Service Brake

Check the free play of brake pedal with a force of less than 10 N (1 kgf, 2 lb).
Brake pedal free play:

0.5 - 2.0 mm (0.02 - 0.08 in)

Fig 1: Identifying Free Play Of Brake Pedal
Courtesy of SUBARU OF AMERICA, INC.
If the free play is out of the specifications values, adjust the brake pedal as follows.
1. Make sure the engine is off. (No vacuum is applied to brake booster.)
2. Inspect that there is play between brake booster clevis and pin at brake pedal installing portion.
  [Depress brake pedal pad with a force of less than 10 N (1 kgf, 2 lb) to a stroke of 0.5 to 2.0 mm (0.02 to 0.08 in).]
3. Depress the surface of brake pad by hand.
4. If there is no free play between clevis pin and clevis, turn brake switch adjusting nut until the clearance between stopper and screw of brake switch becomes 0.3 mm (0.012 in).
  
  Fig 2: Identifying Brake Switch, Adjusting Nut, Stopper, Clevis Pin And Lock Nut
  Courtesy of SUBARU OF AMERICA, INC.
Check the pedal stroke.
While the engine is idling, depress the brake pedal with a 490 N (50 kgf, 110 lb) load and measure the distance between the brake pedal and steering wheel. With the brake pedal released, measure the distance between pedal and steering wheel again. The difference between the two measured values must be less than specified value. If the measured value is more than specification, there is possibility of entering air in hydraulic unit.

Brake pedal stroke A

105 mm (4.13 in) or less/490 N (50 kgf, 110 lb)

Fig 3: Identifying Steering Wheel And Toe Board
Courtesy of SUBARU OF AMERICA, INC.
Check to see if air is in the hydraulic brake line by the feel of pedal operation. If air appears to exist in the line, bleed it from the system.
Check for even operation of all brakes, using a brake tester or by driving the vehicle for a short distance on a straight road.