1987 F-150 Rear Antilock Light

[Mmatto99]

My 87 F-150 rear antilock light was coming on and off every now and again, but now it is on all the time...Any help w/ what it could be.Thanks

[pashadowops]

I had the same problem on my '88. It turned out to be a blown wheel cylinder. Once I replaced it and adjusted the brakes, the light went out. I would also check out the porter valve located on the chassis on the driver side rail. Sometimes they get hit by debris when off roading. Just a thought.

[Point Blank]

Mine lights up when fluid is low,check..

[msgdew]

Had same problem on 89, replaced the bad sensor at rear pumpkin and light went out, anti lock sysstem works fine.

[MERC_DoD]

I ran a hot wire from the battery to under rear axle after replacing the pumkin sensor and then pulled off the connector for the speed sensor. I hooked my 12 volt tester to one end of hot wire from battery and the sharp end to ground side of connector with no result. When wiggling another connector (the one at axle/frame junction) the test light came on. I cut out the connector and spliced the wires together with butt splice crimp connector and things seem to be ok now. At least on the first two test drives. I've been chasing this intermittent problem for a long time now. Wish me luck!