ABS grinding - no brake

[superchef]

The problem started 2 weeks ago. Periodically when I hit my brake pedal it vibrates under my foot and the brakes don't engage unless I lift my foot and hit the pedal again. Kinda scary. Best way I can describe the feeling under the foot - imagine a manual tranny - trying to put it into gear with the engine running and not using the clutch. The gear grinding vibe on your palm is pretty much what I feel under my foot.
The ABS light only comes on when I turn on the ignition(power up testing) but no other time.
Since this started I have replaced pads in front as well as shoes and spring kit in rear.
This is a 93 XLT. I have not felt the ABS wrk since I purchased it in Feb.
If anyone has any thoughts or suggestions - it would be greatly appreciated. I don't want to let my wife drive this thing until I can get this figured out.

Rick

 

[puddle jumper]

my 93 has done the same exact thing more than a few times !! sometimes when im turning and brakeing at the same time ( like pulling into a parking spot ) and sometimes just sitting still in traffic at a red light , the abs light will come on, it even has come on while sitting still just warming up in the mornings before i even put it in gear . have you gotten anywhere with solveing this problem yet ?i have been going through all the posts on this subject looking for clues and so far it looks like maybe a bad sensor

 

[performancenut]

ABS sensor replacement is usually the least expensive fix. If the module goes bad, pony-up for some big bucks.

 

[DeRocha]

The vibration is the ABS controller rapidly pumping the brakes as one of its sensors indicated a wheel was "locking up". I haven't had this problem, but you could pull the ABS fuse which will prevent the ABS from kicking in...

 

[BuffaloXplorer]

I've got a '96 XLT and on occasion, i get a similar feeling, as if the brakes aren't working. My problem lies in faulty calipers. When the caliper doesn't return to it's original position (off of the disc), I've got to pump the pedal to get it to "come back to life." I usually do a quick pump to get it to come back and then they seem tighter than before. I'd check your calipers and/or your slide rails. I also noticed that without the metal slide mounted on the caliper bracket, the pads catch from time to time and aren't applied correctly. Just my 2-cents.

 

[Bacardi Mike]

Periodically when I hit my brake pedal it vibrates under my foot and the brakes don't engage unless I lift my foot and hit the pedal again.

Mine does the exact sane thing. Been doing it the day I did my front brakes. Where is the ABS sensor located?

 

[mrboyle]

I've got a '96 XLT and on occasion, i get a similar feeling, as if the brakes aren't working. My problem lies in faulty calipers. When the caliper doesn't return to it's original position (off of the disc), I've got to pump the pedal to get it to "come back to life." I usually do a quick pump to get it to come back and then they seem tighter than before. I'd check your calipers and/or your slide rails. I also noticed that without the metal slide mounted on the caliper bracket, the pads catch from time to time and aren't applied correctly. Just my 2-cents.

I'm sorry to be rude, but this does not make any sense.
I don't see how calipers can cause the symptoms you desribe. Due to its design the piston in the caliper can not move far enough from the pads to make pumping the brakes necessary. The piston rides on a suqare seal inside the caliper. When you apply the brakes the piston is forced to slide aginst this seal causing it to rock and create resistance aginst the piston. When you release the pedal the tension in the seal will force the piston to retract into the caliper. The catch is, the piston will only retract until the seal returns to a netural position (and no further). The only thing that can cause the piston to retract any further is outside force (typically created by warpped rotors).
Ok, now that being said, I think your problem is actually in the master cylinder. More specifically the quick take up valve.

Mine does the exact sane thing. Been doing it the day I did my front brakes. Where is the ABS sensor located?

The front ABS sensors on a 2nd generation X are attached to the wheel bearing hub and are isolated form any outside contamination.

The one thing I'd recomend anyone experiencing the problems you are all having is to remove and clean the rear ABS sensor (located in the rear diff). The sensor is magnet and over time any metal particles floating in the gear oil will attach themselves to the sensor and cause it to read erraticaly. The problem is worse on rear ends equipped with limited lips. This may not cure the problem for everyone, but I have found it to work on many different vehicles.

 

[y2kjackal]

Right hand turn too

My 95 XLT has had this issue with the ABS kicking in on a slow right hand turn like into a parking space. Lately, it is at a low speed stop, too.

My main question is, can the front sensors be removed and cleaned?

Also, do I need to remove the rotor to clean anything? Is there a proceedure somewhere for rotor removal?

 

[crazyfoolreal]

my 93 does this all the time and Ive grown accustom to it, usually i have abs showin up on my dash under the speedo. It is normal for the abs in my car to fail and quite unnormal for it to work. Cleaning the sensor is what Ive heard is the problem.

 

[pax]

Y2Kjackal,
False ABS activation at low speed is caused by rust build up underneath the front ABS sensor. Remove the sensor and clean the area will fix it.
The sensor is just behind the brake rotor splash shield, secured by one hex bolt, there is an O ring on the sensor body, it is on very tight, lots of Liquid Wrench and gently twist and pull. The sensor is all plastic, you have to be careful removing it.
Remove, brake pad, caliper, caliper bracket, splash shield and one hex bolt to take the ABS sensor out of the wheel hub assembly.

 

[y2kjackal]

Y2Kjackal,
False ABS activation at low speed is caused by rust build up underneath the front ABS sensor. Remove the sensor and clean the area will fix it.
The sensor is just behind the brake rotor splash shield, secured by one hex bolt, there is an O ring on the sensor body, it is on very tight, lots of Liquid Wrench and gently twist and pull. The sensor is all plastic, you have to be careful removing it.
Remove, brake pad, caliper, caliper bracket, splash shield and one hex bolt to take the ABS sensor out of the wheel hub assembly.

Thanks PAX, might you know a suitable place or a part number for the O-Ring? With my luck, I just know the ring will be toast if I try to remove the sensor.

 

[pax]

No, I don't know. Once you got it out, you should be able to match it, I guess.
Don't worry too much about breaking the O ring. Mine is also 95, both front sensors came out ok, same on my 97 Astro AWD van. Both trucks had the same sympton and fixed after I cleaned the area underneath.
Just soak it with plenty of penetrating oil before you start twisting it a little, it should come out in one piece.
Good luck.

 

[y2kjackal]

Well, it took all day to just get the drivers side rotor off. I cannot believe that it would wobble but not come off. The rotor is bad and has worn a groove in the bottom of the brakes on the inboard side. From the looks of it, had to do with rust. I have seen this before in a Saturn I owned where for some reason the rotor did not get wiped or some such thing causing a portion to rust away (not surface kind of rust). I had to use much persuasion (aka hammer) on the hub and rotor (I already had a replacement) to get it off the hub. I've never seen such a difficult rotor to get off once it was able to rock back and forth.

Because I had to hammer so much and the fact that my XLT has 98k on the ODO. My question is should I go all the way and replace the rotor? It's pricey, but I don't know what if any damage I might have done.
Feedback? Cheap place to purchase one? Local parts stores want ~$200 each. Would this be something I need to do in pairs? I haven't mustered the strength or ambition for passenger side. Maybe next week.

 

[pax]

$200.00 US a piece, are they made out of gold or something? I used the NAPA rotor $43.00CAN, it's like may be $35.00US or less. All my cars and truck are using these cheap rotors for years, I don't have problem with them.
Since they are so cheap, I always replace them in pairs.
You can check the NAPA prices on line

 

[maypo59]

$200 seems awfull steep... I just did all four on my '99 AWD, and it was $158 four all four rotors.

 

[lapad96]

ABS sensor

I had a same problem on my 96 Exp with sensors. I pull them out to find one of them broken in half (plastic housing). I clean them both and carefully slide in broken one. And it is working fine for now. No moer ABS activation when I apply brakes.
I would buy a new sensor, but here in Canada Ford charges $200 for each, and they recommend to replace both sensors at the same time. That is $400, little bit steep for such a small part.

 

[y2kjackal]

Big OOPS!

I said rotors when I meant hubs. It is the hubs for $200 each, I'd never buy a rotor for that money. Just curious if I should change them (hubs) since I was banging so hard to loosen the rotor. Even loose, the rotor did not want to come out. Wire wheeled the hub and lubed with grease, penetrating oil just would not come off without some serious hammering and swearing. That being said, would it be wise to replace the hubs? I only did the drivers side so far and have not put it back together, yet. Just need hub answer.

lapad96,
I think that is for the hub, like my issue. I thought my searches showed the sensors for around 60 - 70 US dollars.

Good news was I almost easily removed the ABS sensor. It had gunk and grease, but no rust. I cleaned it up and am waiting an answer to the 200 dollar question. I anticipate the same issue with the passenger side this weekend.

 

[lapad96]

y2kjackal, I believe you don't need new hubs. Just clean the rust off and grease it with high temp. graphite anti-seize grease where it meets rotor surface. Make sure you don't grease braking surfaces. This will help to remove rotor easy in a future. All you going to need is few strikes with rubber hammer at front of the rotor.
A sensor that is what they cost here in Canada at Ford, $200. Is $50-60 price at the dealer or aftermarket products? Any dealer in States that will ship parts to Canada?

 

[pax]

LAPAD96,

In Toronto, you can give Standard Auto Wrecker a call, they may have a whole steering knuckle available. ABS sensor, wheel hub, upper and lower control arm, the whole 9 yards.
They call it either the left knee or the right knee. Tell them you only need the ABS sensor and bargain for the whole thing like $100.00. I did that a few months ago, I got the whole thing for $100.00. ABS sensor was good and the hub and bearing good too.
I was using that upper and lower control arm as a practice to see how difficult it is to remove and install the ball joints.
It was fun to play with it. The whole thing weight half a ton though.