Hi!
I own a Specialized Stumpjumper FSR XC Pro, equipped with a Rockshox SID Hydrair XC Suspension Fork. These days, I noticed that it loses air quite fast, bottoming out only in a few hours after having been pumped. I asked a local bike shop for an opinion about why that happens, and the guy there told me that the valve is not suited to the fork, but improvised. He also told me that a suited valve for this type of fork is hard to find and that, if I wanted to fix the problem, I should buy another fork, given the fact that valves for this type are really hard to find.

I sought the internet a bit, and I found some versions of valves, but I'm not sure whether they're what I'm looking for or not. Some examples are of products from amazon, sram or chainreactioncycles, but unfortunately I cannot post the link to them. I will try to add a comment containing the links.

So, I thought of asking you guys for help. Do you happen to know what I need? Can I actually replace the valve, or do I have to entirely change the fork? Are the links even close to what I'm looking for? If not, what else am I looking for?

I'll also attach a picture of the actual fork and of the valve.

Thank you!!