My Brake light flashes on an off

[ggt4]

Last week my brake light started flickering on and off at random. The brakes are good and the master cylinder has fluid. What could it be?

[HwyCruiser]

Is it the "BRAKE" or the "ABS" warning light on the instrument cluster lighting up?

If it's the "BRAKE" light, it just tells you when the emergency brake is engaged. Assuming the emergency brake pedal isn't just partially engaged (down), I'd guess the plunger-type switch on the emergency brake pedal bracket might be flaking out on you. The plunger might just need cleaning / lubricating.

[Drock96Marquis]

The Brake(!) Lamp will also illuminate if there is a problem with the hydraulic system, non-ABS related.


Most common cause is low fluid in the reservoir, it is very touchy about it.

Like HwyCruiser said, the emergency brake switch is also a somewhat common failure, take a look at it as well.

[Paul T. Casey]

The low fluid feature here is on the sensitive side also. The apparent "loss" from pad wear (appears the fluid is low) is enough to trigger this light. Happened to me, system checked out fine, and the issue went away with new pads.

[frdwrnch]

Sometimes the float in the master cylinder reservoir gets saturated or contaminated and doesn't float well. You can unplug the single wire at the park brake switch to rule that out(don't forget to release the park brake!) and see if the phantom light continues. If the reservoir is full and this continues then most likely the float is the culprit. Some Fords service only the reservoir, others only service the complete master cyl. Good Luck.

[wchain]

Tried applying parking brake and releasing?