Learn me brakes (mkii Focus edition)

After seeing the E21 thread down the page, I realized that I am not the only one having brake trouble. Rather than clutter up his thread, I thought I'd make a new one.

The vehicle in question is a 2009 Ford Focus Sedan SE with ABS and ESC/traction control (AdvanceTrac®). Front discs, rear drums.

The short version is that my pedal feel suddenly went bad. Occasionally it will be good for a couple of weeks, but I have not figured out exactly what I need to do to keep it good.
I drive this car every day. I know exactly how far I push the pedal to stop. When it's acting up, I push the pedal, I hear the front brakes start to engage, but then nothing happens. The car keeps rolling. I push further and further, and as I approach the bottom, the brakes finally grip and the car stops. One easy way for me to tell if the pedal is bad is if I can slide my foot onto the gas without lifting my foot. If I can, great. If I cannot, then the pedal is too low. I know, I know, this is terribly inaccurate, but it's the best I can do without a tape measure and a camera facing my feet while driving. Pumping the pedal 2-3x will firm it up for one stop.

The best way to organize my thoughts seems to be a timeline, so here goes:

Legend: 
Good, Normal, Regular pedal: Pedal engages when expected. When stopped normally, my foot can slide onto the gas pedal without lifting my foot.
Bad pedal: Pedal engages late. When stopped normally, my foot bumps into the gas pedal if I try to slide it off.

1.  Car is driving normally
2.  ABS activation (aka I slammed on the brakes). Pedal immediately felt bad.
3.  Less than a week later, the pedal goes back to normal.
4.  Two days later, another ABS activation. Bad pedal.
5.  I replaced my front pads+rotors, because they were due anyway. I bled all four brakes using an assistant. Bad pedal.
6.  I purchased a Motive and bleed it with that. Bad pedal.
7.  I disassembled the driver side drum. I prepared to replace the shoes, but they measured the same as the new ones, so I didn't. I made sure the self-adjuster worked by pressing the pedal while the drum was off. I heard clicking and then the drum did not fit over the shoes. I reset the adjuster and was able to put the drum back on. I pushed the brakes after reassembling and heard a couple of clicks. The drum scraped the pads, just a little bit. I backed the car out of the garage, still bad pedal. 
8.  The next morning when I drove to work, the pedal was good!
9.  Three weeks later, I lost traction on the front wheels (ESC engagement?) when trying to start moving on slick pavement. I immediately had a bad pedal. I stopped the car at the light, my pedal was fine, spun my wheels, drove to the next light and it was bad. No ABS engagement, nothing. Maybe traction control?
10.  I took it to a shop for a "free brake inspection". The tech noticed the bad pedal and suggested a bleed. Since I didn't trust myself, I let him bleed it. Still bad pedal. (side note, he refused to take apart the drums without replacement, as they are "sealed").
11.  I disassembled both drums, cleaned them with brake cleaner and tested the self-adjuster as before. Bad pedal.
12.  I made this post. The car is sitting in the parking lot. Maybe it will be good when I drive home? 

Other research I've done suggests that the master cylinder, the ABS module, the rubber brake hoses, the bleeder valves, the brake booster, the pads, rotors, shoes, drums or the drum adjustment could be at fault. That makes me think that nobody knows what they are talking about.

Going through that list:

•  master cylinder: Have not tested, most likely culprit at this point.
•  ABS module: not sure how to test. I've read that it should have no affect on normal braking.
•  rubber brake hoses: No leaks, and the difference is too sudden and great for that to be it.
•  bleeder valves: No leaks.
•  brake booster: Probably not it bas on the fact that the pedal is soft, not too hard. But I haven't done anything else to rule it out.
•  pads, rotors: No change after replacement.
•  shoes, drums: Old shoes are the same thickness as the new shoes, even wear. No ridge on the drums.
•  drum adjustment: I was really banking on this being it, since it made perfect sense in my head. If the rears need more pressure to activate, that would cause exactly what I was seeing with the fronts engaging slightly at first, and pumping the pedal fixing it. This came crashing down when I found that there is no external adjustment on these drums. Taking them apart and resetting the adjustment (so the next press of the pedal will engage the self-adjuster) is all I can do. I did see that they sell drum shoe hardware kits, so maybe there something in the springs that isn't doing its job.

I'm hesitant to crack open the master cylinder due to my poor experience with bleeding (though I suppose I'll figure it out one day). The broken seal thing makes sense as far as the soft pedal goes, but I can't see how pumping would fix that. If it's bypassing fluid once, I'd figure it would do it each time, regardless of pumps.

My next steps appear to be one of: master cylinder, drum shoe hardware or the ABS module.

Well, that's my story. Thanks for reading. Please let me know if you have any tips :)

You can rule out the rear adjusters. All they do is compensate for shoe wear. They probably click once every 10k miles. The fact it happened after ABS activation points to the ABS module, BUT, have you carefully checked the wheel bearings?  Bad wheel bearings knock the pads back to produce a low pedal. Also a master cylinder failure is usually consistent, but not always, and it is cheap, so if the wheel bearings are good do it next. 

I vote for bad Master cylinder. 

How's fluid level? Fluid color? 

I also vote master cylinder is failing.  ABS has a million different diagnostic self-checks that are constantly monitoring system health.  It would turn on the yellow ABS warning light, and probably the red BRAKE light too, if there were a fault allowing internal fluid accumulator to fill during non-ABS operation.

TurnerX19 said:

You can rule out the rear adjusters. All they do is compensate for shoe wear. They probably click once every 10k miles. The fact it happened after ABS activation points to the ABS module, BUT, have you carefully checked the wheel bearings?  Bad wheel bearings knock the pads back to produce a low pedal. Also a master cylinder failure is usually consistent, but not always, and it is cheap, so if the wheel bearings are good do it next. 

Thanks for the adjuster tip. That makes me feel better. I kept thinking that I was doing it wrong. I have not checked the wheel bearings carefully, but I can definitely do that shortly. 1 vote for MC so far.

John Welsh said:

I vote for bad Master cylinder. 

How's fluid level? Fluid color? 

2 votes for MC. Fluid level is consistent and is extremely clean (now). It was pretty dirty when I started this whole mess, but is has been thoroughly flushed now.

AngryCorvair said:

I also vote master cylinder is failing.  ABS has a million different diagnostic self-checks that are constantly monitoring system health.  It would turn on the yellow ABS warning light, and probably the red BRAKE light too, if there were a fault allowing internal fluid accumulator to fill during non-ABS operation.

3 votes for MC. Now on order from Walmart (Motorcraft). That's a good point about the ABS light/self checks. The light is definitely off, and does come on during the start up check.

I'll check the wheel bearings now, but otherwise will report back after the MC swap. I should be able to get that done this weekend. Thanks for the advice!

Im betting ABS system has air in it. It will not set an ABS light or a brake light in the dash if its just air trapped. This happens ALL the time with the Focus/Fiesta. Every time you get a bad pedal, whether or not its the ABS or AdvanceTrac/traction control goes back to the ABS HCU/ECU.

You may need to try a service bleed using an IDS with a pressure bleeder. Sometimes its the only way to get all the air out of those things, especially if it has the abs lines coming out the top of the HCU.

kevinatfms said:

Im betting ABS system has air in it. It will not set an ABS light or a brake light in the dash if its just air trapped. This happens ALL the time with the Focus/Fiesta. Every time you get a bad pedal, whether or not its the ABS or AdvanceTrac/traction control goes back to the ABS HCU/ECU.

You may need to try a service bleed using an IDS with a pressure bleeder. Sometimes its the only way to get all the air out of those things, especially if it has the abs lines coming out the top of the HCU.

i got $5 says that isn't it.   let me know who i'm betting and i'll let you know where to send your $5.

:-)

that's a good-natured poke, of course, but where would that air have come from in the scenario described by OP?

I am leaning towards ABS HCU. I know this is a Focus and not a Fusion, but the symptoms are exactly what we had on my sons 2008 Fusion. No ABS light was present when the issue was present. It was always triggered by an ABS activation and initially would go away. Eventually it remained with a soft pedal and I replaced the HCU with a junkyard unit a couple of years ago. The Ford investigation has been going on for quite some time.

https://www.carcomplaints.com/Ford/Fusion/2008/investigations/

That is why I bought the MC from Walmart. Free returns :)

I've read about the air trapped in the ABS issue. One suggestion included going to a gravel lot and slamming on the brakes. I personally don't have such a gravel lot, so I'm not going to do that. It primarily showed up in reference to the Fusion, which is odd to me as there have been for more Foci sold than Fusions. Quick edit: I was wrong. During the years between 2008-2011, 704k Foci vs 795k Fusions. Not a huge difference, but past 2011 the Fusions consistently sold about 50k more per year.

I asked the mechanic specifically if they could could get the air out of the ABS and I was told yes. I'm inclined to think that we were not on the same page. I probably should have went to the dealer in the first place... am I correct in assuming that IDS is something that only the dealer has access to?

In parallel I will start looking to see which Pick n' Pulls have Foci.

AngryCorvair said:

kevinatfms said:

Im betting ABS system has air in it. It will not set an ABS light or a brake light in the dash if its just air trapped. This happens ALL the time with the Focus/Fiesta. Every time you get a bad pedal, whether or not its the ABS or AdvanceTrac/traction control goes back to the ABS HCU/ECU.

You may need to try a service bleed using an IDS with a pressure bleeder. Sometimes its the only way to get all the air out of those things, especially if it has the abs lines coming out the top of the HCU.

i got $5 says that isn't it.   let me know who i'm betting and i'll let you know where to send your $5.

:-)

that's a good-natured poke, of course, but where would that air have come from in the scenario described by OP?

OP bleeding the brakes and the "technician" bleeding the brakes. See item #5 on his list of things he did beforehand. The initial issue when he activated the ABS during a panic stop could be a start of something wrong with the HCU per his items on 1-4. After he flushed the brakes it is certainly possible for air to be in the lines causing the pedal getting worse and worse after each person worked on it. Then technician at shop bleeds it also and introduces more air into the system causing a bad pedal from there on out.

And not to poke fun at the OP but he even states in his long read that he isnt the greatest at bleeding a brake system. I cant count on one hand how many people ive had to correct on how to not introduce air into their brake system whether it be from up top at the MC or at the bleeder valve at the caliper/wheel cylinder.

So HCU going bad plus air in the lines? Explain your side of things thinking its the master cylinder. Im genuinely intrigued.

When replacing the HCU, if I go that route, is there any bleeding procedure I need to do before or after installing it? Alternatively, is there a way to bench bleed my old one after I take it out?

Or is the only way to do this to interface with the HCU via an IDS system?

In reply to ValourUnbound :

I did not bench bleed the HCU.

I was able to use the Autel unit at this link to auto-bleed the HCU system on the 2008 Fusion. 

https://www.amazon.com/Autel-MaxiCheck-Scanner-Diagnostic-Service/dp/B07P621KR1

In reply to kevinatfms :

Classic symptom of MC going bad is “pumping the pedal makes it feel good for one stop.”

Failure Mode is MC seal is marginal.  On slow applies it allows fluid past the seal and pedal travels farther than expected.  Quick pumps apply force more quickly to the seals, forcing them against the bore wall more securely and thereby “pumping up” to provide more normal pedal feel.

i suggest this because pedal feel went bad before the system was ever opened up.  

Oh man, the tension. Is it the MC? Is it the HCU? Find out next Monday, aka the work day after my MC and scantool come in.

Is there a way to verify that the MC seals are bad once it is out of the car? Or would I not be able to tell on a bench due to different lever arms, no booster, etc.

In reply to ValourUnbound :

I can't come up with a good way to bench test it as without the mechanical advantage and boost as you mentioned it will be difficult to simulate the forces needed to see if it bleeds fluid past the seals over time.

I'm just spit-balling here, but it seems like if the MC is the issue you could apply the brake while running but stationary  with a high force for an extended period of time and see if the pedal creeps downward once it seems to stabilize on the initial actuation. If fluid is getting past the seal initially, it seems like it would continue to bleed past the seal. For what it's worth, I think I am wrong more often than I am right :)

It isn't going to be air in the system.  Where does the air go on the applications where the pedal feels good?

Start the car.  Put your foot on the brake pedal with the effort you would use for a gentle stop.  Maintain that pressure.  Is the pedal dropping over 30 seconds?  MC.  

A) Master cylinder.  Do the leak down test. Just rest your foot on the pedal for a minute.  If its sinking the master cylinder has an internal leak.  This may not be your only problem but changing it would at least eliminate one.

B) I don't know if this is true from personal experience but I have read that sometimes ABS systems need to be bled backwards with a power bleeder to get all the air out of the system.

  But I am not seeing in what I am reading how air could have gotten into the system in the first place.

Streetwiseguy said:

Start the car.  Put your foot on the brake pedal with the effort you would use for a gentle stop.  Maintain that pressure.  Is the pedal dropping over 30 seconds?  MC.  

jharry3 said:

A) Master cylinder.  Do the leak down test. Just rest your foot on the pedal for a minute.  If its sinking the master cylinder has an internal leak.  This may not be your only problem but changing it would at least eliminate one.

The pedal is on the floor with any pressure. Nowhere to drop to! Though the car does stop, so maybe there is a small amount of travel remaining. The last thing I want to do right now is force the pedal too far.

My approach this weekend will be to swap the MC and see if that helps. If it doesn't... swap it back and return it? I'd feel bad, but it's Walmart. I've been needing a OBD2 scanner for a while anyway, so I see this as an excuse to buy one. If it doesn't fix my problem, that's fine. Hopefully one of these things does :)

Bad news, guys.

I was driving home  today (probably the 6th time I've driven the car today), when all of a sudden the pedal started working as expected.

Do I change the MC out now that I have all the parts or wait for it to go bad again? I'm always hesitant to mess with things that are "working".

Change it now please.

Alright, here's an update.

I did not die in a brake-induced accident.

I have done the following:

1. Replaced master cylinder (after bench bleeding).
2. Bled the system using the Motive.
3. Used a scantool to cycle the ABS.

I have done all three of these things multiple times. I am as sure as I can be that there is no air in the system (I wouldn't bet my firstborn, but maybe my second or third).

The pedal feels exactly the same as before, falling beneath the gas pedal before stopping. Unless I have mastered wizardry and managed to break my new MC in exactly the same way as the original, something else must be the culprit. Right now I'm thinking the ABS module, which I can get for about $70 from eBay, used.

Some other thoughts, which may be of no matter, but I thought I should document them in case they click with somebody:

• The Autel scan tool is pretty neat. I go into it and tell it to service bleed the ABS and it just works. I can hear the solenoids doing their thing, clacking away. 
• I can press the pedal to the floor with the car off with... some effort. Maybe 65% effort. I don't need to brace myself against the seat or anything.  Pumping it makes no difference. I compared this to my wife's car to make sure I wasn't crazy, and it definitely goes to the floor much easier than her car. I cannot get hers to the floor at all.
• When releasing the pedal, car off or on, there is what I would describe to be a hissing sound. Is this just the booster's diaphragm sucking in air? Should it be making that noise? Could it be a vacuum leak? (but wouldn't that make an overly hard pedal...)
• Neither my bleeder valves nor my brake lines at the ABS/MC/calipers/shoes are leaking. No moisture at all. My fluid level stays steady.
• I bled so much fluid. Some of it on purpose, some of it by accident. My fluid is extremely clean now.

What in the world can cause soft brakes without having air in the lines or leaking fluid?

In reply to ValourUnbound :

I am still leaning towards the HCU being bad and a sticky solenoid in the system. I don't know the internal fluid pathway that this creates but it still sounds like what I had on my sons car. I think the Autel tool can actuate individual solenoids for troubleshooting but I could not get the system to respond any differently using this functionality. My assumption is that a stuck solenoid/valve remains stuck regardless of what you command it to do so no difference is noted.

yeah, it sure is starting to sound like maybe a leaking dump valve in the HCU, although the amount of fluid they allow into the accumulator (where fluid goes when ABS commands a pressure dump) is generally only a few CC's, and shouldn't result in pedal hitting the floor.

because i've had bad master cylinders out of the box (especially remans from A1 Cardone, those pigberkeleyers), i'm going to stick with my initial diagnosis.

Well, I guess I can do both simultaneously. Since the MC in the car is no different from the original MC, I can swap them back, send the "new" one back and get another one while ordering the HCU from eBay. I purposefully bought OEM in hopes that it would be a good part... Any recommendation on good brands? 

Looks like I can easily source Duralast, Raybestos, ACDelco, Centric or Cardone. Motorcraft is what I got first. The parts do not claim to be remans...

Regarding eBay vs junkyard, eBay, IMO, has the same likelihood of functioning as a junkyard part and then I don't have to crawl around in the rain.

hmmm, i would have recommended Motorcraft since it's a Ford vehicle.  ACDelco would be my second choice.  Both are reputable brands.