Control measuring axial hub runout, front wheels

Raise the car and remove the front wheels.
Begin by performing a control measurement on one side.
Press in the piston by prying with a screwdriver against the brake pads.

Fig 1: Illustration For Steps 3-4
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Remove the brake caliper retaining bolts and lift off the caliper.
NOTE: Inspect the wheel sensor cable for damage.
Suspend the caliper with straps.

Fig 2: Identifying Brake Caliper And Brake Disc Locking Bolt
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Remove the brake disc locking bolt.
Lift off the brake disc.
Fit 89 96 639 GAUGE, BRAKE DISC on the upper mounting lug of the brake calliper with an M10 nut and bolt. Fit a 83 90 288 HOLDER, DIAL GAUGE and 78 40 622 DIAL INDICATOR .

Fig 3: Checking Runout Using Dial Gauge
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Rotate the hub and check the runout (the value between the highest and lowest reading).
If the runout exceeds 0.03 mm, replace the hub.

NOTE: The dial gauge should read 0.03-0.05 mm at each bolt hole. This is completely normal.
Remove the dial gauge and bracket.
If the measured runout values are outside the tolerances, replace the hub, see WHEEL HUB, FRONT .
Clean the contact surfaces between the hub and the brake disc.
Place the brake disc on the hub and fit the brake disc locking bolt.
Tightening torque 7 Nm (5 lbf ft)

Fig 4: Identifying Brake Disc Locking Bolt
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Fit the brake caliper, lock the bolt threads with 74 96 268 Thread locking adhesive.
Tightening torque 210 Nm +30° (155 lbf ft +30°)

Fig 5: Identifying Brake Caliper Bolts
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Fit the wheel.
Repeat the measurement method for the other front wheel.
Lower the car and press the brake pedal in order to press out the brake pads.