Chrysler Repair: 1987 Dakota brake query.

Question
Hello again Roland, I have a 1987 Dodge Dakota 3.9L, 4 wheel, Auto, 160,000 miles. My front brakes have 25000 on them put on 5 years ago as well as lines, hoses, rotors, calipers etc. Rear brakes have 400-600 miles and are totally new. Weight proportoining valve was broken and parts missing so I blocked secondary line at meter and bypassed using primary line only. 75 miles away today after several miles of a shake seeming to come from the front right I had to slow to use exit ramp. Upon braking I lost some pedal and brake light went on. Stopping on shoulder I saw no leaks and continued. Shake seem to get worse until I would hit a bump and the whole thing would settle down for a few miles. Then it would shake again even if I didn't touch the brakes, no speed outside of a walk seemed comfortable. Turning around as I had 180 miles to go I got on a back road and near home and used them harder and car pulled to right. My question is: is caliper on left front sticking or is my master cylinder which was replaced also around 5-6 years ago gone bad, as my right rear brake seemed hot-smelly hot- when I got home. Visual inspection on front brakes show everything ok. Perhaps left rotor has a high spot. Fluid level correct. Should I go for a new master or replace calipers and rotors up front?

Answer
Hi Wolfgang,
I don't have manuals for trucks of the 80-90's so can't give you any advice that would be  
"expert". However, modifying the system by removing the weight proportioning valve and by-passing the lines could have caused your situation. Try correcting that and then consider the other possibilities.
Roland