Ford F150 Pickup. Instruction - part 433

Fig. 90: Removing Brake Master Cylinder Fluid Control Valve 
Courtesy of FORD MOTOR CO. 

6. Remove the primary piston assembly (2169). 

1. Depress the primary piston and remove the snap ring.  

2. Remove and discard the primary piston assembly. 

 

2003 Ford Pickup F150 

2003 BRAKES Hydraulic Brake Actuation - F150 Pickup

  

Fig. 91: Removing Primary Piston Assembly 
Courtesy of FORD MOTOR CO. 

7. Remove the secondary piston assembly (2A502). 

1. Plug the rear outlet port and, if necessary, plug the brake pressure switch port.  

2. Apply compressed air into the front outlet port and remove the secondary piston assembly and 

discard.  

 

2003 Ford Pickup F150 

2003 BRAKES Hydraulic Brake Actuation - F150 Pickup

  

Fig. 92: Identifying Master Cylinder Ports 
Courtesy of FORD MOTOR CO. 

NOTE:

If the brake master cylinder bore is damaged, the brake master cylinder 
must be installed new.

 

2003 Ford Pickup F150 

2003 BRAKES Hydraulic Brake Actuation - F150 Pickup

  

Fig. 93: Inspecting Brake Master Cylinder Bore 
Courtesy of FORD MOTOR CO. 

8. Use isopropyl alcohol to clean and inspect the brake master cylinder bore for damage.  

Assembly 

1. Use clean High-Performance DOT 3 Brake Fluid C6AZ-19542-AB or equivalent DOT 3 fluid meeting 

Ford specification ESA-M6C25-A, to lubricate the new piston assembly seals.  

2. Carefully install the secondary piston assembly. 

WARNING:

Use of any other than approved DOT 3 brake fluid will cause permanent 
damage to brake components and will render the brakes inoperative.

WARNING:

Brake fluid contains polyglycol ethers and polyglycols. Avoid contact 
with eyes. Wash hands thoroughly after handling. If brake fluid contacts 
eyes, flush eyes with running water for 15 minutes. Get medical attention 
if irritation persists. If taken internally, drink water and induce vomiting. 
Get medical attention immediately.

CAUTION: Brake fluid is harmful to painted or plastic surfaces. If brake fluid is spilled 

onto a painted or plastic surface, immediately wash it with water.

 

2003 Ford Pickup F150 

2003 BRAKES Hydraulic Brake Actuation - F150 Pickup