Could this be another ABS problems on a Ram?

[LR Boe]

Hi Fella's,
I have a 2018 Ram reg cab short bed with a V6. 27,000 miles on the clock, Nice truck. Only one problem.
The problem I have is the truck will randomly apply the front brakes anytime it wants. When it happens, The front end starts vibrating until I pull off on the shoulder of the road. The only way I can get the brakes to release is to disconnect the negative side of the battery to 20 minutes or so then I can continue on. Its been doing it for about a little over a year now. No lights in the dash are on when it happens, No codes when scanned. I called Chrysler Corp and the dealer I bought it from new. Both reps. told me I'm the only one they've heard about having this issue. Yeah Sure! ! I'm thinking the ABS module or the HCU pump may be the issue . With no codes or faults showing on the scan tool at the Ram dealership. Where do you start? I don't want to just start throwing parts at it hoping it fixes the problem at some point. It's so intermittent It'll be awhile before I even know the issue is resolved if I start changing parts. Any suggestions based on issues you guys have had? Thanks in advance guys.

 

[62Blazer]

Are you sure it's actually the brakes applying? Does it act the same as if you were running down the road and actually applied the brakes? Once you come to a stop does it acts like the brakes are stuck on, and if you try to take off driving again it starts to immediately vibrate?

 

[LR Boe]

Yes It does apply the front brakes only. I can pull off the road and feel the heat coming off both front wheels when I touch the rims. No heat on the back wheels. If I put in Drive to pull off you have to depress the gas quite a bit to get it moving and as soon as you let off the truck stops. The last time it did it I had the cruise control on about 54mph. (Does it either way cruise on or off) I heard the transmission down shift and the rpm went up on the tach. I turn off the cruise control and the truck immediately had a hard dragging feeling. Of course I knew what it was the brakes because its done it many times before.

When it first started applying the brakes by itself it would ONLY do it when I drove by a small municipal Airport we have about 30 miles from home. But only on the trip back home.
Having an Electronics Engineering background by trade ( retired now) I intially thought it was RF signal interference activating the front brake. But now its happened in two or three other areas away from the airport.
As I said, The only way to release the front brakes is to pull the neg. battery cable off for about 20 minutes. Which at least tells me its electronic related. But which module is being reset that's causing the issue? After I reset it one time that day, It'll never do it again on the same day. I might drive it on a multiple trips to town on different days and it won't act up. Its just random. Again, No light in the dash and no fault codes ever. The electronics on the truck does not recognize that there's a problem. A helpful diagnostic function would be if you could disable one function at a time on the truck. Then you could isolate the issues very quickly.

 

[RamInfo]

Consider me crazy, but I’d be crawling underneath to see if any brake lines have been crimped or bent, causing an obstruction that is not allowing fluid to return to the hydraulic brake system after the brake is released. The dragging brake builds up heat, fluid expands and begins to apply pressure on its own. This can happen from a bent/kinked/crushed steel line or a rubber line that has degraded or separated inside. A degraded rubber line will often show flecks of material in the fluid when bled out.

Your 20min battery disconnect may be doing nothing more than allowing things to cool down…

best,
DG

 

[LR Boe]

Raminfo,
Thanks for the input, I have inspected all the lines and calipers. I thought about the rubber hoses but it applies brakes on both front wheels when it happens not just one side. I thought it might be something as simple as a sticky piston in the master cylinder. Since there were no codes being recorded. So, I replaced it. Drove it a couple times, Same problem. The worst problem you can have with any electronic device is an intermittent issue. You'll won't know when you have it fixed. I thought about the cooling down senerio, the first time it happened I had my son come pick me up with my other truck and car trailer. That took about an hour and a half or so. Brakes were still dragging when I put it on the trailer.
Another thing
I did the last time, when the brakes started to drag I pulled over and cracked the line to the front brakes on the master cylinder to let off the pressure. I got back in the truck drove about 1\4 mile they started dragging again . I disconnect the neg. post for 20 mins. and didn't have any issues the rest of the day. Go figure. I know, None of this makes sense. I own two other Dodge trucks now a 1996 ,2500 4x4 and a 1999 1500 4x4 not many electronic devices on either. Other than maintenance I have no issues. I think we have too many Engineers building vehicles that don't know how to work on them their selves. How can you build a truck if you don't know how to work on it? Looks good on paper, Not so much in reality. From my 20 plus years in the electronics industry its been my experience the more crap you add on to any electronic device the more failure prone it becomes. Maybe at least one company has seen the light. Ford just announced they are going to make 2024 F150s with 2,400 less parts than the 2023 F150s. Finally, Maybe companies will start making REAL trucks again!

 

[Atcer2018]

I had the same thing happen back in the 90’s on an Olds Cutlass. The front brakes would intermittently lock up and after a period of cool down time would function normally again. The car had a far simpler ABS system than our trucks do. It wasn’t the ABS system on the olds, it was the master cylinder. Stumped me because I assumed with ABS the brakes wouldn’t lock up but being an early system that wasn’t the case.

 

[Daw14]

I suspect bad calipers ,had both my fronts start dragging with under 20,000 miles .

 

[RamInfo]

Last thought, then I’m stumped. Possibly a clogged return port on the master cylinder?

best,
DG

 

[LR Boe]

Dont feel bad I'm stumped too! LOL I installed a new brake master cylinder last week . Started dragging the front brakes again. I called RamCare they ran it by their "So Called". Engineers, They told me it would be codes or dash lights on
if there were a problem with the brakes. This goes back to my theory of guys that are allowed to design vehicles but the only thing they know about the vehicle is where the key goes and where the gas hole is. So much for Ram customer service

 

[LR Boe]

Daw14,
When you had the issue, how were you able to isolate the calipers as the culprit? And did both your front calipers fail at the same time on both sides every time you had the issue? I'm willing to try anything now. My truck had 27,700 miles on it

 

[jimmyfjk]

next time it happens, take images, take videos, get a heat measuring device and capture the heat from the front rotors and the rear. Anything and everything you can capture on video and images. then show this to the service people. if you get nowhere call crysler and tell them you have video and images of it happening.

 

[dpinvidic]

This certainly sounds like a Electronics problem with the ABS system. you should really get a high-end diagnostic scan tool that can read sensor inputs.
With what you explain, you're simply driving down the road not applying the brakes and then all of a sudden ABS activates. It could be something as simple as a wheel sensor going bad making the computer think the wheel is slipping like being on ice.
The important thing is to try to get a scan tool and see what inputs are causing the ABS to do what it's doing

 

[LR Boe]

I have had my neighbor thats the senior tech at the local Ram dealership take a look at it. He brought his Factory scan tools home with him on three different days in a 3 month span. He checked everything in the ABS, and all the related components, Everything that he thought would be related to the issue I have. Nothing has shown up as being wrong. No active codes no recorded codes throughout the trucks history. He even checked the doors switches, he said they have had problems with the door switches being intermittent. The truck thinks the door is open and slows the truck down and switches the transmission into park. I've never had the truck go in to park. Then he drove it to work multiple times with his scan tool running. Finally on the way home he felt the brakes applying. He said he stopped and ran a diagnostics on the truck. Nothing. He called the group that the techs call for unexplained problems like I have. He said they suggested a few things to check that he'd already diagnosed. My neighbor told me they wanted to start throwing parts at it at my expense until they could get the problem resolved. He advised against that approach. I agreed. I suggested the if those Engineering Dumbbells would design diagnostic programs that would disabled one fuction at the time you could at least isolate the area the problems originated. He indicated that would make his life alot easier at the dealership. He'd be able to isolate unexplained issues very quickly. Maybe I should design one and patented it ! I'm still not convinced its not RF interference. No one can prove its not.

 

[jagman_xjs]

Almost lost my RAM due to a caliper on the right rear . A fellow was nice enough to holler at me and let me know it was glowing and smoking. I carry bottled water with me so I used it to cool it down it was smoking EXTREMELY bad. It would not have taken a lot more . The fronts did the same but I could smell them and got them cooled down by just stopping for a bit. Oddly the left rear was never a problem.

 

[LR Boe]

Jagman,
Did both the front calipers go out at the same time?

 

[dpinvidic]

I have had my neighbor thats the senior tech at the local Ram dealership take a look at it. He brought his Factory scan tools home with him on three different days in a 3 month span. He checked everything in the ABS, and all the related components, Everything that he thought would be related to the issue I have. Nothing has shown up as being wrong. No active codes no recorded codes throughout the trucks history. He even checked the doors switches, he said they have had problems with the door switches being intermittent. The truck thinks the door is open and slows the truck down and switches the transmission into park. I've never had the truck go in to park. Then he drove it to work multiple times with his scan tool running. Finally on the way home he felt the brakes applying. He said he stopped and ran a diagnostics on the truck. Nothing. He called the group that the techs call for unexplained problems like I have. He said they suggested a few things to check that he'd already diagnosed. My neighbor told me they wanted to start throwing parts at it at my expense until they could get the problem resolved. He advised against that approach. I agreed. I suggested the if those Engineering Dumbbells would design diagnostic programs that would disabled one fuction at the time you could at least isolate the area the problems originated. He indicated that would make his life alot easier at the dealership. He'd be able to isolate unexplained issues very quickly. Maybe I should design one and patented it ! I'm still not convinced its not RF interference. No one can prove its not.

Did your neighbor experience the EXACT same symptoms as you when it failed? Did your Neighbor need to disconnect the battery to reset the ABS?
I think it is important to run a scan tool when the ABS system is "Locked Up", this is before your reset it by disconnecting the power.
I think it is a electronics problem coupled with something intermittent. RFI noise is unlikely in less it happens every time you drive by a radio tower or some other RF source.

 

[62Blazer]

If it is an electronic signal causing the brakes to engage than it would be the stability control system. Stability control systems can engage individual brakes to help counteract yaw angles and other aspects of the vehicle to keep it under control during a hard maneuver. I'm not sure what in the program of the ABS would actually cause brakes to apply....ABS is trying to prevent lock-up of the tires and will dump brake pedal pressure, not increase it. Now granted, ABS and stability control systems can use the same physical components but point being I would like at the stability control data fields and wiring schematics. A factory scan tool or good aftermarket tool should be able to look at the individual wheel speed sensors and yaw rate sensor to see what is going on. Those may have nothing to do with the problem but would be worth at least looking at the data. Does the truck have any forward collision sensors or anything like that? Just not 100% on a 2018....however will say we have two newer vehicles with that technology but there will be some sort of beep or message appear on the dash also if it activates.
Speaking of the above, I suppose you could try turning off the stability and traction control via the dash switch and see if the issue comes back.

 

[Marshall]

rust in the calipers and they aren't retracting, but that is just a guess, don't sound like it.
have you really looked that the pads and such? Mine will have a hard peddle on start up if it sits in the garage for a few days, 80km on it, works fine.
Maybe a fluid flush?

 

[LR Boe]

dpinvindic,
My neighbor experienced the exact same issue I had explained to him. He had his scan tool on the truck while he was driving to and from his workplace. He felt the brakes applying, he told me he took his foot off the gas and pulled on the shoulder of the road. He indicated he ran the diagnostics on the truck on all the systems. No codes, nothing was recorded that would indicate the event happened. After running all the tests he finally disconnected the battery let the system reset and drove it back to my house.

With almost 30 years of electronics experience , One thing I learned early in my career was when electronic components that change values or you have a thermal runaway condition you will experience unusual and unpredictable problems. Voltage change, resistance change, capacitance change etc. ANY of these problems I have are a possibilty. Problems that don't make sense and are very difficult to isolate.
The majority of electronics are made outside of the U.S. (china) with little or no R. and D . and No Q.C. It doesn't surprise me I have these problems.

And yes, the brakes are applying in the same location 99% of the time. Near an Airport and a Industrial building that I am confident has a security system around the perimeter. Either could be generating RF that could effect the truck. It has only had an issue two times in another location out of about 12-15 events. My believe is I have a outside frequency with a shortwave length causing my issues. This is purely speculation at this point until it can be proven otherwise.

 

[LR Boe]

Marshall,
As a matter of fact we did flush the brake system. Still had the problem. Thanks for you suggestion