Check fitment before ordering
This is a WSS aftermarket replacement for FOX reference 036-01-018. It fits selected legacy FOX 32 FLOAT, F29 and TALAS II air-spring assemblies—not every FOX 32, F100 or F120 fork.
Brand
WSS
WSS part number
RSSP1218
Replaces FOX reference
036-01-018
Package contents
1 air-piston U-cup
What this seal does
The RSSP1218 U-cup seals the positive air piston against the inside of the upper tube in selected older FOX 32 air springs. FOX also used 036-01-018 on the lower outer piston of certain 32 TALAS II systems. It is an internal pressure seal—not a dust wiper and not the separate scraper seal found on some later air pistons.
Quick fitment guide
FOX document confirmed
- 2005–2006 FOX 32 FLOAT 130, including documented R, RL, RLC and X/Trail Tune versions
- 2007 FOX 32 FLOAT 140 and documented 2007 32 TALAS II lower-piston applications
- 2008 FOX 32 F120/FLOAT 120, FLOAT 130 and FLOAT 140 using the documented air shafts
- 2008–2009 F29/29er 80, 100 and 120
- Selected 2011-origin F29 legacy air shafts, including 80, 90, 100 and the documented 120 shaft family
- Special 2013–2014 29-inch 110 mm fork built on the older 80–100 mm chassis
- 2014–2015 Factory/Performance F29 80, 90 and 100
Variant-dependent—verify first
- Late-2010 through 2013 OEM FLOAT and F29 applications
- 2012 80–120 mm forks where Kashima generation and piston architecture differ
- OEM-specific travel such as 125 or 130 mm
- Any fork identified only as “FOX 32,” “F100” or “F120”
Known non-fitments
- Many conventional F80/F100 and early FLOAT 80/100 forks, which use 036-01-010 or 036-01-011
- Conventional 2008 32 mm 80/90/100 air shafts
- 2014 Evolution 29-inch 80–100
- Standard/new 2014 29-inch 110/120/130
- 2015 Evolution 29-inch 80–100 and standard 2015 29-inch 110–130
- 2016 and newer FLOAT NA2
- FOX 34, 36, 40 forks and FLOAT rear shocks
Check the complete FOX 036-01-018 fitment guide
How to verify your fork
- Check the removed U-cup for 036-01-018 molded or stamped on its bottom surface.
- Record the fork’s model year, wheel size, travel and series: Factory, Performance or Evolution.
- Check the FOX product code/serial number and, when available, the air-shaft assembly number.
- If you are still unsure, contact us with the fork information and clear photographs before ordering.
Dimensions
- WSS RSSP1218 nominal size: approximately 21.61 × 27.81 × 3.78 mm
- Original FOX/NOK seal marking reported from physical seals: approximately 21.41 × 27.81 × 3.8 mm
FOX dimensional specifications were not found in the surviving primary manuals. The small ID difference reflects the published WSS nominal specification versus markings recorded from original FOX/NOK seals; use the part-number and air-spring application as the primary verification.
Installation note
FOX’s legacy instructions orient the U-cup’s sealing lip or triangular outside sealing edge toward the top of the piston and the positive air chamber. Completely release air pressure before disassembly, use the correct service procedure for the exact fork, and inspect the upper-tube sealing surface. This page is fitment guidance, not a substitute for the complete FOX service manual.
What is included
Included: one new WSS RSSP1218 air-piston U-cup seal.
Not included: dust wipers, scraper U-cup, O-rings, crush washers, FLOAT fluid, bath oil, tools or a complete rebuild kit unless they are shown and named as part of a separate bundle.
Why Full Suspension documents legacy fitment
Older suspension should remain serviceable. We compare FOX manuals, engineering drawings and real-world service evidence so riders can identify the correct part instead of guessing from travel or model name alone.
