Hydraulic
| Pressure Rating | Compatible with hydraulic systems rated up to 3000 PSI |
Material & Construction
| Back-up Ring Material | Nylon and PTFE per component type |
| Wiper/Dust Seal Material | Phenolic fabric or polyurethane (PU), per manufacturer design |
Part Numbers
| Cross-Reference Part Numbers | Equivalent to GW518, GP 518, GP518 |
| OEM Part Number | GW 518 |
| Manufacturer Part Number | GW 518 |
| No cross-reference part numbers available | No manufacturer cross-supersession or OEM replacement numbers are published beyond GW518 / GP518 |
Frequently Asked Questions
Q: Are GW 518 and GP 518 interchangeable?
A: Yes. GW 518 is the current OEM-equivalent replacement for GP 518 and GP518 part numbers. All three are identical in seal geometry and performance. Use GW 518 for new orders and replacements; older references GP518 and GP 518 are deprecated.
Q: What bore and shaft sizes does GW 518 cover?
A: GW 518 is engineered for hydraulic pump shafts and bores ranging from 9 mm to 32 mm diameter. The kit contains a range of seal sizes (rod seals, piston seals, O-rings) to fit these common pump configurations. Verify your pump bore diameter before ordering—seals for a 12 mm bore will not fit a 20 mm bore.
Q: What seal materials are in GW 518?
A: GW 518 combines three elastomer types: NBR nitrile rubber (standard hydraulic seals), FKM fluoroelastomer (high-temperature and chemical resistance), and polyurethane (PU) rod seals. Nylon and PTFE backup rings prevent extrusion under pressure. Material selection depends on the specific seal position and pump design.
Q: How do I diagnose if GW 518 seals are failing?
A: Watch for slow lift, weak pump pressure, oil weeping around the pump rod or bore, or hard pump handle resistance. To confirm, inspect the pump visually for oil residue on external surfaces and check hydraulic fluid color and odor (burnt smell indicates seal friction and overheating). Drain and examine the oil for metal particles, which indicate seal material degradation.
Q: What is the pressure rating and service life of GW 518?
A: GW 518 is rated for 3000 PSI maximum operating pressure. Under typical warehouse use, seals last 2 to 5 years depending on fluid cleanliness, temperature, and pump duty cycle. Contaminated hydraulic fluid significantly shortens lifespan; always use clean, manufacturer-approved hydraulic oil and replace filters regularly.
