88 F250"rear antilock" light on

[dan fitz]

have been driving this beast for a number of years and since we got it the dash has had this "rear antilock" light on. is this about antilock brakes or is it something to do with limited slip differential ? and do i need to be concerned that it's been on, am i missing something that i'll wish was working in a high speed stop or what.... any thoughts appreciated.

[rhandwor]

Originally Posted by dan fitz

have been driving this beast for a number of years and since we got it the dash has had this "rear antilock" light on. is this about antilock brakes or is it something to do with limited slip differential ? and do i need to be concerned that it's been on, am i missing something that i'll wish was working in a high speed stop or what.... any thoughts appreciated.

Some of these have a switch back by the frame in the rear. Try bleeding a rear brake bleeder and check if the light goes out. You can also try disconnecting the battery for 3 minutes.
If you have full time anti lock go somewhere and have the codes pulled.

[butch h]

There is a sensor mounted in the top of the rear axle housing. This is supposed to activate the RABS module (anti-lock unit) when conditions are such,that rearwheel lock up is imminent. There is a test connector under the hood,drivers side (at least on my '96 250 there is), that is used to flash the anti lock light. The number of flashes should point you in the direction,as to what the problem is.

[jyount]

The rabs on these trucks sucks even when it works. They are not modulated antilock like the new setups are. They are a dump valve only, completely not safe to say the least. If it senses a lock up is eminent its response is to "dump" rear brakes completely. I don't know what they do when the light is on, but if it works like standard brakes, take out the light and modulate it with your foot like the old school, safer anyway.

[FORDGUY09]

Mine was on for a while off and on found out it was the wire harness that plugs into the brake master cylinder and i replaced the wire harness with one used from the yard and spliced it in NO MORE LIGHT ON