'97 Explorer ABS kicks in suddenly when stopping

[Ilikemice]

So originally I thought I was just hitting the brakes too hard but even if I crawl to a stop the brake will judder like crazy and make the electric motor sound just as I'm about to actually stop. Fluid is fine, no warning lights and otherwise the brakes work fine. Just a bit annoying.

Cheers!

 

[Sasquatch_Ryda]

You've got a front speed sensor going bad. Take it in get it put on the scanner and have them monitor the PIDS on the speed sensors to see which one is going bad.

 

[Ilikemice]

Perfect answer. Thanks a lot!

Edit: You're a Ford tech, right? Is it an expensive job?

 

[Sasquatch_Ryda]

Well it can be the sensor, or the exciter ring that is built into the bearing/hub assembly or both.

Not too sure on the prices of the parts, don't really pay all that much attention to the prices at work.

 

[Ilikemice]

I took it to the dealership and they said the left side front sensor was dirty. Because of rust it'd take them four hours to get to the sensor to clean it. This is like, hundreds in labour costs alone.

Is it possible for me to pick up a Chilton's or Haynes manual and get this done myself? I could probably get it apart but I'm not sure what to look for.

I'm going to be replacing the rotors and pads all round. Is the sensor something I can get to while doing that?

 

[Sasquatch_Ryda]

If its that rusty, the sensor will probably break on inside the wheel bearing anyway up trying to remove it. I'd just replace the wheel bearing, it will come with a new sensor in it.

Grab a manual, its not hard to change a wheel bearing.

 

[Ilikemice]

I got the sensor out. Four hour job my arse. It was a bit grubby but the front brake is binding like mad. Time for new rotors/pads!

 

[Earl43P]

I suggest you see how much harder that side's pistons are to push back into the caliper when you replace the pads. Could be a bad flex hose, acting like a check valve. This is ASSUMING that you won't crack the bleeder for that task, which most people don't (so they don't have to bleed).

I suggest you buy Carquest mid-grade or above pads, so they will come with the new metal pieces for the pad/caliper build-up. Grease these metal pieces' sliding surfaces.

I suggest you seperate the caliper halves and clean and lube the slider pins.

Sounds like your ABS MAY be just fine and it was reacting to and masking a bad front brake problem. You'll also be pleasantly surprised by Carquest's price on Explorer rotors. I think they were $30 each when I did my 99 a month ago. I know the whole price for pads and two rotors was <$100, I kid you not!

 

[Ilikemice]

i'm going with some ebay rotors and pads for real cheap. what grease do i use? that copper slip stuff? cheers for the info

 

[Sasquatch_Ryda]

Brake caliper and slide pin grease

 

[Ilikemice]

Makes sense. Thanks.

 

[Bill]

At $30 per rotor, they are very likely made in China junk. Sure, they are cheap, but they will wear much faster than something worth what they cost. I know people that have warped these rotors from the heat generated from going down a long grade in California summers. At that point you will have to replace the rotors again and the total cost will be $60.00 a rotor, plus your time and frustration.

Additionally, a good friend of mine bought some of the cheapo rotors Raybestos carries for their econo-line and the tone rings were slightly different between each side, causing the same problem you are experiencing.

At any rate, it would be a good idea to see if you need to replace the rotors before spending the money on them.

Cheap pads will gas-out if they get hot causing brake-fade.

The causes of your problem, based on what I've seen:

A combination of dirt and metallic particles covering the surface of the sensor. Easy fix is to clean the sensor.

Dirt, grease and metallic particles on the ABS tone ring. Clean the tone ring.

The tone ring can also become warped or bent. I have no idea how this happens. Maybe it is heat, maybe a rock or something strikes it while going down the freeway, but it would seem unlikely. You can replace the tone ring, but pressing the new tone ring in the rotor isn't the easiest thing to do without warping the tone ring. The rotor is usually replaced.

And of course, the sensor can fail.

 

[Ilikemice]

I just replaced the front rotors and pads, the left side sensor was clean but it still pulls to the right as soon as the ABS kicks in. I'll go out now and try to get to the right hand ABS sensor to see what state that's in. It's about the only thing I haven't checked.

Just checked the other sensor and cleaned it and still no joy. Now obviously I want this fixed, but I also need the car to drive about in. I'll buy a new sensor ASAP but can I pull the ABS fuse and run about without the ABS? It has its inspection in October so the ABS has to be all working then, so it's not like I want to bodge it for good. I'm just fed up of my stopping distance going to crap.

Or shall I just take the Blazer out of storage?


[edit again] Oh. Am I alright getting an ebay sensor? It's about the only place I can get one that ships here without having to go to the dealership. They work on either wheel, right?