COMPLETE BRAKE FAILURE-Definate Electrical

[SANDRA WILLSON]

I realize brakes have been discussed, and talk of the ABS being the problem. My problem goes a bit deeper, complete brake failure. I had been having problems with the brakes for a while, and was going to change them. My issue became serious when I was pulling my 35' Weekend Warrior Toy Hauler and 1/2 mile from my destination the pedaal hit the floor and I was forced to use my E-brake.
I decided to replace new Rotars, Calipers and brakes and lines on all 4, but attempting to bleed I still had nothing. When engine off, I would feel some pressure, but not near what I should. The moment I turn on the pedal hits the floor.
This is electrical and I'm hoping to get some advice on the module it could be. I have been told ABS, yet there are more than this and I don't want to buy module after module chasing down the issue. The are all over $300.
So any thoughts, and is there a way to test each module before removing. There were some brake related recalls, but the dealer assured me none would cause total failure. Dealership couldn't fix the recalls without the brakes working so I'll have to take it back once fixed.
Help! Please

 

[SANDRA WILLSON]

I realize brakes have been discussed, and talk of the ABS being the problem. My problem goes a bit deeper, complete brake failure. I had been having problems with the brakes for a while, and was going to change them. My issue became serious when I was pulling my 35' Weekend Warrior Toy Hauler and 1/2 mile from my destination the pedaal hit the floor and I was forced to use my E-brake.
I decided to replace new Rotars, Calipers and brakes and lines on all 4, but attempting to bleed I still had nothing. When engine off, I would feel some pressure, but not near what I should. The moment I turn on the pedal hits the floor.
This is electrical and I'm hoping to get some advice on the module it could be. I have been told ABS, yet there are more than this and I don't want to buy module after module chasing down the issue. The are all over $300.
So any thoughts, and is there a way to test each module before removing. There were some brake related recalls, but the dealer assured me none would cause total failure. Dealership couldn't fix the recalls without the brakes working so I'll have to take it back once fixed.
Help! Please

2017 RAM 2500 6.7 LARAMIE

 

[crash68]

You probably need to bleed the ABS module, you'll need AlfaOBD or similar to activate the ABS Bleed function.

 

[04fxdwgi]

Pedal hitting floor like that sure sounds like a hydraulic failure. Blown MC or a blown line maybe. Have you seen any oil on the ground?
If not I would be certainly paying some attention to the Master Cyl.

Things changing when truck starts could be because now you have high pressure from the pump running now.

 

[Hagar1]

Pedal hitting floor like that sure sounds like a hydraulic failure. Blown MC or a blown line maybe. Have you seen any oil on the ground?
If not I would be certainly paying some attention to the Master Cyl.

Things changing when truck starts could be because now you have high pressure from the pump running now.

I prefer to NOT call it "oil" because it confuses some folk. It is generally referred to as "fluid" in this case "Brake Fluid"
The concern is that when someone sees "oil" they may reach for the 10w30 can. ..... I've seen it happen.

 

[PolarisCobra]

In my experience, when the pedal goes to the floor, it is either a large leak (should be easy to find, and if the fluid in the master cylinder reservoir is full, it isn't a leak), or a failed master cylinder. Since the ABS module is right after the master cylinder, it is possible that air was pumped into the ABS module. Most of us don't have the tools to properly bleed that, probably best to get it to a shop that can do it.

 

[Ken226]

I decided to replace new Rotars, Calipers and brakes and lines on all 4, but attempting to bleed I still had nothing.

So, definitely not electrical.

You got air into the ABS hydraulic control unit and will need to bleed it.

Any bidirectional scan tool can do it, or AlfaOBD.

 

[tjfdesmo]

HDs have a hydroboost setup that runs off the power steering pump, so there is oil involved in operation.

 

[Hagar1]

HDs have a hydroboost setup that runs off the power steering pump, so there is oil involved in operation.

Indeed there is but it is entirely separate from the brake fluid reservoir. All the oil could be gone from the hydroboost but it won't cause the pedal to go to the floor. Mechanically, it might be one big lump but essentially 2 different systems.

 

[tjfdesmo]

Indeed there is but it is entirely separate from the brake fluid reservoir. All the oil could be gone from the hydroboost but it won't cause the pedal to go to the floor. Mechanically, it might be one big lump but essentially 2 different systems.

Understood. Wasn't saying it was the cause, just that there can be an oil leak related to the system. I have owned hydroboost trucks since 1982, and mediums with hydrovac before that.

 

[jws123]

I would for sure be looking at your master cylinder ect.

 

[Hagar1]

I would for sure be looking at your master cylinder ect.

Yes, if the primary cup failed it could cause a low pedal but to have t primary cup fail on both pistons would involve astronomical odds.

 

[SANDRA WILLSON]

Pedal hitting floor like that sure sounds like a hydraulic failure. Blown MC or a blown line maybe. Have you seen any oil on the ground?
If not I would be certainly paying some attention to the Master Cyl.

Things changing when truck starts could be because now you have high pressure from the pump running now.

No oil on the ground, Master cylinder is not leaking at all. I will check further. Could this be as simple as a fuse? Sorry for delay in my response, I appreciate the feedback.

 

[Snapper 60]

G'Day Sandra,
I haven't gone through all the replies yet but here is your solution, Diesel 2500 have Hydro Boost braking system and hence you bleed it via the Power Steering.
This is what you are to do Jack the front tyre off the ground both, turn the ignition to RUN (DO NOT START THE ENGINE). (STEP 1)turn the Steering Wheel from Left to Right 7 times and (STEP 2)then pump the Brake pedal 3 times, you keep doing this until you have the brake pedal back up with feel. You may need to do this 20 time or 99 times until it works.
Now the important part when yo believe you have it done, someone must watch the Power Steering fluid when you start the engine, if it FALLS AT ALL, turn the engine off for and don't restart bleeding for 45 minutes the repeat step 1 & 2.
This should take about an hour ok and it will work believe me I had to tell the RAM Dealer who to do it.

 

[Marshall]

No oil on the ground, Master cylinder is not leaking at all. I will check further. Could this be as simple as a fuse? Sorry for delay in my response, I appreciate the feedback.

If you think this is electrical, you do not understand the system. Tossing new rotors will not fix it, and if you don't have brake fluid on the ground at any of the wheel, you likely have lots of air in the system, or master cylinder seals shot.

Codes will have nothing to do with brake peddle on the floor.
Sometimes you just have to pay a shop to fix stuff .

I am not much help on ABS systems, there are a couple posts on that.
BTW you said you changed the pads and rotors? what did they look like when you pulled them out?