Toyota Celica/Supra 1971-1985 Repair Guide

Brake Disc (Rotor)

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REMOVAL & INSTALLATION



  1. Remove the brake pads and the caliper, as previously detailed.
  2.  
  3. Check the disc run-out, as detailed following, at this point. Make a note of the results for use during installation.
  4.  
  5. Remove the grease cap from the hub. Remove the cotter pin and the castellated nut.
  6.  
  7. Remove the wheel hub with the brake disc attached.
  8.  
  9. Perform the disc inspection procedure, as outlined in the following information.
  10.  

To install:
  1. Coat the hub oil seal lip with multi-purpose grease and install the disc/hub assembly.
  2.  
  3. Adjust the wheel bearing preload, as detailed following.
  4.  
  5. Measure the disc run-out. Check it against the specifications in the Brake Specifications chart and against the figures noted during removal.
  6.  

If the wheel bearing nut is improperly tightened, disc run-out will be affected.

  1. Install the remainder of the components as outlined in the appropriate preceding information.
  2.  
  3. Bleed the brake system.
  4.  
  5. Road test the car. Check the wheel bearing preload.
  6.  

INSPECTION



Examine the disc. If it is worn, warped or scored, it must be replaced. Check the thickness of the disc against the specifications given in the Brake Specifications chart. If it is below specifications, replace it. Use a micrometer to measure the thickness.

The disc run-out should be measured before the disc is removed and again, after the disc is installed. Use a dial indicator mounted on a stand, and position the pointer 0.39 inch (10mm) from the edge of the disc. If run-out exceeds 0.006 inch (0.15mm), replace the disc.

Be sure that the wheel bearing nut is properly tightened. If it is not, an inaccurate run-out reading may be obtained. If different run-out readings are obtained with the same disc, between removal and installation, this is probably the cause. For Wheel Bearing removal, installation and adjustment, please refer to Suspension & Steering (under Front Axle Hub and Bearing).

PRELOAD ADJUSTMENT



See Figures 1 and 2

  1. With the front hub/disc assembly installed, tighten the castellated nut to the torque figure specified in the Preload Specifications chart.
  2.  
  3. Rotate the disc back and forth, two or three times, to allow the bearing to seat properly.
  4.  
  5. Loosen the castellated nut until it is only finger-tight.
  6.  
  7. Tighten the nut firmly, using a box wrench. Make sure the disc rotates smoothly.
  8.  
  9. Measure the bearing preload with a spring scale attached to a wheel mounting stud. Check it against the specifications given in the Preload Specifications chart.
  10.  
  11. Install the cotter pin.
  12.  

If the hole does not align with the nut (or cap) holes, tighten the nut slightly until it does.

  1. Finish installing the brake components and the wheel.
  2.  



Click image to see an enlarged view

Fig. Fig. 1: Preload specification chart



Click image to see an enlarged view

Fig. Fig. 2: Tighten the nut firmly, then measure the preload with a spring scale

 
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