Work Procedure

When installing a brake booster (996 355 923 00) with new bellows and seal in a vehicle produced before the introduction date specified the vehicle must be converted to the new seal. The procedure is outlined in (soon to be released) supplement 61 for the 911 Carrera (996) Technical Manual, in Group 47 70 31.

The corresponding chapter from the Technical Manual (included in supplement 61) is shown with this Technical Information. Please use that for the bases of the repair.

The following procedure is a short overview of the work to be carried out. Use the work procedure from supplement 61 to perform the repairs.

1. Position vehicle on lifting platform and raise.

2. Remove all wheels (after conversion, the brakes must be completely bled).

3. Remove battery.

4. Remove brake booster (Fig. 1 item 4) with brake master cylinder. To do so, the hydraulic unit, and in the case of vehicles with PSM, the booster pump must also be removed.

5. Remove bellows and rubber grommet (Fig. 1 item 1, 2, 3), brake push rod (Fig. 1 item 9) and intermediate piece (Fig. 1 item 11).

6. If necessary, completely remove the sealing ring at the opening in the body firewall.

7. Insert the sealing ring (Fig.1 item 7.2) without lubricant in the opening in the body firewall.

8. Insert the connecting piece (Fig. 1 item 7.1) with rubber lubricant into the sealing ring (Fig. 1 item 7.2).

9. Mount the sealing ring (Fig. 1 item 7.3) onto the connecting piece (Fig. 1 item 7.1).

10. Install the intermediate piece (Fig. 1 item 11).

11. Install a new brake push rod (Fig. 1 item 9.1), using a new pin and a new threaded bushing. The brake push rod must be replaced because the double rib (Fig. 1 item 9, arrow) for the grommet uptake on the previous brake push rod brushes against the new seal.

12. Mount the new push rod (Fig. 1 item 12.1) with hexagon nut M6 (Fig. 1 item 13.1) on the brake booster (Fig. 1 item 4). It is only necessary to replace the push rod (Fig. 1 item 12) when the tab washer (Fig. 1 item 13) is installed. Set the push rod on the brake booster to the basic setting.

13. Install brake booster (Fig. 1 item 4) and brake master cylinder with mounted bellows (Fig. 1 item B) and tightly fastened clamp (Fig. 1 item 6).

14. Connect the brake push rod (Fig. 1 item 9.1) and the push rod (Fig. 1 item 12.1). To do so, mount the hexagon nut (Fig. 1 item 13.1). Overview of work to be carried out (ctd.; Fig. 1 item nos.):

15. Check or adjust the position of the brake pedal. Check the stop light switch setting.

16. Position the bellows (Fig. 1 item B) on the connection sleeve (Fig. 1 item 7.1) and secure with the hose clamp (Fig. 1 item 6.1).

17. Install hydraulic unit and booster pump (in vehicles with PSM).

18. Install battery.

19. Bleed brake, ensure that the vehicle is correctly re-equipped, and perform the necessary tests (see 911 Carrera (996) Technical Manual or details in the enclosure to this TI, Group 47 70 31, Supplement 61.

20. Perform the work made necessary by disconnection of the battery (Technical Manual = Repair group 9: Work instruction after disconnecting the battery).

21. Remove vehicle from the lifting platform.

22. Perform function test on brakes before leaving the lift vehicle hoist area.