ABS problem

[Z Ya Later]

I'm looking at buying a 93 Z28 from a guy at work. Runs strong, needs a new clutch (current is original with 101,600 mi.) and new front rotors...no biggie. But, the ABS is also acting up. He's said he had this problem before and had the the ABS sensor replaced. But, it only lasted 3 weeks before this happened again. Before, it would be fine until you were slowing down and got down to about 5...then the brakes would not work at all for about 2 sec. and then kick in again with the Low Trac light coming on. Eventually, the ABS Inop light just stayed on and the brakes work fine again. Any ideas? Also, I'm wondering if there is a scanner that will work on it. Thanks.

[Injuneer]

I've had a very similar problem when the rear ABS sensor on my Strange 12-bolt got out of adjustment. The car would slow to about 5mph, the ABS would pulse and the car would take a few extra feet to stop. Check the rear sensor again, including the wiring harness. I would check the sensor itself to make sure it isn't all crudded up... shouldn't affect it, but who knows.

To scan the ABS control module, you need a "professional" level scanner like the factory Tech and OTC units, or something like the Snap-On unit. Any good brake shop should have a scanner. If you meant "scan the engine/ECM" you can use an AutoXray unit, but it will not read the ABS or BCM modules.

[Z Ya Later]

The current owner said that the front right sensor had to be replaced and then it went away for about 3 weeks. I know this is going to sound stupid, but does each wheel have its own ABS sensor or is it just one on each "axle", so to speak? Thanks for the help.

[4THGEN Z]

93's didn't have TCS available yet so there is one sensor for each front wheel (integrated into the front hub assembly) and 1 sensor for the rear mounted in the top of the diff housing as Fred mentioned.

[Z Ya Later]

Ok...so, in other words, expect to shell out some money?

[Joe 1320]

Originally posted by Steve93Z
Ok...so, in other words, expect to shell out some money?

Perhaps not. Before you shell out anything, pull each connector and make sure everything is really clean and dry, make sure all the connections are tight. Then if it doesn't work, prepare to spend $$. I might be able to help you out if it ends up being the front hubs. I replaced mine just to freshen up the front end even though there was nothing wrong with them, let me know when the time comes and I'll send them to you cheap.

[pete]

I've been running with the ABS Lite on for a couple of years, true, no ABS fuctions, but regular brakes operate fine. 230k miles, and still good.

[Z Ya Later]

Thanks Joe. Is there any way to check out the connections without having to dig into the hub and, preferably, without having to pull off the wheels? Seeing as she isn't mine just yet, I want to do as little work as humanly possible lol. Thanks again to everybody who has been posting to my problem so far.

[Z Ya Later]

The brakes are working fine, except that the rotors need to be replaced in the front as the vehicle shudders when hitting the brakes at high speeds due to the grooves and such. I just prefer to have everything in perfect working order if possible.

[Joe 1320]

The hub is really simple. The spindle has a large hole on the center, the hub is centered into the hole and attached by four bolts. the backside of the hole is accessable without having to remove the wheel or the hub. Drive the car up onto ramps or jack it up and secure with jacstands. Crawl under the car and you'll see the electrical connector going into the back of the hub. A really simple design. The only bummer is that the ABS sensor is not servicable, the whole hub bearing assembly must be replaced.

[Z Ya Later]

So, if it is the sensor, the whole friggen hub has to be replaced? What if its the one in the rear? Or do I want to know?

[Joe 1320]

If the front sensor is bad, you must replace the hub. If memory serves, they are roughly $130 per hub. Now, the one in the rear is a different story..... The sensor is mounted on top of the differential and can be replaced. There is one more part to the equation and it's the reluctor ring, located inside the rear. Doubtful that is the problem though.

[Z Ya Later]

So, I would have to get the hub, new bearings, the grease and the tools to replace the hub should it be one of the front hubs?

[Joe 1320]

Originally posted by Steve93Z
So, I would have to get the hub, new bearings, the grease and the tools to replace the hub should it be one of the front hubs?

Yes, no, no, perhaps.

The hub is a sealed assembly. It contains the bearings, abs sensor and wheels studs. The proceedure goes like this:

Loosten the front lug nuts, jack up the car and secure on stands. Remove the front wheel(s), unplug abs harness from the hub, remove the caliper bolts and secure caliper out of the way with a coat hanger. Slide the front rotor(s) off the wheel studs, remove the 4 bolts that secure the hub to the spindle. Install the new hub and reassemble in the reverse order. That's it bro. A really simple fix.

[Z Ya Later]

Man I wish my Jeep was that easy lol. But, if its not the sensors or the reluctor ring, is there something else that it could be? Thanks for the major guidance.