brakes that don't brake
 

so I have a 98 2500 Ram with I believe all wheel anti-lock, had to repair/replace some lines, everything after ABS, I've pushed 2 quarts of fluid through the system and when I test drove, first time Applying brakes...straight to the floor like it blew a line and when I let up ABS activated. I did regain some brakes but not enough to drive with, pedal is still squishy. What am I missing? Bad master cylinder? Still got air in system? WTF!

If have heard of a lot of guys having issues bleeding a brake system and having issues. Usually its when the fluid gets drained out of the proportioning valve. When you bleed the system, make sure you start with the longest line first, then work your way to the shortest. I use the bleeder cups you can get at most auto parts stores, always having fluid over the inside tube and eliminating all the bubbles. And it does take a lot of fluid to do the whole system, recording mileage and date.

Is the brake lite on? Does it come on when you step on the brake?

The brake light did, but I have since bleed the valve out, now there just soft without any light. Guess ill just push more fluid through must be air somewhere.

There is a special way to bleed 4 wheel abs brakes. Also did you bench bleed the master cylinder? There is also a valve that can get stuck and you may have to replace. You also may have to reset the ABS valve and ABS computer.

I have seen the rubber cups in the MC tear if the pedal was full stroked while the system was being bled, when this happens you will get a sinking pedal. I usually vac bleed, and if I have to pump, just use short strokes. I do do know that some Chrysler products had a weird master cylinder that worked fine, but, if you really pressed hard on the pedal they would sink to the floor, Chrysler told me this was normal, apparently they had a bypass in them to prevent them from overpressuring, however, I don't believe they have used that system since the 80's.

Still struggling with the brakes, bled everything, master cylinder, proportioning valve, abs module, each wheel independently starting with left rear and ending with right front. Went for a test drive 25mph push on the brakes and abs pump kicks on, pedal hard as a rock but little braking affect, lights on dash didn't';t come on, go a little further same thing except light does come on when I let off brake pedal. What the F! Anybody?

Almost like your ABS system isn't working right. If ABS kicked in at 25 Ruth you barely touching the brakes, that's not normal.

Getting vacuum boost for your brakes? Is the pedal always rock hard?

ok so my latest mis-step, I eliminated the ABS, just bypassed it, bleed system, pedal is hard when truck is off and mushy when its running and now back brakes aren't releasing fir ****, time to part it out and scrap it? Yes its getting vacuum, that's probably the problem, brake pedal hard when I unplug vacuum lead and mushy when I plug back in. Only bought this truck because its the same year as my other one that just died, figured I could swap parts and make one work right, so far no luck, now I have 2, 20 year old POS sitting in my driveway and probably could have bought a running truck with the $ I'm wasting.