Bronco Free Rolls (Falls) Off Steep Hill!!

[LMF Bronc]

So I am no expert off roader, however, I would hardly say I'm green. This happened today and I am at a loss, possibly financially, but more importantly I don't know what actually went wrong. I have wheeled plenty of times in this Bronco since Aug 2022, I have been up this hill...successfully twice before...with plenty of witnesses. I have been up many other hills, in fact this wasn't even the steepest today, as I had done a 39 degree hill earlier, this one was likely upper 20's, lower 30's. I have stalled the Bronco before, it's always restarted before and I've never lost brakes no matter at what angle and what grade. So I really have no idea what caused this. It stalled out around a 1:00 in and I lost power to everything. I did like everyone else yelling brakes, LOL! Tailgate is shot, bumper is shot, driver mirror also shot. It appears that the quarter panels and hardtop were unharmed.

Concerning repair, yes this is posted, either Ford or my insurance will cover it or they won't. If Ford won't I will try my insurance, if this is excluded from coverage, shame on me for not having this coverage, I will not commit insurance fraud in case anyone calls me stupid for posting this. My real aim is to figure out what went wrong. Total damage best I can figure is roughly $3000-4000. Oddly the real rip off is the side mirror based on my quick research.

So totally unrelated to the thrust of your post, but I noticed when you were trying to get over the rock at one point you apply the clutch and you can hear 4-5 quick click noises. I have the same noise on my 2 door manual Sasquatch, seems to be coming from the front left possibly transfer case. I get it when in 4wd (usually 4lo) and I have the drivetrain loaded up then released such as by applying the clutch. I may also get it when going over larger obstacles where the suspension compresses and rebounds. Are you experiencing the same symptoms?

edit- noise occurs at 1:04 in video

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[BroncoJoerg]

There might have been no error code. ABS worked as it should and was simply tricked by the combination of several factors: the loose surface, locked rear diff, and the front left wheel that lost traction right before the Bronco began to roll downhill.

So, not a failure, but a "trick" situation? I'm thinking I need to take my Bronco out and run some tests to see how it reacts in different scenarios. I have an automatic, so I suspect it will be different in the same scenario than the manual. I'd prefer to learn under a controlled condition though!

 

[FloridaBurgBronco]

So totally unrelated to the thrust of your post, but I noticed when you were trying to get over the rock at one point you apply the clutch and you can hear 4-5 quick click noises. I have the same noise on my 2 door manual Sasquatch, seems to be coming from the front left possibly transfer case. I get it when in 4wd (usually 4lo) and I have the drivetrain loaded up then released such as by applying the clutch. I may also get it when going over larger obstacles where the suspension compresses and rebounds. Are you experiencing the same symptoms?

edit- noise occurs at 1:04 in video

Yes, that seems to be a common sound, usually in 4L, it's likes it's when it's transitioning from one gear or maybe load to the next. I think I'm not describing that well enough. I just assumed that sound was normal as that sound likely has nothing to do with what happened here. Some have asked about it, but like you, that is a sound I have heard many times before, all without incident.

 

[Bmadda]

Hey guys, thanks for all the replies. I think a lot of these were very helpful in trying to figure some things out. I just want to make clear what happened to answer some questions, maybe this will help in the future, maybe not, hopefully with these experiences, despite being painful, maybe we can learn.

Sequence of events.

First off, let me just say what was weird. I have done this hill twice before and I have stalled before, both in 4L and 4H and never had this happen. Now maybe something was different, maybe not, like maybe the incline at stall was higher, but I'm pretty sure I stalled earlier in the day on a 39 degree hill (this one was upper 20's/low 30's), and I was in 4L with both lockers on and the sway bar DC, "full war package" so to speak.

-Went up, there is a rock that is difficult to traverse, but had before.

-I was trying to get another better angle.

-I did shift from C to 1st to get more wheel speed versus engine rpm. I'm not a "send it" kind of guy, I usually like slow and steady, but sometimes momentum can be your friend, even if it often is not. Please pay little attention to the scraping sounds, I have enough skid plates to armor a WW2 battleship.

-I think maybe I didn't feather the clutch just right in 1st and that's when I stalled. Not positive, but seems likely, it happened pretty quickly.

-I think at that point it stalled and I may have lost all vacuum pressure for the brakes and the engine would not start.

-I rolled back with the clutch pushed in and the foot on the brake, so using both feet for the brake and clutch, but unlike every single other time I've ever had to auto-start the vehicle, it simply did not this time, so the issue wasn't a direct brake failure to be clear. There was no power to the brakes and I could not manually push hard enough to engage the brakes.

-At this point the Bronco rolls back without me being able to stop it. Also at this point, I am stunned because it won't restart and am in WTH mode. Passenger side hits a rock, that's the pop up in the video, which does two things, destroys the bumper and thankfully actually slows it down...a little.

-The rest of the way, I am trying to restart, so I am pressing again, both clutch and brake in. Aftermath was kind of funny people yelling brakes, sorry silver lining joke, because I already knew to do that.

-I probably hit the smaller tree at I would guess was 10-15mph. I think the tree or rather the tree hitting the spare tire saved the body and hardtop. And because it was tight, I lost the driver mirror to incidental contact as I rolled down the hill.

So here are some questions/thoughts. As I read the comments, maybe there was nothing wrong with the Bronco, maybe it did what it was supposed to do, like it doesn't start in certain situations. So, I thought maybe I just reacted too slow and I'm all to blame for this. And I should have popped the clutch and jumped started the manual transmission vehicle to regain power brakes. But I saw some folks mention that you can't roll start a 6G Bronco, funny enough after reading that, I called me kids out to help me push and try and it does not, WTH Ford, that's one of the advantages of a manual, a dead battery will never stop you...sort of.

So, it seems I could not have started it again, therefore never giving me brake power back.

So, could I have put it in gear and popped the clutch and it may have just stopped there on the hill? I mean, I guess what I'm saying is, what is the fix if you lose brake power and can't pop the clutch to restart?

I think about the new Defender commerical where they back up to the ledge and stop, well what happens when you do that in a Bronco and it stalls? Am I just supposed to jump out quickly before I go over the edge, geez. Obviously extreme example, but nonetheless possible based on events two days ago.

OH ONE LAST THING, IT DID HAVE A SERVICE VEHICLE SOON LIGHT ON AND SAID 4X4 DISABLED AFTER THE ACCIDENT. At this time, I needed 4X4 to at least get out of the park, so I turned the vehicle off, locked it, unlocked it, restarted it and the service vehicle soon light was gone and 4X4 was enabled again. I wanted to keep the codes in there but I wasn't going to keep the vehicle on until Monday morning taking it to Ford, plus they didn't occur until AFTER the accident.

My hope is this clear up some questions that people have had.

So, to be clear on the chain of events, you never moved the shifter? If you were still in 1st you would not have restarted the engine by dumping the clutch anyway...even on old non electronic vehicles. You would have had to shift to reverse, then dump the clutch. However, if you had dropped the clutch, and put both feet on the brake, you would certainly have stopped the vehicle, or at least slowed it to a very slow crawl? I am not criticizing your actions...I get it! In the moment, you were focused on restarting the engine, which requires the clutch to be fully depressed...ergo you never released the clutch pedal, and gravity (harsh mistress that she is), continued to accelerate the vehicle. My point being if you had been able to restart the engine, it woulda all worked out...whether that was the "technically right" way to do it or not! And I continue to be baffled as to why this is not possible on a 6g Bronco! I personally would like an explanation from somebody as to why?

 

[FloridaBurgBronco]

So, to be clear on the chain of events, you never moved the shifter? If you were still in 1st you would not have restarted the engine by dumping the clutch anyway...even on old non electronic vehicles. You would have had to shift to reverse, then dump the clutch. However, if you had dropped the clutch, and put both feet on the brake, you would certainly have stopped the vehicle, or at least slowed it to a very slow crawl? I am not criticizing your actions...I get it! In the moment, you were focused on restarting the engine, which requires the clutch to be fully depressed...ergo you never released the clutch pedal, and gravity (harsh mistress that she is), continued to accelerate the vehicle. My point being if you had been able to restart the engine, it woulda all worked out...whether that was the "technically right" way to do it or not! And I continue to be baffled as to why this is not possible on a 6g Bronco! I personally would like an explanation from somebody as to why?

To be perfectly honest, I don't know if I shifted again to another gear, most likely not, as I was focused on the restart, but yes, if in 1st, it would have just stopped or maybe turned the engine backwards, but very slow anyway. But if I was thinking, apparently to no avail, I would have shifted to reverse and dumped the clutch, but as I said as well as the other commentor, you can't dump a clutch in a 6G Bronco and get it to restart, completely new and sad news to my ears, just found that out tonight. I believed him, but it was easy enough to test and confirm myself, YOU CANNOT restart one. Yeah, so yesterday and today, I was just thinking I screwed up and didn't do the things I needed to, now a day and many comments later, it sounds like even the things I thought I could do would have had little affect, which leads me to what the heck could be done? I don't know yet

 

[Bronco1010]

To be perfectly honest, I don't know if I shifted again to another gear, most likely not, as I was focused on the restart, but yes, if in 1st, it would have just stopped or maybe turned the engine backwards, but very slow anyway. But if I was thinking, apparently to no avail, I would have shifted to reverse and dumped the clutch, but as I said as well as the other commentor, you can't dump a clutch in a 6G Bronco and get it to restart, completely new and sad news to my ears, just found that out tonight. I believed him, but it was easy enough to test and confirm myself, YOU CANNOT restart one. Yeah, so yesterday and today, I was just thinking I screwed up and didn't do the things I needed to, now a day and many comments later, it sounds like even the things I thought I could do would have had little affect, which leads me to what the heck could be done? I don't know yet

Hey man glad to see that you are ok. I'm just wondering though. Is it possible you shifted from crawl to reverse? I watched the video over and over. That loud noise when you shifted you see the wheels rotate backwards then it stops. Then it looks like you went to move forward and the front wheels appear to accelerate backwards.

Maybe it wasn't you that went into reverse. Maybe the trans went into reverse event though you were in first position? Idk

Glad that you are ok though.

 

[Alanp970]

Could this be related to what I and others have posted about - loosing brake boost? Mine has done it twice at slower speeds but always while still running. Mine barely stopped on flat ground so a hill would be completely uncontrollable like yours. I think there’s a problem with the vacuum booster on the 2.3’s but it’s so random I can’t reproduce it. One of these days Ford is going to issue a recall on it when they stumble across the problem but who knows how long that will take

 

[ac360]

Whatever the circumstances may be, the brakes should always work. The fact that OP does not have brake function is absolutely a problem.

 

[NJRoadkill]

Yes, that seems to be a common sound, usually in 4L, it's likes it's when it's transitioning from one gear or maybe load to the next. I think I'm not describing that well enough. I just assumed that sound was normal as that sound likely has nothing to do with what happened here. Some have asked about it, but like you, that is a sound I have heard many times before, all without incident.

It’s hard to explain to people who don’t own it… sounds like that every time it stalls under load. If I try to brake boost(2 pedal) it stalls. If I try to “bump” the clutch it just smokes it. The situation doesn’t happen often, but when it does it didn’t leave me feeling confident.

Since day one I noticed you can’t 3 pedal, feather, pop the clutch, and/or brake boost. It either smokes it or stalls. It doesn’t let you use the clutch as an additional tool to control power.

The system really wants you to pick the “right” combination of 4L/4H and gear, engage the clutch fully, then slowly chew over the obstacle. But you can’t always do that, so you try to ramp up the torque/rpms. When it stalls while trying to pop over an obstacle, it is so wound up, it actually throws you back. I could hear it. That when I’ve felt the systems feel sketchy. Even had it throw ABS codes. Im sure I’m not explaining it well, but anybody who owns the M7 will get it.

Has anyone installed a South Bend Stage Kit yet?
https://www.southbendclutch.com/clutches/13310/

 

[Willub]

Damn, that sucks. I’ve hopped in mine, thrown it in neutral and rolled it down the driveway without starting it. I’ve done this with many other manual trans vehicles and the Bronco is bad at stopping with no vacuum.

Whether throwing it in gear and letting the clutch out would have stopped you or not, it at least would have created vacuum to allow the brakes to work again, or at least I’d hope it would. The engine doesn’t need to be running to create vacuum, just needs to be turning over.

 

[Willub]

It’s hard to explain to people who don’t own it… sounds like that every time it stalls under load. If I try to brake boost(2 pedal) it stalls. If I try to “bump” the clutch it just smokes it. The situation doesn’t happen often, but when it does it didn’t leave me feeling confident.




Has anyone installed a South Bend Stage Kit yet?
https://www.southbendclutch.com/clutches/13310/

A lot of newer vehicles cut throttle if you press the gas and the brake at the same time. It’s to prevent old people from hitting both at the same time and ramming straight in to a McDonald’s. That’s my thought at least.

 

[FloridaBurgBronco]

Damn, that sucks. I’ve hopped in mine, thrown it in neutral and rolled it down the driveway without starting it. I’ve done this with many other manual trans vehicles and the Bronco is bad at stopping with no vacuum.

Whether throwing it in gear and letting the clutch out would have stopped you or not, it at least would have created vacuum to allow the brakes to work again, or at least I’d hope it would. The engine doesn’t need to be running to create vacuum, just needs to be turning over.

Yeah, I would like to find a good safe place to play with this issue again, but I'm not sure how to bleed out enough vacuum to duplicate the issue again. Also the vehicle just stops when you pop the clutch, so would the engine rotate enough to create enough vacuum? I don't know, I'm just asking.

 

[FloridaBurgBronco]

A lot of newer vehicles cut throttle if you press the gas and the brake at the same time. It’s to prevent old people from hitting both at the same time and ramming straight in to a McDonald’s. That’s my thought at least.

Yep, I have heard that also, but I never touched the gas, that is the one thing I'm sure of.

 

[Willub]

Yeah, I would like to find a good safe place to play with this issue again, but I'm not sure how to bleed out enough vacuum to duplicate the issue again. Also the vehicle just stops when you pop the clutch, so would the engine rotate enough to create enough vacuum? I don't know, I'm just asking.

Absolutely. It’s about what gear you pick. Pop the clutch in second or third while free rolling and the engine will turn rather than lock tires and stop like it may do in first.

 

[GreyZ]

Yeah, I would like to find a good safe place to play with this issue again, but I'm not sure how to bleed out enough vacuum to duplicate the issue again. Also the vehicle just stops when you pop the clutch, so would the engine rotate enough to create enough vacuum? I don't know, I'm just asking.

You bleed out the vacuum when you you have your foot on the brakes (diaphram is moving) and stall the engine by letting the clutch out without enough throttle. The ecu tries to keep the engine running but adding throttle when its about to die. This kills the vacuum and when it happens with the brakes applied it also reduces the vacuum in the booster.

This is a tough way to learn. The correct move would have been to make sure its in gear, get off the clutch asap and start pulling on the e brake asap. Same movements when you kill and start rolling in any other manual trans off-roading.

This is the exact same order of events that occurs in any electronic throttled manual vehicle. This is not Bronco specific.

Once you are stopped, engine off, clutch out, in gear with the ebrake on you can take a breath and regroup. In this situation you would want to shift into crawl and start in gear without the clutch. This will get you moving immediately. Then you can apply regular brakes and clutch, turn off the ebrake, select the gear you want and try again.

Getting fast at letting out the clutch and pulling the ebrake is of the highest importance when off roading and you experience a stall.


Get use to the electronic ebrake and practice emergency applications of it.

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