I know the 92+ models are supposed to have a very primitive anti-lock braking system on the rear brakes.  Should I feel a pulsing sensation when the brakes lock like on newer ABS system?  How can I tell if the system is working?

I have that very question, but there is a different motor in mine. some of the wires might be cut.

I've been driving these beasties on ice and snow since the first models with ABS, and no, you can't feel it in the pedals.  Also, as far as I can tell, the ABS doesn't work either.  I can't say I've EVER felt that the ABS Engaged.  It works great on my wife's 99 Grand Vitara though.

I drove a Cavalier in the early 90's that had rear wheel anti-lock and I could feel it pulsing.

is there a way to get rid of it?

That's weird I've owned 2 trackers with ABS and both of them i can feel when it's working.  Sometimes they even work in situation where i'm surprised that they are working...like slowing down to pull into a gas station.  As I slow down and turn in my brakes pulse.  Or i can feel the ABS resetting sometimes at stop lights.  I'll be sitting at a light stopped and my brake pedal goes limp and presses down more.  It works, just last year it saved my ass big time when i started spinning on an icy highway.

is there a way to get rid of it?

Disconnect the connector to the rear diff, I guess would do the trick.

I know the 92+ models are supposed to have a very primitive anti-lock braking system on the rear brakes.  Should I feel a pulsing sensation when the brakes lock like on newer ABS system?  How can I tell if the system is working?

You're right about the "primitive" anti-lock system.  There's a valve in the rear brake line that attaches solidly to either the body or frame (don't recall), and then to the axle via a light spring.  When there's weight in the back of the truck, the spring doesn't pull on the valve, and full braking pressure is delivered to the rear wheels.  When there is not much weight in the back of the truck, the axle pulls on the spring, which pulls on the valve, which lessens braking pressure to the rear.

I doubt you'd be able to sense from the driver's seat whether or not it's working.  I never could.  But there probably is a procedure to static-test it in the shop.

There's a valve in the rear brake line that attaches solidly to either the body or frame (don't recall), and then to the axle via a light spring.  When there's weight in the back of the truck, the spring doesn't pull on the valve, and full braking pressure is delivered to the rear wheels.  When there is not much weight in the back of the truck, the axle pulls on the spring, which pulls on the valve, which lessens braking pressure to the rear.

I don't think that's the same as the ABS.  There's a toothed "interrupter wheel" in the rear diff (maybe 32 teeth on it?), and a hall-effect pick-up sensor, that feeds the signal from the interrupter wheel to a "brake modulator"...I guess that's mounted on the firewall...which is SUPPOSED to give you pulsed braking, when the rear wheel locks up (and the signal from the interrupter STOPS).

Arguably, when this happens, the modulator should REDUCE the braking pressure to the rear wheels, until the "locked" condition stops.  On dry roads, I would expect to see a skid-mark like a dashed line from the interaction of the brake modulator going in and out of the locked state.  I've never seen, nor felt such a modulation of the braking action, in panic-braking conditions (which is when you need it most).

Now the GV is MUCH different.  When you fire it up, you get about a second "self-test" of the ABS system, and you hear it, and feel it in the pedals.  You do anything more than breathe on the brakes on ice, and the ABS kicks in immediately, and it really works.  My first experience with ABS was on slightly larger vehicles - the 100,000 pound F-111 aircraft stopped entirely with brakes.  No chutes, no thrust reversers, just massive brakes, and ABS that kept the wheels from locking up on all kinds of runway conditions.

Quote from: beercheck on December 09, 2009, 12:54:49 PM

There's a valve in the rear brake line that attaches solidly to either the body or frame (don't recall), and then to the axle via a light spring.  When there's weight in the back of the truck, the spring doesn't pull on the valve, and full braking pressure is delivered to the rear wheels.  When there is not much weight in the back of the truck, the axle pulls on the spring, which pulls on the valve, which lessens braking pressure to the rear.

I don't think that's the same as the ABS.  There's a toothed "interrupter wheel" in the rear diff (maybe 32 teeth on it?), and a hall-effect pick-up sensor, that feeds the signal from the interrupter wheel to a "brake modulator"...I guess that's mounted on the firewall...which is SUPPOSED to give you pulsed braking, when the rear wheel locks up (and the signal from the interrupter STOPS).

Ah.  My '96 SWB Tracker had the type I described, nothing like real ABS.  I didn't realize any had that!

These things have rear brakes?     

i changed my rear diff over to one that didn't have the abs ring. I had to make a panic stop sometime after and the  fronts locked up, but the rears didn't. the brakes all around were good. I'm thinking that it would only really work on ice or snow. although i never had a problem.

I found out that my rear brakes dont work much. with the rear axle in the air and the automatic tranny in drive, the brakes almost dont stop the tire from spinng.

That's weird I've owned 2 trackers with ABS and both of them i can feel when it's working.  Sometimes they even work in situation where i'm surprised that they are working...like slowing down to pull into a gas station.  As I slow down and turn in my brakes pulse.  Or i can feel the ABS resetting sometimes at stop lights.  I'll be sitting at a light stopped and my brake pedal goes limp and presses down more.  It works, just last year it saved my ass big time when i started spinning on an icy highway.

Hey Jooky, it sounds like you may have a problem with the abs system causing false activation, you should only feel it kick in when there is a tire sliding, and never when you're sitting stopped.

when I had the 93 kick I could feel it when i was going about 50 mph or faster and then stopping.