Hello friends, I am writing this forum because recently my 2004 Ford ranger 3.0 L, 4x2 got super spongy/soft brakes out of nowhere but it only happens when I turn the car on. I was reversing out of my parking lot and heard a crack and that’s when the brakes got super spongy. I brought it to my mechanic and we changed my whole breaking system from calipers pads rotors. Just everything you can think of for the front. we also put in a new master cylinder and a new booster. (All of these parts were brand new) we also put in new wheel cylinders on the rears. There is no leaks on any of the lines we tried bleeding 1 million times, and nothing worked. At this point, we assumed we had a faulty ABS. we couldn’t find any for sale so we went to the junkyard and got two of the same ones. The results were still negative with those. But they also come from a junkyard, so they are not so reliable. at this point, we have tried everything under the sun to fix the spongy break issue. Does anybody have a clue what this can be? And no the car is not drivable at all. There is not one bit of pressure on the brakes.

 

Spongy brakes means there is air inside the system somewhere

Hydraulic fluid(brake fluid) can't be compress easily but air can
When you press on the brake pedal the force applied at the Master is transferred to each caliper and slave, applying the brakes, if there is any air in the system then the force is used to compress the air and not apply the brakes, so a spongy feel

Yes, the 4wheel ABS units can have air inside, there is a device that can be hooked up to bleed the air out of these, its electric and opens and closes the valves inside to manually bleed any air out
Mechanic should know this

 

I can agree that we did not try to bleed it with the scanner tool. We should probably give that a shot. But what are the odds that three different ABS units have air in them? we tried different units and had the same result with all of them after breeding the breaks 1 million times. Does having the ABS unit unhooked up.( meaning, no lines connected to it.) let air get into the system?

 

4WABS units have all their brake lines on the top for a reason, its so you can disconnect and/or replace lines without any air getting in
Anytime you disconnect an ABS unit and turn it on it's side fluid will come out and air comes in
If Master reservoir ever ran dry or master to 4WABS lines leaked then air was injected into 4WABS unit

Did you ever find out what made the "Crack" sound?

Is the firewall mounting for the booster intact it didn't break, or the brake pedal assembly
These are long shots but a "crack" noise is not that common when referenced with brakes
An ABS valve "might make a noise" if it failed, also a longshot

 

Also, one other thing, I believe it’s a rear wheel ABS but I may be wrong. So do you recommend I try to bleed the ABS electronically with the scanner before I buy a third ABS? I found one off eBay that’s apparently refurbished and going for $250. I got two from the junkyard and they’re all giving me the squishy brake symptom. I’ll go ahead and try with the scanner before I order that other ABS. Also forgot to mention that I’m thinking that cracking sound had something to do with my front caliper/pad because right after that cracking sound, my front wheel was covered in brake fluid and that’s when the squishy break feeling started happening right after that happened I had absolutely zero pressure on my brakes . and by the way, this is how my pad looked. can this possibly be why why my ABS got Air in the first place? The pad that you see below fell out my caliper while I was parking my car without even taking the wheel off. and I had to take the other one out which was in bad condition too. I’m pretty new to this I’m 16 years old and this is my first car so sorry if I sound kind of stupid. The second picture is what my wheel looked like after I heard that crack sound it’s covered in brake fluid! Anyways, I replaced my whole brake system and now we’ve got no leaks just a squishy pedal. Also forgot to mention that my parking brake light is stuck on. It was never like that before , it only came on as soon as I heard that crack sound and that fluid spill everywhere. I still can’t get it to go. My mechanic thinks it’s the sensor, but I doubt it would be the sensor?

 

The caliper seized on that wheel, which causes excessive pad wear, assuming the other front wheels pads were in better shape
Vehicle should have started pulling to the left a bit when that side's caliper seized

If that happened at the same time as the noise then that might have caused the "crack" noise

Yes, first thing would be to bleed the 4WABS unit, usually have to do that with a brand new one unless it specifically says its "pre-bleed", AND its shipped with plugs sealing the 5 brake lines ports

Once the Master and 4WABS unit are bleed, its easy to bleed the wheels

With foot off the brake pedal there is a straight shot from master's reservoir to each wheel, no valves or anything else blocking the flow
So if you open a bleeder at any wheel GRAVITY will cause the brake fluid to flow DOWNHILL from reservoir to that wheel, you can catch it in a bottle and close bleeder, then put it back in the master reservoir
Gravity bleeding takes some time but also tells you it a line is blocked, no flow or very slow flow partially blocked


Why can't 4WABS unit gravity bleed?
Because it has passages that can trap air inside but still allow fluid thru, and when you apply the brakes that air will be compressed so limited/squishy braking