Honda Accord 2004 - Brake problem

[carboy2017]

I drive a 2004 Accord i-vtec and currently on 116k on the clock,I have been noticing that the braking is not efficinet as how it should be and today it nearly failed in an emergency stop on a gravel country lane

When I applied the brakes it took time to stop and I could also hear a slight grating noise and the pedal also seems to go in a bit,gradual braking seems ok

to give a bit of history I had the brake fluid flushed and replaced in November and also have changed all 4 pads (front in Nov and rear in April),I asked the garage to check on discs and they said its fine

any ideas as to what can the issue be? recently my friends 05 Golfs brakes failed and the fault was a servo hose as per RAC guy who came,could it be something similar?

any help/suggestions appriciated