I have a Hitachi NR90AC5 framing nailer that still functions correctly, but some air leaks from around the trigger. Sometimes, after firing a few nails, it doesn't leak air anymore. Then later after more nails are fired, it goes back to leaking again. The performance of the gun is unaffected, but I'm concerned something may be wearing out.
It hasn't been used that heavily and I oil it every day.
What part needs replaced to make it stop occasionally leaking from the trigger?