Just went and checked and ABS does work when moving at faster speeds. So what's the deal with overly sensitive brakes at lower speeds? I have seen I am not the only person experiencing this. Rear brakes are adjusted and fronts are new. Guessing that a dealer isn't going to share info on this issue and would rather charge me $600 to tell me nothing was wrong.

 

How are the rears??

 

They are in good shape the reason I adjusted them only. The fronts were also good but rotors when I bought the Durango seemed like they were the issue. So purchased new rotors and pads. The pads behind replaced were new but cracked. The pads were metallic and made noise like they were worn out. If there was a bit of air in the abs module could that cause this issue? Not sure how it was maintained before I got it. Clearly the person I bought it from was not a mechanic.

 

ABS should clear any air in it's system the first time it actually engages. If there is too much air, then the system will fault, and just not work at all.

Might be interesting to plug in a scanner, and see what your various wheel speed sensors are reporting at low speeds, when the system engages.....

 

My 99 durango brakes started acting up 2 years ago, sinking brake pedal so I replaced the master cylinder twice with no change. I reasoned that the 4 wheel
abs control uses accumulators to hold fluid and a leaky valve might be the issue so I put a used abs controller on and problem solved. Fast forward 2 years and same problem again another used abs and good brakes again. 3 weeks go by and now it acts like a valve is stuck open. Pedal goes to the floor and if I pump the brakes the fluid Level in the reservoir will drop and then refill when I stop pumping. Any ideas why the brake controller keeps going out?
thanks

 

Age..... When the brakes are working right, does your ABS work right as well?

 

Yes tha ABS did function properly with no warning light or codes. I just can't believe it's a master cylinder issue because of the way its acting. I'm not new to cars I've worked on cars off and on for over 40 years including some dealership and private repair shops but this one has me stumped

 

Buddy of mine has the same problem with a 77 Trans Am. So, ABS wasn't even a thing then. Changing the master cylinder twice did not solve the problem. Waiting to hear from the shop he took it to to see what the issue is.

Usually, it's a leak somewhere. If you have rear drum brakes, pull the drums, check out the wheel cylinders. If those are good, have a close look at ALL of the brake lines. On the full size trucks, the line running front to rear likes to rust out back where it runs between the frame, and gas tank. It'll leak, but, fluid won't necessarily make it to the ground right away. Makes it fun to find.

 

Yes I understand rear brakes could leak and do that but I can watch the fluid level in the reservoir drop as I pump the brakes and then the level comes back up when I release the pedal, a leak would not do that.

 

Are you losing ANY fluid?

Have a scanner that can read live data? ABS codes?