NG 900/9-3 Rear Rotors

From The Saab Tech Wiki
Jump to: navigation, search

Overview

Rotors can be inspected with the wheel off, but can only be removed after the caliper has been detached and moved out of the way. If the pads are being replaced at the same time, they should be removed first and installed last. Besides rotors, new set screws may be required because they are often rusted and the torx head can be damaged or stripped during removal.

Fig. 1 - Rear Brake
Fig. 2 - Rear Rotor Diagram

Dissassembly

Brake Line

The brake line runs along the back plate in the same area as the handrake cable and the wheel sensor electrical cable.

First loosen but do not disconnect the 10-mm brake line union nut. Use penetrating oil and a flare nut wrench to avoid damage. The brake line should then be released from the white plastic retaining clip before the caliper bolts are taken out.

Fig. 3 - Rear Brake Line

Caliper Bolts

The 19-mm (3/4-inch) caliper bolts should be soaked in penetrating oil one or two days earlier, and again before disassembly. They can take some effort to break loose, and may require a longer handle than the typical 3/8-drive ratchet.

Fig. 4 - Rear Brake Caliper Bolts

Caliper

The caliper can be left connected to the brake line to avoid any brake fluid loss, and just swung out of the way. It has to be supported from the bottom as shown at left. In that case bleeding the brakes may not be necessary.

If the caliper is disconnected from the brake line and removed to inspect the caliper pistons and seals, some brake fluid will be lost, and bleeding the rear brakes will be required.

Fig. 5 - Rear Brake Caliper Set Aside

Rotor

With the hand brake released and caliper out of the way, the rotor is held by one T-30 torx set screw.

Remove the screw, if necessary with the help of more penetrating oil, and slide the rotor off the wheel hub. If the rotor does not come off easily, it may be necessary to back off the handbrake adjuster to give the brake shoes inside some extra room.

Fig. 6 - Rear Brake Set Screw and Hand Brake Adjuster Access

Reassembly

Reassemble in reverse order. Clean and apply anti-seize to the face of the hub, set screw, and face of the rotor being installed. Replace the set screws if rusted, or if the head was damaged during removal.

Adjust the hand brake shoes to allow the hub to spin freely with the hand brake released, and to grab on the 5th-6th click of the handbrake lever.

Fig. 7 - Rear Brake Reassembly

Hand Brake Adjuster

The adjuster can be backed off using a screwdriver or a similar tool to loosen the handbrake shoes and give the rotor room to slide off the wheel hub.

Access

Turn the rotor to position the access hole sligtly to the rear of 6 o'clock.. Insert a screwdriver or a similar tool into the access hole, and rotate the star-shaped wheel one tooth at a time. There is some resistance as the teeth slide past a spring inside the rotor.

Fig. 8 - Hand Brake Adjustment

Adjustment

To back off the adjuster, turn the wheel down on the left, and up on the right rear hub.

To tighten the adjuster, turn the wheel up on the left rear wheel, down on the right.

Fig. 9 - Hand Brake Adjuster

Information

Rotor Thickness

10 mm (new)

8 mm (minimum)

References

Saab EPC 5-0150

Haynes Ch 9, section 9

Torque Settings

Caliper bolts, 59 lb-ft

Set screw, 7 lb-ft

Tools Used

  • 3/8-drive ratchet
  • 19-mm socket
  • 10-mm flare nut wrench
  • T-30 torx bit
  • Torque wrench
  • Wire brush
  • PB Blaster
  • Brake cleaner
  • Anti-seize