Once high pressures are adjusted within specification, check the low pressures as follows: test the right brake pressure with the pedal pushed all the way in and no lever input, test the left brake pressure with the pedal pushed all the way in and no lever input, and test the brake pressures with the levers pulled all the way back and no pedal input. The brake pressures should be at 0 psi with the pedal depressed and at low pressure with only the levers pulled all the way back. If results show low pressures are not within specification, it may be necessary to readjust high pressures, adjust the brake transition pressures or look for internal mechanical leakage or failure.