Overview of bellows conversion

• To convert the bellows variant -A-  to version -A1-  , the hydraulic unit, the brake booster -4-  with brake master cylinder and the intermediate piece -11-  must be removed. Refer to Fig 1 .
• The assembly of the brake master cylinder with the brake booster -4-  must not be disconnected for removal and installation if both parts should be continued to be used! Refer to Fig 1 .
• To remove the intermediate piece -11-  , the battery must be removed! This will prevent damage of the components in the surrounding area. Refer to Fig 1 .
• The following parts must be exchanged or replaced for first installation of variant -A1-  (replacement ausfuhrung):
  • Remove short bellows -2- on the brake booster and the long bellows -1- on the firewall.
  • Remove the grommet (rubber groove ring) -3-  for mounting the long (former) bellows (not replaced). Refer to Fig 1 .
  • The following parts are used in place of the removed parts -1 / 2 / 3-  : Bellows -B-  (already mounted on new brake boosters), connection sleeve -7.1-  with sealing ring -7.3-  , the seal for the firewall -7.2-  and the hose clamps (clamps) -6 and 6.1-. 
  • The two push rods -12 and 9-  are to be replaced with the modified version -12.1 and 9.1-  . Refer to Fig 1 .

Difference in the push rods:

1. Push rods -12.1-  with thread and fastening nut -13.1-  in place of push rod -12-  with retainer -13-.  Refer to Fig 1 .
2. A guide for the bellows -arrow-  is present in the previous push rod -9-  . Refer to Fig 1 . A guide is not present and not permissible in the new push rod -9.1-  !

Fig 1: Identifying Bellows Components

Courtesy of PORSCHE OF NORTH AMERICA, INC.