[greg bradbury]

hi,

To test the booster do this- With the engine off apply the brakes two or three times. this will deplete the stored vacuum in the booster. The pedal should become hard to push. Hold the pedal down and start the engine, The pedal will go down slightly as the booster helps out. If the booster was faulty then your braking would be terrible (scary)/

Have you rebuilt the calipers lately? If so you might try putting the old pads back in and drive it around like that for a few 100 miles to let the calipers come out. Once the sponginess goes push the calipers back just enough for the new pads the go in.