'93 F-150 V8 dash ABS light sensor

In the past, when the ABS light on the dash went on, it was that the brake master cylinder fluid level had dropped a hair below the 'fill to' line. Lately the light comes on and stays on and the master cylinder is filled just above the 'fill to' line. Does anyone know how the sensor works that determines if the master cylinder is low on fluid? Opened the cap on the master cylinder and there is a small circular item floating in the brake fluid. Is this the sensor? If so, how does it work?

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Oldblu, I'm sure others will encounter this same question in the future. Is the information in a format that you could post it here so others who search the forum may get their answer easily?

-Rod

Oldblu, I'm sure others will encounter this same question in the future. Is the information in a format that you could post it here so others who search the forum may get their answer easily?

-Rod

You are very correct ! I too am having such a problem as bf5113 , only mine is a '97 F-250 .... Would have liked to have the info but I guess I'll keep looking else where .

After not finding an answer to solve my ABS light problem, I decided to hook up my code reader to check for any system error codes. All that displayed was "111", the code for test pass. Ran the test several times getting the same result. Since then the ABS light has not come on while driving the truck. Don't know if hooking up the OBD reader did anything to clear the problem.

Interesting experience. Generally the ABS system is independent of the Powertrain Control Module (PCM) and not accessible by commercially available scan tools, even on today's OBD-II vehicles. In the early '90's a technician often needed either a special adapter cable to plug in to a special ABS diagnostic connector or in some cases just a test light, jumper wire, or screwdriver to turn a switch and watch an LED blink.

For the 1997 F-150 special software in a professional scan tool, or a dedicated ABS and airbag scan tool is required to access the diagnostic codes of the ABS system as well as real time sensor information.

-Rod

I'm the original poster of this issue. As a follow up, this past weekend not only did the ABS light come on, but the red brake light on the dash came on and the brake fluid reservoir was down quite a bit. Had my mechanic check it out and it turns out brake fluid was squirting from a rear brake line very time the brake pedal was depressed. Had both rear brake lines replaced and so far, the ABS light is staying off. I pass this on in case anyone else has a similar ABS light problem, you may want to check the brake lines for leakage.