I have been working on my 95 jeep wrangler's brakes and have replaced the proportining valve, replaced all of the brake lines thru out the vehicle. After bleeding it works fine till the first hard stop (ie: quick red light) then the front disc brakes drag very badly while the rear drums seems to be fine. I have chked the vacum at the booster, its fine, I see no leaks at master cylinder or any other fitting or line. Does this sound like a failing master cylinder? I ask cause I hate to keep throwing money around, but I guess its good to have a all new braking system. Thanks alot, hard working DIY guy
That could be a number of things that you are going to have to find through process of elimination. Get them into the stuck position and get the front wheels off the ground so you know when they free up. Start by cracking the line at the master and see if that releases them. If not, try it at the bleeder. If still no, n then you may have bound up calipers or slides.
July, 30, 2011 AT 4:46 PM
After replacing the master cylinder it worked fine for 10 miles and many hard stops trying to get them to drag, I figured it was good, started off toward the beach, and they completely locked up, 2nd gear didnt have the torque to push it down the road. Went to the local auto part store and got new Calipers, when replacing I had noticed alot of built up dirt and dust. I would have never imagained that both front brakes calipers would lock up at the same time, repeatedly 10+ times in a row after bleeding. I did complete my trip, 200 miles later, not a bit of trouble. Damn 50 bucks in calipers made me completely overhaul my brakes as I was looking for the common bond with the 2 front brakes (i wanted it to be the porportining valve). Live and Learn, remove swamp muck from calipers!
July, 30, 2011 AT 5:01 PM
That's why I gave you a method to isolate the problem. Glad you found it in the end.