ABS issues brake pedal started fading?

Yep, this happens when the caliper slide is frozen in either the front or rear calipers, please go over this guide to help:

https://www.2carpros.com/articles/discover-why-automotive-brake-pads-wear-unevenly

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please go over these guides and get back to us.

No, this wasn't it. The pads are now new. The ones that came off aren't much thinner then the new ones, and are evenly worn. The fluid level is also the same as before I started.

The brake pedal pumps up better when the car is off. As soon as it's started, the pedal sinks to the floor. This is a symptom that I didn't think to mention with the original post.

Did you check all four wheel to see if the slides moved? Also, I bad wheel bearing hub can cause this issue as well so I would check the play in the front and rear wheels, did you bleed the ABS module? This video can show you how.

https://www.youtube.com/watch?v=nQRnKyVyMuQ


Please upload pictures or videos in your response.

The rear brakes are drum. The wheel bearings are good. I've bled the master by itself, then the master & ABS together, then each individual line/wheel, starting right rear, left rear, right front, left front. Still no brake or ABS lights (I have both available), no fault codes, nice clean brake system components, & the same pedal feel like before I ever touched any of the system.

Okay, I would engage the parking brake fully to see if the pedal gets better, and if so remove the rear brake drums for inspection.

The parking break fully engaged didn't make a difference, but I removed the rear break drums for inspection. The shoes are thick, and everything looks good and clean. I did a break bleed again (I have now gone thru about 112 ozs. of fluid, which should be a complete flush) and still at the point where I really haven't done anything. The pedal pumps up when the car isn't running, but as soon as I start the car, the pedal goes to the floor. After I shut the car off and then pump the brakes a couple of times, the pedal comes back up.

Did you bleed the ABS module with a scanner? if not this must be done to get all of the air out of the system.

I acquired a Foxwell NT630PRO, which is supposed to be specific to ABS, but it doesn't seem to work in the way that the one in your YouTube video does. It just tells you to push the pedal down as far as you can, hold, & push the OK button. It forces your foot & the pedal away from the floor, but it says nothing about opening the bleeders. Wouldn't the air in the ABS system send a fault code, or a warning light?

No it will not send a code if there is air in the system. Do you know if the scanner is opening he ABS control valves? If so you will need to people, one the press the brake pedal and someone to open the bleeders.

Well, I took the car to a mechanic, & they said I was on the right track, but I couldn't get the ABS module bled. They did a complete flush & bleed, & resolved the problem.They said it was one of the more difficult/time consuming bleeds. If I had had the right tool, & your knowledge, I believe we could have done it. Thanks so much for all of your help!

Yep, you were one step away from fixing it, but it is good to know the car is working again and you know you were on the right track. Thanks for letting us know :)