freswick

I have a 2012 Mustang and lately just out of the blue when I come to a stop the brakes aren't working. I just keep pressing pedal to the floor and car keeps rolling. Finally will stop. This happens very intermittently. Maybe every three to four days. Had brakes checked out and service can't find anything. Said it could be ABS system but I am not getting a light on dash for that when it happens. What do I do?

Mustang Freak

Stop driving it until you get it fixed would be my first suggestion! Good luck and hopefully it's something cheap to correct.

David Young

I have no ideal what is going on with your brakes. Was it a Ford dealer who looked at your Mustang?

freswick

It was not a Ford dealer who looked at my brakes although my husband stopped by the Ford service dept. and described the problem. Ford said if it was the ABS system I would have got a light on my dash. I don't know what to do.

Bert

does the pedal pulse when it does this, like the ABS was activated?

has anyone checked for codes?

It is strange that it is intermittent, that does suggest something electronic malfunctioning like maybe the ABS. There could be codes stored in the system that are not triggering a light on the dash. They can be read with an ODBII diagnostic scanner.

The usual culprits are air in the lines or badly worn or glazed pads; but those would not be intermittent.

houtex

That's... disturbing. Air is the first thing, no fluid is the second thing, broken brake pedal to master cylinder is the third thing, ABS pump/solenoid pack third...

Of course, you could be exaggerating the actuality of your situation and the pedal's not actually going to the floor, in which case... one, whew, and two, need to be a little bit less dramatic and more descriptive before you keel one of us over with heart problems.

But if you are being completely serious... yeah. That's disturbing. And weird that it's intermittent.

http://iihs.net/fsm/?d=763&f=Symptom%20Chart.pdf&p=2

That's the symptom chart for your car. Really, for a lot of cars, but for yours specifically-ish, being a 2011 manual. Still. Go down the list and find what applies, and then you'd have the likeliest issues to check.

I'm wondering if the master cylinder's rear seal is leaking into the booster so you don't see the fluid (yet), but it's still causing the non-pressure.

Overall, this potentially requires an expert and perhaps even scan tool to let the car tell you/them what's the problem. Not any ol' mechanic's necessarily gonna have all the things(tm) to do the jobs. Lots of different systems out there. Eric O of South Main Auto might can do it, he seems to buy/get everything. But he's kinda an exception to the overall rules of mechanics: Detail oriented and fantastic at his work. No offense to mechanics overall, of course, but... you guys know what I'm sayin'. I work with mechanics at part of my job, but I can tell you there's a very few I'd even let touch my car, beyond a Ford Dealership and even then, I'd rather do the work myself than let the Ford guys on it... unless I know them good. And on this... it's probably going to the Ford Dealership. ABS system isn't something I'm familiar with nor have the tools, and brakes are too important to not have right. I'll do the pads, no problem. Maybe the booster. I gotta crack open/relearn the ABS? Nope. Not yet anyway...

The hardest part is that they'll have to replicate it. Which means that the best option is to figure out how to *reliably* replicate it so they can do it themselves. In the air, maybe, on the lift, but still. If they/you can't reliably hit that problem, then the car is absolutely *undrivable* and you need to park it. And start saving up for an *entire front to back* replacement brake system, because if you can't replicate it... it's ALL suspect.

Probably not the answer you want, but there it is. Sometimes the dealership is the only way to do it... even if I don't wanna.

Welcome to the forums, hope that helps!

/I'm suspecting the master cylinder or the ABS solenoid pack, m'self...

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Edit: WAIT. Hang on.

Bulging brake hose at a corner or two?

Naaaahhh....

freswick

My car is a 2012.---Thank you for your answer but I don't appreciate being told I could have been over dramatic. I was almost hit by other cars after not being able to stop at an intersection. That was beyond dramatic.

Mustang Freak

Not to be a jerk here but your post can be interpreted several ways. First it read like you continue to drive your car even though it doesn't stop. I don't recall you saying you almost had any accidents so this is the over dramatic interpretation. Now a car not stopping and maybe getting into an accident is an automatic heart stopper for all of us! Me personally I'd be driving my lawnmower or bicycle before I'd drive my Mustang even if it is your DD. Because I don't know rearend a family of four and kill them all?

houtex

Ok, well, time to be a little harsh and even more wordy about this I suppose. I don't like doin' it, but... yeah. Explanation is a thing that must now happen. And Caps are for emphasis because that's important now.

regarding this:
First, I'm insane. The GIR on the left shoulda told ya(*). So there's that, sorry.

Now... I said 'could be exaggerating'. That wasn't a factual accusation, but people DO do that. But I right after stated the why of the 'perhaps needing to be less dramatic' because going to the floor is *SERIOUSLY WRONG* and if you weren't actually having that happen, that's kind of important in trying to diagnose the problem here. And it wasn't exactly that clear in the previous posts to me, or I'd have not said it at all. Because there is NO CIRCUMSTANCE WHATSOEVER that a brake pedal going all the way to floor is in any way, shape, or form good. And so it is that I wanted to convey that what's sometimes described to us is not what's happening, and clarity is important. Because the truth is... nobody actually drives a car with their brake pedal going to the floor and continues to drive it... do they?!

But for sure, NOW I'm worried.


You stop driving the car and do not drive it until it is VERIFIABLY FIXED. You park it, have it towed to a Ford Dealership and get it fixed, pay the man/woman. That's what you do.

The manual I pointed you do is for a 2011, truth, but that manual applies to all 2011-2014 Mustangs in this regard. But you are certainly welcome to source a 2012 specific manual and compare the two if you'd like. You won't find anything except some cosmetic panels or maybe a newer function in the cockpit that the 2011 doesn't have, but nothing concerning the brakes/engine/transmission/axle/suspension/windows/seats/etc/ad nauseam changed in any significance between those years.

If your mechanic has no idea what's wrong with it, then they are the wrong mechanic. For this job, admittedly, maybe not others, but still. I'm not saying he's not competent, but as with all things, there's always something persons/entities do not know. This is one of them, and maybe it's dealership time. Still, with that manual, and the proper tools and know how, this problem should be solvable. Some of the tools are expensive scan tools, and that's due to the ABS system. Otherwise, it's a really straight forward brake system: pedal, switches, brake booster, master cylinder, brake lines, brake hoses, calipers, and a clutch line. With fluid involved. The ABS module makes it a little complicated, but even then... not that much so, it's the communications/resetting/calibration that's the fun part.

But overall, if you can't work on it, and you can't find someone who can work on it and also knows *how* to work on it and fix the problem: Park it. Do not taunt happy fun death trap Mustang.(*) Get it properly fixed, at the dealership (or reputable verifiable good shop that can work on this, like FordTechMakuLoco or maybe Eric O. of South Main Auto (you can find those two on youtube, good stuff!), or other VERY competent mechanic with ALL THE THINGS to do the job), because ONCE is the only time you should have ever experienced the brake pedal going to the floor and no brakes. Period. Full dang stop.

That it's happened more than once... THAT's not appreciated. Like at all. Stop doing that, please, and thank you.

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Ok. Said my piece, I'll be done with this thread, likely. You have your recommendations, and I hope they do some good for you. Maybe report on how it got fixed, we're here to learn as well as help, but that's more on your situation now than us figuring it out across the interwebs, from WAAAAAY over here/there/everywhere... So if you do have information to report, please, let us know! It may save US, and that's a good thing!

That said... I hope I and/or others in this thread do not/have not turn(ed) you away from this site, because we're by and large a great lil' group of people who DO care, both about Mustangs and about the people who drive them. You should be safe, and that's the concern here. That I try to inject some humor here and there to tweak away some of the harshness is one of my idiotsyncrasies. Yes I spelled that correctly... for me. Take that as you will.

I do hope that all helps, but above all, I do hope you get that car fixed and back to not worrying about the brakes. That's the bottom line here. I wish you good dang luck in a speedy and proper fix on those things.

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(*) - Vignettes to amuse. Mainly me, I'm guessing, but doin' it anyway.

Bert

This is the "friendly Mustang forum" ; I wonder what kind of reaction this would get on some of the less friendly ones, LOL?

To the OP -- when you come for free mechanical advice you might have to take a little humor or unwanted safety advice along with it; brake failure is probably the most dangerous thing that can happen on a car so hopefully you understand the concern. I assumed you were not driving the car but maybe that was not a safe assumption.

Anyway, let's relax and cut each other some slack; there are plenty of other things to argue about out in the world outside this forum

I stopped replying to this thread because I didn't have any more to add, regarding the problem . . . still don't.

Hershey

How many miles are on the brakes? How is the brake fluid level ?
Check the simple things first. But take the car off the road till fixed before you kill somebody.


Hershey