Ford 2003 Mustang Workshop Manual page 524

connections between the power steering pump reservoir and
between the power steering pump reservoir and the hydro-boost
power brake booster.
Are there any obstructions?
F2 CHECK BOOSTER OPERATION
Have an assistant check the fluid in the power steering pump
reservoir while rapidly applying the brake pedal approximately one
inch.
Does the fluid show any movement or spouting?
PINPOINT TEST G: HYDRO-BOOST BRAKE SYSTEM OPERATION
SUSPECT
G1 CHECK BASIC OPERATION
Key in OFF position.
Press and release brake pedal several times to deplete all
hydraulic pressure from the hydro-boost power brake
booster.
Press and hold brake pedal with light pressure.
Key in START position.
Does the brake pedal fall slightly and hold, and is less
pressure now required to hold brake pedal at the new
position?
G2 CHECK FOR HYDRAULIC BRAKE LEAK
With engine running, press and release brake pedal several
times.
Hold brake pedal down with medium pressure, 34-47 Nm
(25-35 lb-ft).
Does brake pedal move toward floor?
G3 CHECK FOR LEAKS — BRAKE FLUID LINES
Check for leaks at brake lines, including brake master
cylinder and brake hose.
Do components check OK?
G4 CHECK HYDRO-BOOST CONNECTIONS
Clean the hydro-boost power brake booster, power steering
pressure hose, power steering gear pressure hose and
power steering return hose and connection.
Start engine and run at idle.
Check hose connections for leakage.
Do hose connections check OK?
G5 CHECK FOR HYDRO-BOOST LEAK
Test Step
REMOVE
obstructions or
INSTALL a new
hose.
No
GO to F2 .
Yes
System OK.
No
INSTALL a new
hydro-boost
assembly.
Result / Action to Take
Yes
Hydro-boost is OK.
No
GO to G2 .
Yes
GO to G3 .
No
GO to G4 .
Yes
COMPLETE master cylinder
By-Pass Condition Test in
this section.
No
INSTALL new hoses and
lines as necessary.
Yes
GO to G5 .
No
REPAIR or INSTALL new
hose and connections as
necessary.