GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Yukon XL - 2WD 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Master Cylinder Adapter Replacement

Removal Procedure
  1. Place the ignition switch in the OFF position.
  2. Apply the park brake.

    3. Object Number: 1966259 Size: SH
  3. Remove the master cylinder nuts (1).

    4. Discard the master cylinder nuts.


    Object Number: 1966261 Size: SH
  4. Without disconnecting the brake pipes, remove and position aside the master cylinder (1).

    5. Support the master cylinder with heavy mechanics wire or equivalent.


    Object Number: 1892241 Size: SH
  5. Inspect the master cylinder seal (1) for damage and replace, if necessary.
  6. Disconnect the master cylinder primary piston position sensor electrical connector.
  7. Remove the master cylinder primary piston position sensor, if necessary. Refer to Brake Master Cylinder Primary Piston Position Sensor Replacement.

    8. Object Number: 1892248 Size: SH
  8. Remove the brake pushrod retainer bolt (1), if equipped.

    9. Object Number: 1892250 Size: SH
  9. Remove the brake pushrod retainer (1).

    10. Object Number: 1892252 Size: SH
  10. Slide the stoplamp switch (1) off of the brake pedal pushrod pin while simultaneously disconnecting the brake pushrod.

    11. Object Number: 1892257 Size: SH
  11. Remove the 4 brake pedal bracket nuts (1).

    12. Object Number: 1966263 Size: SH
  12. Remove the brake master cylinder adapter (1).
  13. Inspect the master cylinder adapter gasket for damage and replace, if necessary.

Installation Procedure

    Object Number: 1966263 Size: SH
  1. Install the master cylinder adapter gasket, if removed.
  2. Install the brake master cylinder adapter (1).

    3. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1892257 Size: SH
  3. Install the 4 brake pedal bracket nuts (1) and tighten to  25 N·m (18 lb ft).

    4. Object Number: 1892252 Size: SH
  4. Connect the brake pedal pushrod while simultaneously installing the stoplamp switch (1).

    5. Object Number: 1892250 Size: SH
  5. Install the brake pushrod retainer (1).

    6. Rotate the brake pushrod retainer 360 degrees to ensure the retainer is fully engaged in the brake pedal pushrod pivot pin groove.


    Object Number: 1892248 Size: SH
  6. Install the brake pushrod retainer bolt (1), if equipped and tighten to  10 N·m (89 lb in).

    7. Object Number: 1892241 Size: SH
  7. Install the master cylinder primary piston position sensor, if removed. Refer to Brake Master Cylinder Primary Piston Position Sensor Replacement.
  8. Connect the master cylinder primary piston position sensor electrical connector.
  9. Install the master cylinder seal (1), if removed.

    10. Ensure the brake master cylinder seal is fully seated in the groove on the master cylinder housing.


    Object Number: 1966261 Size: SH
  10. Position the master cylinder (1) to the master cylinder adapter.

    11. Object Number: 1966259 Size: SH
  11. Install 2 new master cylinder nuts (1) and tighten to  33 N·m (24 lb ft).