Reduced Braking Power

[RusT]

Hi Everyone, 

I need your help in diagnosing a brake issue in my car. Since last Thursday or so, the braking power in my car has been reduced and I need to press the pedal more than I used to to get the brakes work fully. 

I also saw similar threads posted by the members some time ago such as:

My car is a Vitz (SCP90) and the recently following repairs were done to the braking system:
- Bleed and replace brake fluid (Around 6 months ago).

- Replaced both front pads and rear shoes (Akebono, around 4 months ago) and drums were also resurfaced.

Observed the following as well:

- No any warning lights on the dash.

- Reduced brake power is consistent, however if the pedal is pumped twice, the brakes will grab as it used to earlier.

- No reduction in brake fluid.

All the repairs mentioned above were done at the same garage that I usually do my repairs and when I took the car to them yesterday they told that it could be an issue with the master cylinder. They said they'll have to inspect further before confirming the exact issue (will be taking in the car tomorrow).

I want to know what to look out for, as if it is the master cylinder, can it be rebuilt using a washer kit or does it have to be replaced?

Any other areas I need to check for any leaks or other signs.


Really appreciate your thoughts on this.