Hmmm, I must have a different type as the cap on mine domes outwards (unless that is your custom cap). Nonetheless, as Paul G mentioned, it might be a better idea to just get it rebuilt by GT. Andy - Would you be able to PM me a quote for a rebuild with a schrader valve end cap (Rider weight 70kg)?

I have no idea why Honda made these shocks so hard to service! They're supposed to be performance motorcycles!