Wilden T15 Spare Parts Guide: 8 Common Replacement Parts

Most T15 rebuilds don’t involve just one part. A worn shaft chews up a shaft seal, a bad center block defeats a brand-new gasket, and a diaphragm swap is usually the moment someone finally checks the valve seat too. The eight parts below cover the T15’s air end and wet end, roughly in the order a thorough rebuild would touch them.

• Air Valve (15-2000-07) — brass, position 1 on the parts list, switches compressed air between the two chambers on every stroke.
• Center Block (15-3100-01-225) — the aluminum housing the air valve, shaft and both chambers bolt onto.
• Shaft (15-3800-09-07) — connects the two diaphragms through the center block; its surface condition decides how long seals last.
• Glyd Ring / Shaft Seal (15-3210-55-225) — PTFE seal around the shaft where it passes through the center block.
• Center Block Gasket (15-3520-52) — Buna-N gasket sealing the center block joint.
• Diaphragm (15-1010-51) — neoprene, the part that actually flexes to move fluid.
• Valve Seat (15-1120-51) — neoprene, the landing surface each check ball seals against.
• Washer (15-6850-08) — mild steel inner piston back-up washer, position 18.

Each part below links to the next one in this sequence, so if you’re tracing a fault from one component to another, you can follow the chain rather than searching for each part separately.