Hydraulic System Bleeding

When any part of the hydraulic system has been disconnected for repair or replacement, air may get into the lines and cause spongy pedal action. This requires the bleeding of the hydraulic system after it has been properly connected to be sure all air is expelled from the brake cylinders and lines. The hydraulic system can be bled with pressure bleeding equipment such as Rotunda Brake Bleeder model 104-00064 or equivalent.

Bleed one brake cylinder at a time. On E-150-250-350, F-150-250-350 and Bronco vehicles, start the bleeding at the right rear brake wheel cylinder and then at the left rear wheel brake cylinder. After completing, proceed to the Rear Anti-lock Brake (RABS) Valve. Then proceed to bleed the front brakes, starting with the right front brake, and finish bleeding on the left front brake. On F-Super Duty vehicles, start the bleeding at the right rear brake, then the left rear brake. After completing, proceed to bleed the right front brake and then the left front brake. Keep the master cylinder reservoir filled with the specified Ford Heavy Duty Brake Fluid C6AZ-19542-AA or -BA (ESA-M6C25-A) or equivalent. Never use brake fluid that has been drained from the system.

Flashout Codes

Whenever the yellow REAR ABS light comes on during normal operation, a flashout code may be obtained to aid in problem diagnosis. If the vehicle is shut off before the code is read, the code will be lost. In some cases, the code may reappear when the vehicle is restarted. In other cases, the vehicle may have to be driven to reproduce the problem and, if the problem was associated with an intermittent condition, it may be difficult to reproduce. Therefore, whenever possible, it is recommended that the code be read before the vehicle is shut off.

WARNING:
PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.

NOTE:
If the red BRAKE light is also on, due to a grounding of the fluid level circuit (perhaps low brake fluid), no flashout code will be flashed and the REAR ABS light will remain on steadily.

NOTE:
If there is more than one system fault only the first recognized flashout code may be obtained.


Obtaining The Flashout Code

A flashout code may be obtainedonly when the yellow REAR ABS light is on. No code will be flashed if the system is OK. There are certain faults (those associated with the fluid level switch or loss of power to the module) that will cause the system to be deactivated and the REAR ABS light to be illuminated, but will not provide a diagnostic flashout code.

Before obtaining the flashout code, drive the vehicle to a level area, and place the shift lever in PARK for automatic transmissions and NEUTRAL for manual transmissions.

Notice whether the red BRAKE light is on or not (for future reference) and then apply the parking brake.

Keep the ignition key in the ON position so that the code will not be lost.

WARNING:
PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.

To obtain the flashout code, locate the RABS diagnostic connector (with the black/orange wire), and attach a jumper wire to it. Momentarily ground it to the chassis. When the ground is made and then broken, the REAR ABS light should begin to flash.

NOTE:
If the red BRAKE light was on (as noticed before the parking brake was applied), the problem may be with the low fluid level circuit and, in this case, no flashout code will be flashed and the light will remain on steadily.

The code consists of a number of short flashes and ends with a long flash. Count the short flashes and include the following long flash in the count to obtain the code number. For example, three short flashes followed by one long flash indicates Flashout Code Four. The code will continue to repeat itself until the key is turned off. It is recommended that the code be verified by reading it several times. In addition, the first code flashed may be too short because it may have been started in the middle. It should be ignored.