Hummer H2. Manual - part 800

Fig. 37: Removing/Installing Master Cylinder Fluid Level Sensor 
Courtesy of GENERAL MOTORS CORP. 

MASTER CYLINDER RESERVOIR 

CAUTION: Brake fluid may irritate eyes and skin. In case of contact, take the 

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

Removal 

1. Apply the park brake and block the wheels. Remove the master cylinder. See MASTER CYLINDER . 

Drain the master cylinder reservoir.  

2. Secure the master cylinder in a vise. DO NOT clamp the master cylinder body, secure only at the flange. 

Remove the brake fluid level sensor by carefully depressing the retaining tabs and pushing the sensor 
through the reservoir.  

3. Carefully remove the reservoir retaining pins. Remove the reservoir from the master cylinder by pulling 

the reservoir straight up and away from the cylinder. See Fig. 38 . Remove the seals from the master 
cylinder.  

following actions: Eye contact; rinse thoroughly with water. Skin contact; 
wash with soap and water. If ingested; consult a physician immediately. 

NOTE:

Avoid spilling brake fluid onto painted surfaces, electrical connections, wiring, 
or cables. Brake fluid will damage painted surfaces and cause corrosion to 
electrical components. If any brake fluid comes in contact with painted 
surfaces, immediately flush the area with water. If any brake fluid comes in 
contact with electrical connections, wiring, or cables, use a clean shop cloth to 
wipe away the fluid. 

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer

  

Fig. 38: Removing & Installing Master Cylinder Reservoir 
Courtesy of GENERAL MOTORS CORP. 

Installation 

1. Inspect the reservoir for cracks or deformation. If found, replace the reservoir. Clean the reservoir with 

denatured alcohol, or equivalent. Dry the reservoir with non-lubricated, filtered air.  

2. Lubricate the NEW seals and the outer surface area of the reservoir-to-housing barrels with Delco 

Supreme 11(R) (GM P/N 12377967) or equivalent DOT-3 brake fluid, from a clean, sealed brake fluid 
container. Install the lubricated seals, make sure they are fully seated.  

3. Install the reservoir to the master cylinder by pressing the reservoir straight down on the master cylinder 

until the pin holes are aligned. See Fig. 38 . Carefully install the reservoir retaining pins to secure the 
reservoir. Place the brake fluid level sensor into the reservoir, press into place to secure the sensor 
retaining tabs. Remove the master cylinder from the vice.  

4. Install the master cylinder. See MASTER CYLINDER . Release the park brake. Bleed the hydraulic 

brake system. See BLEEDING BRAKE SYSTEM .  

STOP LIGHT SWITCH 

Removal & Installation 

Disconnect the electrical connector from the stop light switch. Remove the pushrod retaining clip. Remove the 
stop light switch. Install the stop light switch. Install the pushrod retaining clip. Connect the electrical connector 
to the stop light switch. See Fig. 39 .  

 

2004 Hummer H2 

2003-04 BRAKES Disc - Hummer