SOLVED - - No brake pedal, at wits end...
 

OK, spent the day bleeding, literally:


1) bled PR, DR, PF, DF, just straight pressure bleed using my Motive
- pedal improved, some, but not driveable at all yet


2) bled again, this time tapping the ABS block and the open caliper with a rubber mallet, using the Motive
- pedal improved more, is "firm" now but sinks about 3/4 of its travel, "firmly", before acting like a normal brake pedal


3) applied pressure to the system using Motive, ran the ABS bleed procedure, then the individual line identification procedures, got the tinniest of bubbles or two in the MC and then bled each caliper
- Now I get brakes at the top of the pedal, it is "firm" but still sinks about 3/4 of it's throw before setting into what I would call a "normal" brake pedal. The car still stops, but instead of having nothing until the last, less than an inch, of travel and then having great brakes - I know feel he brakes engage at the top of the pedal, the pedal is "firm" but depresses about 3/4 of it's total travel before it acts like a normal brake pedal and actually stops the car. And again, that last bit of travel is perfect, ABS works, doesn't pull or yank to one side and I have no codes...


Has to be air??


(EDIT) - when I say "bled" above, I literally ran two full quarts of fluid through each circuit then went back and filled the Motive and did it again, so 4 quarts of fluid through each circuit, as a reference... stumped.

Have you checked the master cylinder vacuum line? It could be collapsing.

watching this thread, hoping for a resolution for another species of car
 

Hope you resolve your brake problem, Purplefade. I've a very similar problem on a totally unrelated vehicle, an '08 Chevy Cobalt.

I've been working on it off/on for over a year (since April '20), and changed MC, inspected the booster & all hoses, power bled with a Motive unit, new pads & rotors, adjusted & bled all (four times), and used my Foxwell to bleed the ABS. There are brakes...but the pedal likes to go to the floor instead of holding pressure, so my wife won't drive it (but I can, if absolutely neccessary, since I had a '69 C-10 that did the same), and I've given up workingonit.

I had a neighbor helping me with the adjusting & bleeding of brakes (I have a bad back, knees, & left arm), while I did the rest ... installation of front pads & rotors, master cylinder replacement, Motive power bleed, and Foxwell ABS procedure (done three times). but we haven't touched it again in several months now. I won't ask him to help anymore, as it is probably going to wreck his back, too!

So if you find a solution, one I haven't tried already, I might just be able to fix that car, too. If not, I'll find a local shop to do it, for $$$.

My wife is so rough on cars, I need to put the Cobalt back into rotation with her '98 GMC pickup (needs tires) and my old '09 HHR Panel (just had to do pads & rotors she damaged... she stomps on the pedal, and I really need to put on new front struts...she never met a pothole she didn't like). I'll never let her drive the '01 X5 or my '04 2500HD, since she'd destroy them, too!

I GOT IT!!


Pedal is back to 90% of what it was and I think driving it, letting any air left in the system move around, and re-bleeding them again this coming weekend that I'll be 100%.


So, I spent Saturday bleeding brakes:
1) Motive pressure bleeder, ran two courts through, closed system, refilled, ran two more quarts through and then closed that caliper and moved to the next - 4 quarts in total through EACH caliper. - Pedal improved, but was still active only at the bottom.


2) Motive pressure bleeder, same process, but this time I cycled the ABS pump - Pedal improved more and it started to engage about midway down.


3) Motive pressure bleeder, same process, but this time I isolated each line and ran the ABS valve for only that caliper. - Pedal starts to engage almost right at the top of the stroke and increases in stopping force as you press down, bringing me to a very nice stop. (Pedal still isn't 100%, but it's darn close, I'm sure still air, because of the massive increase in pedal since bleed 1.)


In total I spent about 12 hours bleeding brakes, but my motivation was that I continued to see micro bubbles in the front circuit, far and few between, but pretty routinly, to the point my wife thought I was crazy, seeing things and making it up - so she verified and I wasn't crazy.


I ran fluid through the front until I was almost satisfied with the results and buttoned up, and I'll be darned if my rewards wasn't a very nice pedal! Started it, great pedal, shut it off and restarted it, great pedal, took it our and around my local round-about loops and, great pedal - so I moved on to the freeway and have since been driving it, pretty much all day, with a great pedal :2thumbs:


I'll be darned, I really thought it had to be something more "sever" than just bleeding, keep in mind I had two trustworthy guys that I know personally attempt it with no better results... I guess "hard work does payoff"!

I think the only way to bleed these cars after opening the system is use a pressure bleeder AND run the ABS Bleed procedure with INPA or some other 2nd level scanner.

for a simple brake fluid flush, you can get by with just a pressure bleeder, but anything more you have to activate the ABS bleed routine with a scanner.

congratulations, I hope
 

We tried a combination of pressure bleeding with ABS bleeding (via Foxwell), drip bleeding with Foxwell, and using vacuum at the bleeders, again with the Foxwell ABS bleeding program. Couldn't tell much difference between the three methods.

My Motive Power unit wasn't as good as I thought it should be, since I could never get over 8-10 psi (I had a different brand years back that'd give twice that). Drip method (just adding to the MC as it was needed) was useless while the ABS program was running, and the Pittsburg (Harbor Freight) vacuum bleeder drew lotsa bubbles out, but never clear fluid on the last bleeder.

I hope a professional shop will have the right equipment, the personnel needed, and the honesty to fix it cheaply, without firing a parts cannon at it. But my wife says "get 'r done" regardless. Oh well.

What a journey! I hope that resolves it for you OP.

Thanks for sharing the solution here so it can help others!

There are two distinct bleed procedures you need to do with the scanner. I only saw the one mentioned.

can you expand on that?
 

I'm interested in the two procedures you mentioned, whether only for future use on my X5, or if two might also be included in the GM programming in my Foxwell. I didn't see any options.

I have a 2005 mini r53. It had a rusted thru rear brake line - I replaced it, and the Master. I used the motive pressure bleeder, and I had the car running when I bled. The rears were uneventful, but the left front caliper blew an amazing amount of air from the bleed valve. Pedal feel after that has been fine.