"White knuckle" moment - steep driveway, hard brakes, not stopping!

[lazer]

I believe what you experienced was "ABS at work". The ABS system is designed to prevent wheel lockup/skidding during a panic stop situation. And because there is no skidding SOUND it can give the impression that the brakes aren't working like they should - but they are actually working better for you than if you WERE skidding. (A lot of older drivers, like me, hate this about ABS - it reduces "feel of the road")

What I experienced over the weekend - in hindsight - felt more like I had little or no assist from the vacuum booster. Pressing hard on the pedal but little braking force. I'm going to have the dealer check it out (but I suspect they will say "no trouble found" - that's why I posted here to see if anyone else ever had this happen). I don't know if the altitude (~7000ft) or steep angle of the truck (about 40 degrees nose down) had anything to do with it but it was unnerving to say the least!

I know what skidding is like. I didn't need to skid, I just had to stop fast and the way my brakes acted they just slowed me down. Not very fast.

 

[boxofrokx]

I've had something similar happen before in my 2014 power wagon. Has actually happened multiple times but now I expect it and kind of ignore it. If I'm slowing the truck on the brakes lightly and then let off and suddenly reapply hard, there is very little braking power. It was looked at a few times but it seems to be what the dealership said is the nature of the beast with the vacuum braking system. It was very disconcerting at first but for better or worse it's a quirk I now expect. And no, it is definitely not ABS kicking in. In fact most times I've noticed that it's been completely dry

My '15 PW has done the same. I usually notice at the worst time, bumper to bumper traffic going 40-55. First stop is light peddle pressure, building to moderate followed by a near panic stop. No throttle and little time between. The panic stop has little to no boost. IDK why, I guess from learning to drive in a manual brake car, my leg is usually in a possition were I can provide full leg strength and get the job done.

 

[Craig Muszynski]

My '15 PW has done the same. I usually notice at the worst time, bumper to bumper traffic going 40-55. First stop is light peddle pressure, building to moderate followed by a near panic stop. No throttle and little time between. The panic stop has little to no boost. IDK why, I guess from learning to drive in a manual brake car, my leg is usually in a possition were I can provide full leg strength and get the job done.

Exactly this. Its like there's far too little reserve vacuum. I've wondered if an auxiliary vacuum reservoir would help

 

[Craig Muszynski]

...or the reason some switch to hydroboost?

 

[Jebb]

Did you get in and apply the brake before starting? Maybe you didn't let back off to allow the brake booster to work. Maybe if you pumped it once it would have kicked in.

I was hoping this was the simple cause but I did another test yesterday and it appears to be a real problem. When stopped at a traffic light I can push the brake pedal all the way down to it's mechanical stop. It takes a bit of effort to push it down that far but when I was on that steep hill that day THAT is what I felt - pedal pushed to the floor and still rolling!

In normal driving I rarely need that much braking force so I never felt this until that day on a steep incline. Needless to say a panic stop or boat ramp might be a total disaster! Now I AM worried - and off to the dealer.

So, it seems my 2017 truck with 4100 miles on it has AIR in the brake lines. How did that happen - or was it like that from the factory?

 

[gofishn]

let us know what you find out.

 

[Jebb]

My '15 PW has done the same. I usually notice at the worst time, bumper to bumper traffic going 40-55. First stop is light peddle pressure, building to moderate followed by a near panic stop. No throttle and little time between. The panic stop has little to no boost. IDK why, I guess from learning to drive in a manual brake car, my leg is usually in a possition were I can provide full leg strength and get the job done.

OK, guys - it's been awhile since the stealership told me everything was OK - BUT IT' S NOT OK - THERE IS SOMETHING SERIOUSLY WRONG!

This week I had a chance to test the truck in the mountains (~7800 ft elevation) where I first experienced this issue.

In the attached photo I am the only person in the truck, 1/2 tank of gas and about 150 pounds of stuff in the bed - i.e., very light load. The truck is idling in gear ("D") and at the position shown I CAN'T STOP IT! I have the brake pedal mashed to the floor yet I roll all the way down to where the driveway flattens out to the road before I can stop. It's hard to see in the photo but the pitch at this point is about 40 degrees (80% grade).

I made sure to cycle the brakes a few times before I headed down - so lack of vacuum, etc., is NOT the cause.

THIS IS SERIOUS SAFETY ISSUE! If I had a load of firewood in the bed or a trailer behind me I would be out of control.

I have not noticed any issue when driving on flat ground - and I hope I never do - so this seems to be a problem with pitch or maybe the ABS system.

Can someone who has access to such a step grade please try your truck and advise the result?

My truck only has ~6700 miles on it. Brake pads are factory. Dealership tested it (on flat ground) and said it was per spec!!!!

 

[bm02tj]

If the pads are cold they donot work as well and if you just started your truck it will push you down the hill
and with the low gearing in the trans it will be hard to stop
I have a complaint in for my 18 as it pushes until warm

 

[Jebb]

If the pads are cold they donot work as well and if you just started your truck it will push you down the hill
and with the low gearing in the trans it will be hard to stop
I have a complaint in for my 18 as it pushes until warm

And NONE of that is acceptable! If my wife drove this thing down the hill she would panic - and rightfully so! It was 85 degrees the day this photo was taken. What will happen in the winter when it's 20 degrees - or if I have to stop fast on the freeway after not using the brakes for awhile - or I'm coming down a steep mountain road at 30mph?

I just reported this to NHTSA. Something's seriously wrong IMO. I've never had another truck I couldn't stop like this. I love my truck but this is just downright frightening.

 

[bm02tj]

My complaint is with the programmers I tried every way I could then for chuckles I left my house and when I started down the hill I set the cruise a 50Km /31 MPH in drive to see what the program would do
it down shifted until I was in second gear and RPM got up to 4800 RPM
part way down the hill the computer was happy and removed the throttle
truck slowed then shifted up to 3rd
This was on a 9% grade
FCA either is not smart enough to fix or does not care
I hope they can fix your problem as that is unacceptable
good luck

 

[DeckArtist]

That’s a serious problem! You definitely are following the right track being the squeaky wheel on this one, no pun intended, you need to be shouting this at every opportunity. On your next call mention you have in mind talking to the media. It’s amazing how fast some people will act when they think they’re going to be negatively represented on TV.


Sent from my iPhone using Tapatalk

 

[Jrod]

I was hoping this was the simple cause but I did another test yesterday and it appears to be a real problem. When stopped at a traffic light I can push the brake pedal all the way down to it's mechanical stop. It takes a bit of effort to push it down that far but when I was on that steep hill that day THAT is what I felt - pedal pushed to the floor and still rolling!

In normal driving I rarely need that much braking force so I never felt this until that day on a steep incline. Needless to say a panic stop or boat ramp might be a total disaster! Now I AM worried - and off to the dealer.

So, it seems my 2017 truck with 4100 miles on it has AIR in the brake lines. How did that happen - or was it like that from the factory?

Following,

I’m having the same exact issue with my 16 sport. I’m at 52k miles. A couple of months ago I installed new aftermarket rotors and pads on the truck. I took my truck in and they replaced my master cylinder under Maxcare. I also paid out of pocket to have my brake fluid flushed and replaced. The service manager told me all they can do is keep throwing more parts at it if it doesn’t help. I felt some improvement leaving the dealership, so I left it at that.

A couple of weeks ago I picked up half a cord of wood with my 4x8 high side trailer. As I pulled out of the (flat) driveway with the load I had to mash the brakes for an incoming car. I had literally just put it in drive and taken my foot off the brake. My truck came to a gliding stop of about 12 feet. I was half way across the lane. Fortunately the other car had good brakes. Needless to say it was a 40 minute nail biting drive on the freeway to get back home.

Today I ran to the gas station to fill up a gas can for yard work. The car in front of me slammed on his brakes, and once again I came to a gliding stop without a load. Fortunately I had enough space between us to avoid rear ending them.

I was about to cut my losses with my new pads / rotors and just have the dealership install theirs tomorrow. But, after coming across this post I’m guessing it will not fix the problem.

 

[indept]

It makes you wonder if the antilock brake pump/ mechanism isn't the cause. I remember a little over a year ago having to stop quickly and feeling like I wasn't going to stop.

 

[Jrod]

It makes you wonder if the antilock brake pump/ mechanism isn't the cause. I remember a little over a year ago having to stop quickly and feeling like I wasn't going to stop.

No idea since mine does it from a dead stop, release the brake, then mash the brake with a approximately 1200lbs (trailer plus load). And also from any cruising speed. Like the OP, it also stops normal under normal braking condition.

As of right now, I refuse to attach my trailer again. I’m also trying to fix the problem before our annual winter ski trip. I will not take my RAM into the mountains, with or without snow, until the problem is fixed. The last thing I need is to brake on a descend and not stop. It’s frustrating to say the least.

 

[Jebb]

I will not take my RAM into the mountains, with or without snow, until the problem is fixed. The last thing I need is to brake on a descend and not stop.

I can't believe it's not a major recall. Please report it!

https://www-odi.nhtsa.dot.gov/VehicleComplaint/

 

[Jebb]

It makes you wonder if the antilock brake pump/ mechanism isn't the cause. I remember a little over a year ago having to stop quickly and feeling like I wasn't going to stop.

ABS is supposed to keep you from skidding - it's not supposed to prevent you from STOPPING!

Please report your experience: https://www-odi.nhtsa.dot.gov/VehicleComplaint/

 

[Amos]

It makes you wonder if the antilock brake pump/ mechanism isn't the cause. I remember a little over a year ago having to stop quickly and feeling like I wasn't going to stop.

I had this exact same scenario a few years ago. Although not on a Ram. It was a bad abs sensor. I had to pull the fuse until I fixed it.

 

[Jrod]

I had this exact same scenario a few years ago. Although not on a Ram. It was a bad abs sensor. I had to pull the fuse until I fixed it.

Curious, did it produce a code / ABS light come on?

 

[Amos]

Curious, did it produce a code / ABS light come on?

To be honest I don't remember. The light did come on after I pulled the fuse though.

 

[Jrod]

I know this won’t help, assuming the factory pads and rotors are still on the truck, but yesterday I decided to buy and re-install OEM pads and rotors from the dealer. It seems to have fixed my issue.

The aftermarket pads and rotors I installed a few months ago were slotted and drilled. The pads I purchased with the set also covered less surface area because they were curved out at the ends. So, in my case it seems less contact with surface area between the pads and rotors was the culprit.

My truck brakes normal again after re-installing OEM pads and rotors. I can even feel the ABS engage again when performing a hard stop at highway speed.

I’m sure a less expensive aftermarket set would produce the same result. I would just make sure the rotors are solid and the pads are flat, from end to end, in order to maximize contact.

I hope you figure yours out soon.