My 4-wheel ABS 99 Durango 5,9 engage the ABS system when slowing down for a stop. No warning lights lit, but I can feel pulsing through the brake pedal and hear the ABS pump's intense working. It happens a few times a ride. The pump will continue working for 5-6 seconds after release of the pedal, no matter if I take it to a full stop or accelerate on again. It only occurs in speeds less than ca. 30 mph, both at slightly pressed pedal and with a lot press.

Any idea what to look for, where to search? Car has 90k miles on it. The ABS pump (or brain - can't remember) was renewed at 55k miles in 2006 by previous owner. No servicing on brakes later, except a new Mopar rear wheel speed sensor last summer as the ABS and brake failure lamp lit.

 

Assuming the ABS pump is fine, have the rear brakes reviewed, replaced or at least adjusted PROFESSIONALLY.

Cheapest fix, easiest first place to start and likely the culprit.

IndyDurango

 

I would also check the tone ring. It may be full of crud and can cause the ABS to falsely sense a skid.

 

Thanks for your replies. Are the tone rings accesible for inspection/ cleaning without removing the wheels? I guess they're only at the front axle (why the rear axle has a single sensor atop of it)?

If tone rings are ok, I guess I'll pull the rear drums for inspection. The first year or so I had it, there were some slight squeeling from the rear brakes. As if the shoes were minimal dragging. The previous owner didn't drive much so maybe they just needed some regular use to be fit again. The noise ceased after some time so I didn't pay more attention at that time.

I am also asked to check out potential vacuum leak into the brake booster. I recently seafoamed the engine via that hose so I better check that everything is hooked up and intact.

I forgot to mention in original post, but two years ago all the brake linings were renewed and of course the fluid.

 

It's rear ABS on your D only. 98-00 is rear only. 01-03 is 4 wheel IIRC.

 

i was under the impression that 2wheel was standard on all trucks and 4wheel was an additional charge to get it. at least for 01-03 that is the case

 

4 wheel abs was an option on all years. My 99 FSM talks about the 4 wheel system.

 

I know nothing about the tone ring. I sorta thought that was a 4.7 thing.

Assuming all else is good, still say (from personal experience) that the rears need adjusted/replaced.

IndyDurango

 

Indy: a tone ring is just a generic term for a device used to measuer angular speed of something, the 4.7 has one used by the PCM to measure speed and where the engine is in its stroke to control timing, however the rear differential also has one in it which is used to measure the tires RPMs, which is then converted to MPH for the speedometer readout.

 

Thanks for the education ss!

IndyD