W2 Check For Stuck Shut Valve or Leaky Outlet Valve

- Key OFF.

- Install 60-Pin Breakout Box 014-00322 or equivalent and the correct Econoline 4WABS overlay.

- Jumper Pins: (1 and 3), (30 and 14) and (31 and 27) together on the 60-pin breakout box.

- Raise vehicle so front right wheel is just off the ground.

NOTE: The leaky dump valve is similar to the master cylinder bypass condition. It is important that the pedal be quickly and forcefully applied to rule out master cylinder bypass as a cause if a hydraulic leak is detected. Typically, master cylinder bypass occurs only at low pedal apply rates and low line pressures.

- Press hard on the brake pedal and have an assistant try to turn the right front wheel.

- Does the wheel turn or the pedal drop slowly?

YES -- Replace HCU. PERFORM Zero Speed ABS Test using New Generation Star (NGS) tester. Go to Pinpoint Test Z to verify concern is resolved. Z Drive Test

NO -- Go to W3. W3 Check Front Right Isolation Valve Operation