I have a 2003 Dakota SXT with 64k miles on it. Back in 2018 I noticed when it had been raining or the humidity was really high, once in a while my brake pedal would just go all the way to the floor like I busted a brake line and the truck would have problems stopping even with the brake pedal smashed to the floor when coming up to a stop but as soon as i left the stop, my brakes were working fine and would do so for weeks/months at a time and its never done it 2 times in a row. Im not sure if its even weather related but 99% of the time, the brakes work flawlessly. I took it in to get it checked out and they replaced the front pads, discs and the 2 brake lines cause they were collapsing and not letting the calibers release the discs. After that, It still does it every once in a while and its to the point i can tell by the weather when to expect it. When it does happen, I get out and look around every wheel inside and out to see if theres fluid leaking and check the lines for leaks and Im finding nothing. These no sign of leaking or dried fluid anywhere like it had been leaking at one time. My master cylinder has no leaks and im not losing any brake fluid at all and I have no brake/ABS light coming on (the light do work). Ive taken it to a couple other shops and described the problem to them and they have checked it over and cant find anything. I wish whatever it was would just go out all together so i can find and fix it. The brakes work perfect on this truck since ive owned it except for this problem that occurs randomly. Any Ideas would be appreciated. Thanks

 

2 or 4 wheel ABS? When the pedal goes to the floor, do you hear the motor-controller doing it's dance? (4 wheel abs....)

 

I went to the VIN decoder on this forum and according to it, I have "4 wheel, rear wheel Brake ABS system" as far as doing a dance...im not sure what im suppose to be hearing/feeling. When it travels to the floor while coming up to a stop, I keep pumping it and i can hear the tires squeal from locking up about 2 times a second like the ABS is trying to kick in. Hope that makes sense. Its like pedal goes to the floor and im pumping but the truck aint stopping very well and the tires are like "screetch......screetch.....screetch" but its not a total lockup of the brakes. Ive felt other ABS in other cars that 'pulsed' like 10-15 times a second like hitting a series of bumps but mine isnt doing that

 

Well, that is certainly confusing. Look under the hood. See if there is a motor-controller under the hood, or, just a dump valve on the rear brake line. (it will be down low, probably hard to see in a Dak.)

 

not sure what the motor controller looks like but ill look around online and see if i can find a pic of it...is this what ur talking about?? https://www.carparts.com/details/Dod...B&gclsrc=aw.ds

 

That's the electronic part anyway. Should be mechanical part under the hood as well. Will look like a bag o' snakes with all the brake lines running to it. The motor itself may, or may not, be obvious.

 

ill take a look...what am i looking for when i do find it???

 

If it's even there. If it is, it complicates matters some... as the system is A LOT more complicated. If you have rear ABS only, I would be real tempted to simply disable it, and call it a day. Not like it is real effective in any event. (as you have noticed. )

 

ill go look and take a pic of it if i have it....but the vin tool on here said i had 'four wheel, rear wheel abs' ...so im not sure whether i have rear wheel only...lol. its weird cause it acts like ive lost all brake pressure in the lines but by the time i get to the next stop, its back and sometimes can run for months just fine. Hard to diagnose cause its not doing it all the time or throwing any lights/codes up

 

If you can't figure it out, pay the dealer to diagnose it, but put down in writing that no repair is to be done unless you authorize it. Once they tell you what it is, fix it yourself if it's a part swap.