Does it have abs on the front or rear? Had a similar issue with a late model Jeep. Air was getting stuck in the ABS module. Fought it for a long time before I finally got it figured out. Also had a 97 dakota, which I imagine is similar to your 99 Durango, but it didnt give me any fits when bleeding brakes. Besides the dumb @$$ combo of metric bubble flare AND standard brake fittings on the same truck
