Method-Using Tester

Connect the SST  , vacuum gauge (circle A), and pedal depression force gauge (circle B) as shown in the figure. After bleeding the air from the SST  , conduct the test as described in the 3 steps below.

Fig 1: Illustrating Pedal Depression Force Gauge

1. Checking for vacuum loss (Unloaded condition) 
   1. Start the engine.
   2. Stop the engine when the vacuum gauge reading reaches 66.7 kPa (500 mm Hg, 19.7 in. Hg). 
   3. Observe the vacuum gauge for 15 seconds. If the gauge shows 63.3~66.7 kPa (475~500 mm Hg, 18.7~19.7 in. Hg)  , the unit is operating.
      Fig 2: Testing For Vacuum Loss (Unloaded Condition)

      

   Loaded condition 

   1. Start the engine.
   2. Depress the brake pedal with a force of 196 N (20 kg, 44 lb). 
   3. With the brake pedal depressed, stop the engine when the vacuum gauge reading reaches 66.7 kPa (500 mm Hg, 19.7 in. Hg)  .
   4. Observe the vacuum gauge for 15 seconds. If the gauge shows 63.3~66.7 kPa (475~500 mm Hg, 18.7~19.7 in. Hg)  , the unit is operating.
      Fig 3: Testing Vacuum Loss (Loaded Condition)

      
2. Checking for hydraulic pressure
   1. If with the engine stopped (vacuum 0 kPa (0 mm Hg, 0 in. Hg)  ) the fluid pressure is within the specification, the unit is operating.
      ENGINE OFF FLUID PRESSURE CHART
      
      

      Pedal Force N (kg, lb)	Fluid Pressure kPa (kg/cm2 , psi)
      196 (20, 44)	1,177 (12, 171)

      Fig 4: Checking Hydraulic Pressure With Engine Stopped

      
   2. Start the engine. Depress the brake pedal when the vacuum reaches 66.7 kPa (500 mm Hg, 19.7 in. Hg)  . If the fluid pressure is within the specification, the unit will operate.
      ENGINE ON FLUID PRESSURE CHART
      
      

      Pedal Force N (kg, lb)	Fluid Pressure kPa (kg/cm2 , psi)
      196 (20, 44)	8,040 (82, 1,165)

      Fig 5: Checking Hydraulic Pressure With Engine Running