Some 1999-2008 Ford F-Super Duty trucks equipped with the Hydro-Boost brake booster system may exhibit a brake pedal kickback and/or grabbing condition when applying the brakes. This may be caused by contamination within the power steering system.
1. Verify that the line from the pump and the line to the gear at the Hydro-Boost are not crossed. The passenger side goes to the pump and the driver side goes to the gear.
a. Attach a pinch-off clamp to the lower power steering hose approximately 6 inches from the lower port of the power steering cooler to keep fluid from emptying out of the system when the hose is disconnected.
2. Disconnect the power steering hose from the lower port on the cooler. Cap the cooler port to minimize fluid leakage and immediately install a temporary filter in line with the power steering hose using hose clamps to retain the filter (the filter needs to go in the low pressure line that runs from the gear to the cooler to the reservoir).
3. Attach the other end of the filter to the cooler using hose clamps.
4. Remove the pinch-off clamp from the power steering hose.
Make sure that the parking brake is applied during the following steps.
1. Check the power steering fluid level before starting the engine.
2. Start the engine and allow it to idle for approximately 15 seconds.
3. Turn the steering wheel lock-to-lock 10 times (DO NOT hold the steering at lock for more than 5 seconds).
4. Pump the brake pedal hard to the floor 25 times.
5. Turn the steering wheel lock-to-lock 5 times.
6. Remove the filter and reconnect the power steering line to the cooler. Discard the filter. Fill the power steering system.
7. With the engine at idle, gradually apply the brake pedal until fully applied. If the pedal kickback persists, replace the Hydro-Boost brake booster. Refer to the workshop manual, section 206-07.
XC3Z-7B155-BA………….Power steering fluid filter
5C7Z-2005-AA……………Hydro-Boost 1999-2004 F-Super Duty
6C3Z-2005-AA……………Hydro-Boost 2005-2007 F-Super Duty
7C3Z-2005-AA……………Hydro-Boost 2008 F-Super Duty