Having problems bleeding my Saint M820 brakes.
Should I be bleeding with the free stroke adjuster screw backed off?
also if you look at the master cylinder at the lever end, it has a gold cap with threaded hole in it, what is the purpose of this?

Cheers 😕

Yes bleed with the free stroke backed off.

The gold piece is the pressure relief valve. As the fluid expands and contracts air will pass through the hole and you may see a little fluid there if the system becomes overfilled at any point.

Ok then can the relief valve become faulty and pass air into the system?
Only reason I ask is I can bleed them and all is sweet, then a dozen rides they become spongey.