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

[Jebb]

Weird little "white knuckle" moment this weekend in my 2017 Ram QC 4x4. I was idling down a steep driveway and when I got to the bottom I was mashing a hard brake pedal and still rolling. If a car had been coming down the street I would have likely rolled right out in front of him!

Truck is a 2017 Hemi QC 4x4. Only has 4000 miles on it.

Driveway was very steep but was clean and dry and around 55F. I heard no tires sliding and no ABS light or chime. Truck was in 2H DRIVE at the time and idling - brakes should have held it.

Never felt this before and everything seemed normal afterwards (truck stops fine). I wasn't able to repeat it as my family was with me and I didn't want to alarm them.

Needless to say this was a little concerning! What could have caused this? I'm thinking something in the ABS system was kicking in but if that's the case it's NOT good!

 

[turkeybird56]

Wow, dunno, especially if not repeated. Is it possible U hit the "neutral" button on transfer case switches (though this should have no effect on brakes, just thinking out loud)??? Any codes thrown? Air in master cylinder main line, low fluid, see ne fluid leak at a brake to indicate leaking caliper or line, If happens again, mash emergency brake and definitely get checked out, too many causes, all IMHO... Definitely not thinking ABS system, but who knows with these electrical gremlins popping up

added: the MY 19's do not have E brake [pedal], all electronic, bet if I get in the situation, I break my left leg, lol, but still not funny, Just Saying

 

[dexter]

Need a new brake master cylinder?

 

[turkeybird56]

Hmmm, with only 4K, thinking more of a bad vacuum leak, but the ECU should have thrown a code and the "Brake" light should have illuminated and code stored, but who knows, friggin GREMLINS...

 

[McBroom]

Dealership checkup


I Love my 18 Ram 2500HD 4x4 CC
Blue Streak Pearl off-road

 

[grizzstang]

I have experienced this with a well worn master cylinder.

Light braking followed by harder braking seemed to let the fluid by the seals, the peddle would go almost to the floor and stopping was difficult, otherwise braking was normal.

I am betting you have a bad master cylinder. Your truck has too low a miles for it to be worn obviously but it could definitely be faulty.

 

[WilliamS]

even if there was a massive vacuum leak you can muscle the pedal down to stop. Did you just get back from a long mountain trip or anything that would have superheated the brakes?

 

[Jstmahoney]

I’d take it in to the dealer, have them check it over. Even if they can’t come up with something at least you have a record/case if it happens again.


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[JoshR104]

Any chance it had rained a lot and rotors possibly were quite rusted? I know mine after sitting a few days if I shifted from park to drive while warming up it would jump forward a few feet with my foot on the brakes although they would have to be quite rusted to not grind off after going just a few feet. I would 100% be taking it to the dealer as even if it never happens again why risk it?

 

[Jebb]

Thanks for all the replies. Truck is 1 year old but I haven't driven it much (I retired last year - no more daily driving ). There was no rain or any other "environmental" cause AFAIK, no codes, no CEL, no chimes, etc. We were up in the mountains (~7000 feet) so maybe there was a vacuum issue (not enough?) but still should have been able to muscle the pedal to a stop.

Not a pleasant feeling for sure!!

The truck currently has 3 recalls against it (cruise control, autopark and tailgate latch) so when I take it in I will have them check this out too.

 

[turkeybird56]

HECK yeah, check, square it away and BE SAFE, IMHO

 

[lazer]

I had the same thing happen. I have a 13 Ram 1500 and a car pulled out about 6 feet in a intersection, I was doing about 40-45 mph and hit the brakes very hard and it felt like I drifted to a stop. I was more worried about how my truck tried to stop than the guy that pulled out in front of me.

 

[Jebb]

I had the same thing happen. I have a 13 Ram 1500 and a car pulled out about 6 feet in a intersection, I was doing about 40-45 mph and hit the brakes very hard and it felt like I drifted to a stop. I was more worried about how my truck tried to stop than the guy that pulled out in front of me.

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!

 

[Black W900]

At that angle it's remotely possible that if the fluid is low that it wasn't picking it up.
It would have to be pretty damn low for that to happen though, which would indicate that there is another, underlying problem.

 

[magic280z]

I know on motor cycles and my old truck abs doesn't engage until you hit a certain speed so that it is able to do a self test. So you should have had real brakes. 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.

Sam

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[RamCares]

Weird little "white knuckle" moment this weekend in my 2017 Ram QC 4x4. I was idling down a steep driveway and when I got to the bottom I was mashing a hard brake pedal and still rolling. If a car had been coming down the street I would have likely rolled right out in front of him!

Truck is a 2017 Hemi QC 4x4. Only has 4000 miles on it.

Driveway was very steep but was clean and dry and around 55F. I heard no tires sliding and no ABS light or chime. Truck was in 2H DRIVE at the time and idling - brakes should have held it.

Never felt this before and everything seemed normal afterwards (truck stops fine). I wasn't able to repeat it as my family was with me and I didn't want to alarm them.

Needless to say this was a little concerning! What could have caused this? I'm thinking something in the ABS system was kicking in but if that's the case it's NOT good!

Hi Jebb,
I completely understand why this would be so concerning. Send us a private message if you decide to have your dealer look into this so we can get a case started for you where a Case Specialist can work with your dealer to help find a potential solution.
Lydia
Ram Social Care Specialist

 

[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.

Sam

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That is entirely possible! I had to turn around before coming down the slope and I had just started the engine. The engine idles fast when first started so, yes, I likely had my foot on the brake the whole time. Yep, never thought of that! Will check this out myself before running to the dealer (and having them spend a day searching for possibly nothing).

Good put! Thanks for the suggestion!

 

[John-e-racer]

Weird little "white knuckle" moment this weekend in my 2017 Ram QC 4x4. I was idling down a steep driveway and when I got to the bottom I was mashing a hard brake pedal and still rolling. If a car had been coming down the street I would have likely rolled right out in front of him!

Truck is a 2017 Hemi QC 4x4. Only has 4000 miles on it.

Driveway was very steep but was clean and dry and around 55F. I heard no tires sliding and no ABS light or chime. Truck was in 2H DRIVE at the time and idling - brakes should have held it.

Never felt this before and everything seemed normal afterwards (truck stops fine). I wasn't able to repeat it as my family was with me and I didn't want to alarm them.

Needless to say this was a little concerning! What could have caused this? I'm thinking something in the ABS system was kicking in but if that's the case it's NOT good!

Abs does not work below certain speed. Usually 5mpH.

 

[John-e-racer]

I have experienced this with a well worn master cylinder.

Light braking followed by harder braking seemed to let the fluid by the seals, the peddle would go almost to the floor and stopping was difficult, otherwise braking was normal.

I am betting you have a bad master cylinder. Your truck has too low a miles for it to be worn obviously but it could definitely be faulty.

Not likely. Cold tires and no abs at low speed.

 

[Craig Muszynski]

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