HEY--i have a 2000 durango 4x4 slt--the brakes go about to the floor and will hardly stop you--at one time a few years back,they would lock up at times and slide you,but now they have just got to the point that they go about to the floor and wont hardly stop--i changed all pads a year or 2 ago and bled everything with no help----now it doesnt get drove much but now the brake and abs light are also starting to come on and off on occassions--so i just went and changed the mastercylinder(fluid was black) and i refilled with new fluid and bled all four wheels a good bit to get most of the bad fluid --but i didnt completley flush it until it was all clear---and bled the master cylinder----ok now i still have the same problem---this didnt fix anything--it feels as if the brake is getting tight when i bleed it,but as soon as you drive it ,it goes about to the floor and feels like it wont hardly start----any help would be appreciated----thanks

 

ok--brakes seem alittle better since i changed the master cylinder but are still spongy like and go way down before they actually brake--im thinking that it may also need a booster and maybe that the lights are just coming on because it may need the sensor in the rear differential--but not sure---the lights are off at first and then always come on when the first good stop is made ---any suggestions???----thanks

 

The booster might have something to do with it but it's very strange because thats just there to help you brake. The fact that it sounds like it's in the braking system and not the booster you might need to replace the ABS module and I think I've seen them rebuilt on www.ebay.com for like $60. Anyways with black fluid and the replacement of the Master Cylinder thats where I would have pointed you.

If you know that everything is working right from the petal to the master then it's gotta be down stream. Black is usually caused from deteriorating seals. There's lots in the ABS valves in the braking system right below the master cylinder.

Take it to a shop and get that thing flushed.

What about the proportioning valve.

Here is a picture of it and how to get to it:
https://dodgeforum.com/forum/1st-gen-...-and-5-2l.html

 

IM thinking now that i may of not got all of the air out of the mastercylinder---i put it on and then filled it up and purged it---im just wondering if i need to pull it and purge it on the bench and then put it back on and purge the lines of ALL of the black fluid?---thanks for the reply

 

Definitely make sure all of the air is out of the lines.

 

Should have filled it on the bench then installed. I think theres air and your right. Take it in and have the entire system flushed by a good shop.

Also if the wrong oil is used it can deteriorate the seals inside which may have lead to your issues. Make sure you check your owners manual for the correct fluid and ONLY use that.