Mechanics

STUTTERING BRAKES AT LOW SPEED

2000 Ford Explorer

Brakes problem
2000 Ford Explorer 6 cyl Two Wheel Drive Automatic 138000 miles

I recently replaced the front brakes and rotors on my SUV and have found that when I come to a smooth, slow stop I feel 2-3 " thumps" or quick vibrations in the brake pedal and the steeringwheel turns to the right a bit. This does not occur every single time the car comes to a stop, something like a 1 out of 3 times it happens. When I replaced the pads they were only a hair away from grinding down to the metal. When I pushed in the caliper, I neglected to remove the cap from the brake fluid resevoir and brake fluid came gushing out. Is it possible that there is air in the brake lines? Not sure if it's warped discs since the vibration doesn't occur at every stop. What would be the easiest method to diagnose the problem?
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Mike581359
February 2, 2008.




Various thoughts on this.

Something should have been doe with the rotors, replaced or turned, the pads do not mesh up with the worn ones. I just re-did a lousy brakes job yesterday that someone just slammed pads on on. There are important details to doing a brake job right and getting good perforfance.

-Always ajust the rear shoes when doing a front brake job if there are drum brakes in back.

-Always clean the caliper bolts, slides, anti rattle clips and caliper brackets with a wire wheel or brush. coat the parts with quality lube.


http://www.2carpros.com/forum/automotive_pictures/30961_caliper_lube_12.jpg


http://www.2carpros.com/forum/automotive_pictures/30961_caliper_lubeareas_12.jpg



http://www.2carpros.com/forum/automotive_pictures/30961_caliper_lubeareasbrack_12.jpg



Also if the feeling your getting is not consistnat as you say, pay atten to the "when" it happens. A pulsation of the rotors are most common when slowing from a highway speed as the rotors warp temporarily. IF this is the case, replace them...rarley can you machine them anymore.

Thanks for your input, Paul. I replaced both pads and rotors with brand new products from Auto Zone and sort of skimped out and purchased the cheapest rotors they had, so maybe this is my problem? I made sure to clean my parts as I went along as well, so the question is could the ValueCraft rotors I put on the vehicle be the culprit? If so, could you recommend a quality replacement?

Tiny
Mike581359
Feb 2, 2008.
With the global changes in industry, do we really know what is coming from where anymore? I wouldn't put stock into buying the " best" rotors based on price or brands that carry a big tag anymore. So many companies are now manufacturing primarily in china with these type of products, that I don't know what we have regarding quality. Yeah the box looks the same thanks to marketing and buyouts.

With your situation, is the pulsation happening from high speed stops, or immediatly after. Making the association with when the problem is happening will greatly narrow this down I believe. IF the answer is yes, then replace the rotors. Again, if you didn't use the high temp caliper lube, that may be part of the problem Everything must move that is suppossed to move.
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Logical answer. I neglected to place lube behind the pad, so I'll give that a shot and let you know.

Tiny
Mike581359
Feb 3, 2008.
The lube behind the pad is is only for noise suppression. So don't get too bothered by that, the other contacts points are the biggies for operation.

I would focus on the high speed braking at this point.

I have the same problem with my brake job. My studder happens right before the truk comes to a complete stop. It doesn't matter how fast I was going or how hard I brake. But I noticed that it happens right before it comes to a complete stop. Mine is also with a 2000 explorer. We changed both the front rotors and pads.

Tiny
Adam1424
Apr 8, 2008.
So it does get worse from higher speeds Adam?

Do you feel it in the steering wheel?

IS the abs light on at all?

No, it doesn't matter the speed and I don't fel it until just before the complete stop. I don't feel it in the steering wheel, but I d feel it on the brake peddle.
I asked a mechanic about it and he said that he thinks it has something to do with the abs. I still don't have a solution on it though. I still feel it and it happens once every 8-10 stops. He also said that the brakes will work correctly, but I still don't like the feel of it because I know it's not normal. Thanks for responding to my problem.

Tiny
Adam1424
Apr 9, 2008.
Okay, sounds lke false abs-ing. They way to uncover this is to have a scanner that is capable of monitoring wheels speeds hooked up to it. This needs to be monitored as it is happening. One of the sensors are dropping out or reading a speed other than the rest of them. The scanner will show what is happening.

The computer engages the abs because it thinks it is skidding and activates the abs system.

Thank you again for your imput and response to my problem. I am going to bring it to the mechanic tomorrow and have them run that test. Hopefully it will be a cheap fix and I won't have to give away an arm and leg. Even though they are highly over rated, I would still like to keep them

Tiny
Adam1424
Apr 10, 2008.

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