Brakes Malfunctioning - Turning off.

They actually just figured out how much its gonna be. 14000 total. Like damn. Frames not bent. Most of the front suspension on drivers side is shot. New lca new cv. New other stuff. Ill post a pic of the bill. Turns out the guys who balanced my wheels are idiots. They were all 6-8 oz off balance. But good news i should get my truck back soon. Probly be a month or so until i get em back at the rate these guys seem to get stuff done.

 

I'm still guessing that all the wheels where locked and the trucks speedo read 0. If the truck was sliding down the hill with all the wheels locked, It would assume its not moving. Hence no abs happening cause none of the wheels were turning.

 

I am also not absolutely sure about the brake distribution system. That being said, it would have to be part of the ABS System as that is all that is in place to control the EBD System. Without looking at schematics I would say yes it is also disabled along with ABS.

 

The reason the e brake didn't work very well is that the wheel cylinder collapsed due to the brake line leak. This moves the pivot point on that end of the shoe throwing your brake manual adjustment out the window.

 

$14,000 like in US Dollars. From yoiur original description it didn't sound that bad.... Got any pics?

 

ABS has been around for a long time and was pretty much standard on German cars in the 80's when I was employed by Mercedes so I do know how the systems work you do not need ice to have it operate as you have found out. Just about any heavy aircraft has had ABS for far longer. No matter whose vehicle it is all ABS systems do increase stopping distance on ice and loose sand etc.(if you have a good look at your manual I believe that is stated) the plus side you still have the ability to control the vehicle, on dry pavement they stop better. The ABS is a valving system you do not loose brakes because of the ABS it just increases the stopping distance. In the back of your owners manual is a contact address for the NTSC why don't you just give them a call and see if you get any where?

 

Every time you let off the brake the rear brake shoe springs push the cylinder back in all the way. The parking brake is strictly mechanical if the adjustment is off enough to effect the parking brake your service brakes wont's work worth a damn either.

 

If the master cylinder gave up in such a way that you lost the boost from the PCV system then the brake pedal would not "go to the floor" and you would feel, through the brake pedal, brake pad's trying to grab rotors with little stopping power. At that point throwing the parking brake will just lock the rear with again, little stopping power. No matter what the conditions, a heavy truck rolling downhill will see very little response from applying the parking brake, all the weight and momentum is off the rear.

I have personally experienced sub-par brake response in similar situations off road due to ABS getting involved. When this happens it's very obvious that it is the ABS system as you can feel and hear it working. Did you feel or hear it working?

Now if the master cylinder gave out in such a way that the system was compromised and hydraulic fluid was leaking out and air was leaking in then yeah, the pedal is going to the floor with no response. And again applying the parking brake will not help you once momentum is built.

If you have not done so yet read up on how hydraulic brakes work and how ABS interacts with the system.

Let me ask you this? Where was your right foot when the acceleration began? And is this a 6-speed or Auto? If it was a 6-speed where was your Left foot? Did you see a ABS or Check engine light on the dash before the impact? The shop did the estimate, did they say anything about a failed master cylinder or brake line?

When things get intense the brain shuts off. It sounds like you slid down the hill with 4 locked tires. Did you inspect the tire paths, you can tell, depending on the conditions if they were rolling or skidding. Sorry to hear this happened to you, good luck getting it all worked out!

 

Nah no rental since I'm not old enough for any rental car companies. Yeah insurance is taking care of it minus the deductible.

 

Grand total for me to get my truck back. Turned out to be a pretty major accident after all.

 

All this you claim is from a failed brake system. Yet there has been no mention of them looking into the claimed brake failure????

Or did I miss that part?

 

Yeah, was there any mention from them for why it happened? Or are they just blaming it all on you?

 

It didn't throw a code. They said everything is 100% consistent with what i said happened. They just didn't find a code. But yeah thats from my brakes turning off. 14gs.

And mitchell i had other vehicles i could drive so i didn't really worry about it. hopefully theres never a next time but ill try and get a rental.

 

If the brakes really did just "turn off" you seem to be letting this go way to easy. You hope that it won't happen again? I wouldn't be driving a vehicle that the brakes "turn off" on. But then again brakes don't just turn off. There's solenoids that open and close rapidly (hence the pulsing feeling) to relieve pressure temporarily but not completely. If they did get stuck in the relieve state pumping the brakes would bring the pressure right back up and lock the wheels again. Its not like there's a valve that just can be turned off and the brakes don't work.

https://www.youtube.com/watch?v=rfzuW8wFpgI

I smell fish and sense a case of unintended acceleration....probably had a floor mat below the brake and were pushing the gas.

 

If you were in 4x4 and put on the parking brake(assuming it was adjusted correctly and working), you locked up all 4 wheels. I agree that the abs on these trucks suck in snow and ice, but it has saved my butt a time or two on dry pavement.