Depressing brake calipers?

[Hillbilly]

Crack open the bleed valve, this will allow expansion of the dirty brake fluid. Use a bleed kit, as you will need to bleed the brakes after.
If you just release the pressure by loosen the cap, old fluid will drain back into the line possibly causing problem in future.

Why do that and potentially create another problem of air in the line when a simple G cramp will push it back without other problems.

Have used that method for 40 years without trouble.

Never crack a line unless you absolutely have to.

[RolfGolf]

Never crack a line unless you absolutely have to.

I agree - stay clear of drugs like Hillbilly says!