Hi,

Since a few weeks I feel the ABS working sometimes when it should not during braking. I feel a shaking pedal and hear a knocking sound. It happens every now and then, but it happens more often lately. The brakes work well.

I heard it might be a bad connection in the ABS wiring, or dirt beneath the sensors. Do you have any advice how to solve this?

O, almost forgot: it's about a 2001 Tribute 2 liter.

Regards,

Bert

 

You know, your vehicle is 13 years old. it would probably not hurt If you take the brakes apart, clean all the parts and put them back together. It is also a good practice to flush the brake fluid every 3 years or so. Has it ever been done?

The ABS kicks in when the wheels go at different speeds. If your brakes work unevenly one wheel will slow down more than the others. That is enough to trigger the ABS. Corrosion on the sliders, dirt and grime can contribute to this.

 

I guest you are right. The vehicle is so reliable so far that maintenance is reduced to engineoil, gearbox oil, filter and belt changes.
The last five years at least I use the same brake fluid. I will schedule a day for brake maintenance: renew brake, fluid and disassemble and clean the brakes.

Thanks for reminding,

Bert

 

Another possibility is tires. Believe it or not, my 3 HB, and its ABS, acted REALLY strange after I installed some Kumho AXS tires. That was a failed experiment, however if your tires are worn, or if you've just replaced them with new, that too could be the problem.
First guess though would be dirt in the tone ring that's read by the ABS sensor. Easy fix if that's the problem. Pull the wheels and locate the sensor. The tone ring(s) will be just below them on the spinning part of the axle bearing or behind the brake rotors. All you need do is clean them with a stiff non-metallic brush. Soap and water helps get the worst of it out as well.

 

Good advise. He will take the wheels off anyway when doing the brake service.

Yet another cause for ABS issues is worn wheel bearings.

 

I've had two escapes/tributes have issues with cracked ABS tone wheels on the CV joints.

 

As soon as I serviced the brake system, I will let you know if there is anything broken, and if cleaning solves the issue. No worn nor recently replaced tires by the way.

Bert

 

Changed oil in the brake system and inspected the brakes. Not much dirt, but two broken abs rings on the front wheels. After replacement of the rings (needed heating them to get them on the axels), the brakes work fine again.

Bert

 

Thanks for the feed back!
i did not expect that the tone rings would brake. They must be cheap castings.

 

Bingo, I win.