2003 FORD MUSTANG Workshop Manual

Page 521 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST C: BRAKE LOCKUP DURING LIGHT BRAKE PEDAL 
FORCE  �z
Is the resistance greater than 10,000 ohms?  No 
REPAIR the ground short in 
circuit 128 (VT/YE). TEST the 
system for normal operatio

Page 522 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST D: EXCESSIVE/ERRATIC BRAKE PEDAL TRAVEL 
PINPOINT TEST E: HYDRO-
BOOST, NO POWER ASSIST 4481 kPa (510-
650 psi)?  INSTALL a new proportioning valve. 
RETEST for normal operation. 
Test S

Page 523 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST F: HYDRO-
BOOST ERRATIC OPERATION, STICKS, 
BINDS OR GRABS  �z
Check accessory drive belt tension and 
condition. Refer to  Section 303 - 05  . 
�z Is the accessory drive belt OK?  Yes

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FORD MUSTANG 2003  Workshop Manual PINPOINT TEST G: HYDRO-
BOOST BRAKE SYSTEM OPERATION 
SUSPECT  connections between the power steering pump reservoir and 
between the power steering pump reservoir and the hydro-
boost 
power brake bo

Page 525 of 4378

FORD MUSTANG 2003  Workshop Manual Component Tests 
Brake Booster 
1. Check the hydraulic brake system for leaks or insufficient fluid. 
2. With the transmission (7003) in NEUTRAL, stop the engine (6007) and apply the parking brake  co

Page 526 of 4378

FORD MUSTANG 2003  Workshop Manual The function of the power brake booster check valve is to allow manifold vacuum to enter the power 
brake booster and prevent the escape of vacuum in case manifold vacuum is lost during sustained full

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FORD MUSTANG 2003  Workshop Manual Turbulence seen in the brake master cylinder reservoir upon application or release of the brake pedal 
is normal and shows that the compensating ports are not plugged.  Klj .  15 ba
  152003 Must

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FORD MUSTANG 2003  Workshop Manual GENERAL PROCEDURES 
Bleeding —
Components 
Master Cylinder Priming — In-Vehicle or Bench 
 WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with 
eyes. Wash hands tho