While you’re at it, replace the front and rear master cup pistons too.
The inlet area is rough too, so let’s polish it.
Here we cleaned up the rear brake master (already polished).
Since it opens when hydraulic pressure is applied, leaks are usually minimal. When wear develops, there’s lag before it opens, which might make the feel softer.
When there’s no manual, comparing old and new parts gives you peace of mind.
