I had a wheel cyl leak on my 84 D150 so I replaced both wheel cylinders as they looked like originals.Bleed system and get real good pedal feel. Ah another job well done. Next day I get stuck in trafic and the pedal starts to feel mushy but not every time. A couple of days of this and the weekend comes up so I figure that when the leak happend the travel in the master cyl increased and maybe there was corosion i n there and the master is starting to blead by some. Its 25 years old so I get a reman and Bench blead the new one and install. pedal feels good so go ahead and quick blead all 4 wheels just to make sure every bit of air is out. Make sure to keep the resovors full and after I'm done go to test drive and pedal goes right to floor after a slight hesitation about half travel. Look for leaks-none. repet all the bleeding procedures and the pedal just goes to the floor. Notice that the brake lite will not go out. is it posible that the proportioning valve can stick and bleed fluid internally or is my reman master bad? and has anyone rebuilt or tore down a proportioning valve? I cant seem to find a replacement at the parts stores.

Everything is tight and no leaks. I did notice that when I had the cap off the M/C that when the pedal was pushed the fluid "blew" out the top.

Nothing else is jumping out at me. I would suggest a pair of brass inverted flare plugs to cap the M/C to check it or R&R the M/C(not a guarantee that's it but they do have a high failure rate). We can reset the prop valve light after we get this.

Yea I'm going to take the m/c back and get another.The easyest to do but i'll have to pick up more fluid too. the m/c has a llt warrenty so they will replace it.

Check the whl cyls.Make sure the pins are in place.Ive had them pop because they werent seated in the shoes.Then open a frt bleeder and have someone mash the pedal to reseat the valve.Close it and rebleed.That and make sure the rears are adjusted right.Rocky

Well I did the plug m/c and test thing and the m/c was definitly bad. I replaced it with a new one and now I have a good pedal. Unfortunatly the brake warning lite will not go out. Ive bled the brakes several times and have no air and all 4 can be made to lock up if i try. I have never ad to do anything special to reset the lite before. Its allways gone out after the problem was fixed. Is there a trick to this that I have missed?

I bought a Reman for my Dart and it was junk, so i got to do it twice