The tester can be used as a digital brake fluid tester suitable for determining brake fluid quality. Developed for professional use in astomotive repair shops and in servicing. Quality is tested and included on five LEDs in terms of "per cent of water in the brake fluid . "
Ready for Brake Fluid Test
Unscrew the brake fluid reservoir, and pull off the cap of the Brake fluid tester.Dip the test probes into the brake fluid up to the plastic rim of the device.
To check Fluid Quality
Press the button for power on, green LED will light up. Insert the tester into reservoir for one second then the tester result will be correctly indicated by LEDs.Repress the button for power off. The tester will automatically power off after about 15 seconds of inactivity.
Tester Specification:
1. To check the quality of brake fluid quality
2. 5 LEDs to indicate percentage of water in the brake fluid
3. Automatically power off
4. Operated by a LR03 AAA 1.5V battery (Not included)
Tester Instructions:
Brake fluid detection pen is based on the change in conductivity to determine the moisture change brake fluid. It shows clearly the extent of moisture contained by the light-emitting diode, high moisture content will lead to lower boiling point, affect braking performance. Red indicates the brake fluid needs immediate replacement, green represents good condition, yellow indicates the state is acceptable but soon replaced.
1. the green LED lights = water content in the brake fluid H2O <1.5%, brake fluid qualified
2. the yellow LED lights = brake fluid water content H2O = 1.5% to 3%, can continue to use, test again six months later
3. the red LED lights = water content in the brake fluid H2O> 3%, can not continue to use the brake fluid needs to be replaced Red LED: change brake fluid 
Tester Features:
Five LED indicators show