Hunter 181500 PGP Riser Seal — Replacement for 253400

Replacement riser seal designed for Hunter PGP series rotors. Part 181500 (SKU 181500SP) is sold individually to stop water leaking around the riser stem and restore reliable retraction and sealing on PGP, PGP Ultra and I‑20 (12") rotors.

• Direct replacement for the PGP riser seal — use when a single worn seal needs replacement.
• Compatible with Hunter PGP, PGP Ultra and I‑20‑12 rotors; replaces the 10‑piece kit (253400) when only one seal is required.
• Flexible rubber construction provides a pressure‑activated wiping seal that reduces leaks and improves retraction.
• Easy to install with basic disassembly: remove body cap and internal assembly, take off the old seal, fit the spring seat, then slide the new seal into place.
• Sold as a single seal (SKU 181500SP); spring seat is usually not needed for most repairs per service guidance.

Follow Hunter's installation guidance and verify final installation height and seating before pressurizing the system to ensure leak‑free performance. If you prefer a multi‑pack or kit that includes spring seats, see part 253400 (ten seals and spring seats). For detailed steps and troubleshooting, refer to Hunter's rotor support and the "Replacing a Riser Seal on a Rotor" video.