Measuring Brake Drag Torque

1. Take out the drive shaft, if servicing a drive wheel. Refer to "Drive/Propeller Shaft." Set the special tool to the front hub assembly as shown in the illustration.





2. Measure hub torque (A) with pads removed to measure brake drag torque. The torque value will be used later to calculate brake drag force with the pads installed.

NOTE: Tighten the nuts in order to secure the disc to the hub.

3. Check brake drag torque as follows.
4. With the pads/caliper installed, start the engine and hold the brake pedal down for 5 seconds. Pedal depression force is approximately 196 N (44 lbs.)
5. Stop the engine and turn brake disc forward 10 times.
6. Check hub torque "B" with spring scale.
7. Calculate the drag torque of the disc brake (difference between hub torque "B" and hub torque "A"). The standard value is 69 N (15.4 lbs.) or less.
8. If the difference between brake drag torque and hub torque exceeds the standard value, disassemble piston and clean the piston. Check for corrosion or worn piston seal, and check the silding condition of the lock pin and guide pin.
9. Reinstall the drive shaft, if necessary. Refer to "Drive/Propeller Shaft."