Pinpoint Test G: Testing
WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
- G1 CHECK BASE BRAKE COMPONENTS
- Visually inspect the brake lines from the hydraulic control unit (HCU) to the wheel cylinders.
- Visually inspect the calipers and the brake components.
- Are any of these components damaged or leaking?
- Yes : REPAIR as necessary. REFER to BRAKE SYSTEM-GENERAL INFORMATION to continue diagnosis of the base brake system.
- No : GO to G2.
- G2 CHECK FOR LEAKING DUMP VALVE
- Key in START position.
- Remove the rubber caps from the two HCU low pressure accumulators and insert a clean steel implement (such as a paper clip) into each low pressure accumulator.
- Have an assistant press hard on the brake pedal while observing the steel implements.
- Do any of the steel implements move out 12.7 mm (0.5 in) or more?
NOTE: A leaking dump valve is similar to the master cylinder bypass condition. It is important that the pedal be quickly and forcefully applied to rule out the master cylinder bypass as a cause. Typically a master cylinder bypass occurs only at low pedal pressure rates and low tire pressures.- Yes : INSTALL a new HCU. REFER to HYDRAULIC CONTROL UNIT (HCU) .
- No : System is operating correctly at this time. REMOVE the steel implements and INSTALL the rubber caps. CLEAR the DTCs. DRIVE the vehicle over rough roads. REPEAT the self-test. TEST the system for normal operation.