Gentlemen: today I was driving along and I had to stand on my brakes really hard just before I stopped I noticed what I thought was my ABS Brake motor come on. When I got home I looked under the hood I couldn’t find an ABS motor I seem to only have two lines coming out of my master cylinder and going down toward the frame. also I played with the brakes a little bit coming home and tried stopping really hard from a slow speed and it seems like my rear wheels was letting go each time. I DID A little research and found out I got a rear wheel speed sensor on the differential but I’m not clear on whether I’ve got front wheel ABS or not. Hopefully you guys who know all about these brake systems will chime in here and tell me what I got and what may be wrong. The truck is a 1997 Ranger XLT with a 3.0 automatic. I redid the brake pads and rotors and drums six or eight months ago but I don’t remember any sensors or wires, maybe they were there and I just didn’t notice.
Thanks in advance, Larry

 

You have RABS(rear anti-lock brake system), your ABS module is in drivers side frame rail just below firewall, follow the FRONT brake line from the master

4WABS(4 wheel abs) is very noticeable in Ranger engine bay drivers side, next to Master, 2 brake lines in 3 brake lines out

RABS just has the one sensor on rear axle so a wheel can still lock up, its better than no ABS in a pickup truck but many by-pass it if it has a problem

If you overheat front rotor they will warp, even new ones, this causes a pulsing in brake pedal when braking, only fix is to replace rotors, turning does work well on these rotors, they are already too thin, they just warp faster if you make them thinner
Its safe to drive with warped rotor unless it gets very bad

 

It’s not the front rotors they are smooth what it is is the rear wheels just let loose and then grab again. On and off brakes. They don’t do it every time mostly when I am slow to a stop maybe 5 miles an hour worst if I’m on a downgrade. I’m hoping the sensor is just sludged up maybe with little metal and sludge. It doesn’t do it at high-speed just right before you stop. I first thought it was a wheel sliding when I would go across a painted line on the street. Brakes are very smooth and effective until it slows down almost to a stop. I’m going to try a new sensor back there and see if that fixes it if it doesn’t I’ll probably just bypass it. Find me I don’t have are you all light. Can you tell me how to bypass the RABS?

Larry

 

Does the ABS light come on when braking?
It should if pulsing was from ABS Module

ABS light should come on with key on and then go off, that means bulb is OK

RABS module just has brake line in and line out, to by-pass you should get an adjustable proportioning valve
Then hook it up to the in and out lines
Bleed rear brake system
You adjust it so rear brakes don't lock up too much when stopping, front brakes should get about 70% and rear 30% in a pickup truck

You can just connect in and out lines together, to by-pass as well, but rear brakes may tend to lock up on hard stops

 

Thanks a mill had read a couple of posts and you’re the first one to mention the adjustable proportioning valve thank you
Larry

ps: Light does Flickr does not come on all the full cuz going so slow hardly pulsates.

 

The RABS on Rangers just uses that one sensor so it can't "see" if one wheel locks up, and it bases activation of ABS valve on sudden drop of the pulses from that one sensor
So changing the sensor is not expensive or a bad idea, it takes that off the table
Check to make sure wires are OK, not frayed, and inside connector looks clean, no corrosion

That sensor is a VR type sensor, so generates its own AC Voltage, 0.5 to 6vAC, the RABS module uses that voltage to see 25,000ppm(pulses per mile)