Hummer H2. Manual - part 799

Fig. 34: Exploded View Of Accumulator Components 
Courtesy of GENERAL MOTORS CORP. 

MASTER CYLINDER 

Removal 

1. Apply the park brake and block the wheels. Disconnect the electrical connector from the brake fluid level 

sensor. See Fig. 35 .  

2.  

Disconnect the brake pipes from the master cylinder. See Fig. 36 .  

3. Plug the open brake pipe ends. Remove the master cylinder mounting nuts. Remove the master cylinder 

from the vehicle. Remove the master cylinder reservoir. See MASTER CYLINDER RESERVOIR . 

NOTE:

Install a rubber cap or plug to the exposed brake pipe fitting ends in order 
to prevent brake fluid loss and contamination. 

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

Fig. 35: Disconnecting/Connecting Master Cylinder Electrical Connector 
Courtesy of GENERAL MOTORS CORP.

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

Fig. 36: Removing/Installing Master Cylinder 
Courtesy of GENERAL MOTORS CORP. 

Installation 

1. Install the master cylinder reservoir. See MASTER CYLINDER RESERVOIR . Bench bleed the 

master cylinder. See MASTER CYLINDER BENCH BLEEDING under BLEEDING BRAKE 
SYSTEM.  

2. Install the master cylinder to the vehicle. Install the master cylinder mounting nuts. Tighten the nuts to 

specification. See TORQUE SPECIFICATIONS . Remove the rubber cap or plug from the exposed 
brake pipe fitting ends.  

3. Connect the brake pipes. Tighten the fittings to specification. Connect the electrical connector to the 

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

brake fluid level sensor. Bleed the hydraulic brake system. See BLEEDING BRAKE SYSTEM . 
Release the park brake and unblock the wheels.  

MASTER CYLINDER FLUID LEVEL SENSOR 

Removal & Installation 

Disconnect the electrical connector from the fluid level sensor. Remove the fluid level sensor. See Fig. 37 . Use 
a needle nose pliers in order to compress the locking tabs at the opposite side of the master cylinder. To install, 
install the fluid level sensor until the locking tabs snap into place. Connect the electrical connector to the fluid 
level sensor.  

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer