Intgrated Brake Controller Bypassed?
Cargo Master
Joined: Jun 2008
Posts: 2,752
Likes: 5
From: Stillwater, OK
I don't know all of the tiny details of the programming, but the two inputs that I would imagine are exclusively necessary to even begin to output to the trailer brakes are 1) the tow vehicle brakes must be applied at least to the minimum (the brake lights activated), or 2) the manual slider must be activated. Either of these should be necessary before the controller outputs any signal to the brakes.
The only other way for the brakes to apply is if the break-away switch is activated.
That is assuming everything is in working order.
My first thought is that the trailer is wired wrong and the brakes are connected to the 12+ line, and thus always fully applied.
The brake switch could be malfunctioning.
The manual slider could be malfunctioning.
The only other way for the brakes to apply is if the break-away switch is activated.
That is assuming everything is in working order.
My first thought is that the trailer is wired wrong and the brakes are connected to the 12+ line, and thus always fully applied.
The brake switch could be malfunctioning.
The manual slider could be malfunctioning.
New User
Joined: May 2015
Posts: 17
Likes: 0
I don't know all of the tiny details of the programming, but the two inputs that I would imagine are exclusively necessary to even begin to output to the trailer brakes are 1) the tow vehicle brakes must be applied at least to the minimum (the brake lights activated), or 2) the manual slider must be activated. Either of these should be necessary before the controller outputs any signal to the brakes.
The only other way for the brakes to apply is if the break-away switch is activated.
That is assuming everything is in working order.
My first thought is that the trailer is wired wrong and the brakes are connected to the 12+ line, and thus always fully applied.
The brake switch could be malfunctioning.
The manual slider could be malfunctioning.
The only other way for the brakes to apply is if the break-away switch is activated.
That is assuming everything is in working order.
My first thought is that the trailer is wired wrong and the brakes are connected to the 12+ line, and thus always fully applied.
The brake switch could be malfunctioning.
The manual slider could be malfunctioning.
Senior User
Joined: Mar 2015
Posts: 475
Likes: 0
From: Yonkers, NY
I saw a truck comparison review somewhere on Youtube where they hooked different trucks to the same trailer and took them down a long hill, like miles long, and then used an infrared heat gun to check the brake rotor temperatures on the trucks and trailers to see how the controllers were stacking up. The trailer wheels were always hotter than the truck wheels. Maybe something to test.
Cargo Master
Joined: Jun 2008
Posts: 2,752
Likes: 5
From: Stillwater, OK
The TBC cannot apply the truck brakes. There is physically no way.
Even an ABS malfunction would not apply more pressure than your foot provides.
The only thought I have is that you have water in your brake lines that is boiling. The increased vapor pressure of the boiling water will seem to apply the brakes. Heat from the applied brakes will then, in turn, add more heat to the moisture and further increase the pressure. The quick remedy for this is to flush the brake system.
Even an ABS malfunction would not apply more pressure than your foot provides.
The only thought I have is that you have water in your brake lines that is boiling. The increased vapor pressure of the boiling water will seem to apply the brakes. Heat from the applied brakes will then, in turn, add more heat to the moisture and further increase the pressure. The quick remedy for this is to flush the brake system.
New User
Joined: May 2015
Posts: 17
Likes: 0
The TBC cannot apply the truck brakes. There is physically no way.
Even an ABS malfunction would not apply more pressure than your foot provides.
The only thought I have is that you have water in your brake lines that is boiling. The increased vapor pressure of the boiling water will seem to apply the brakes. Heat from the applied brakes will then, in turn, add more heat to the moisture and further increase the pressure. The quick remedy for this is to flush the brake system.
Even an ABS malfunction would not apply more pressure than your foot provides.
The only thought I have is that you have water in your brake lines that is boiling. The increased vapor pressure of the boiling water will seem to apply the brakes. Heat from the applied brakes will then, in turn, add more heat to the moisture and further increase the pressure. The quick remedy for this is to flush the brake system.
can an ABS malfunction cause the truck to apply brakes without pressing the pedal and/or not release after the brake pedal is released?
Senior User
Joined: Mar 2015
Posts: 475
Likes: 0
From: Yonkers, NY
Any water in the brake lines is readily absorbed by the brake fluid. With heat it will vaporize into gas, but the main symptom of that is spongy brakes as anything in a gas state does not have hydraulic properties to apply the brakes. The gas, whether air or vapor, will compress without transferring your pedal pressure to the brake pads. Hydraulic fluid won't compress.
Still a good idea to flush brake fluid out and add fresh, but I don't believe its related to your problem.
Edit - Unless you have hydraulics in the trailer. Air or vapor in that system could cause the trailer brakes to be ineffective (spongy) and cause the symptoms you are describing.
Still a good idea to flush brake fluid out and add fresh, but I don't believe its related to your problem.
Edit - Unless you have hydraulics in the trailer. Air or vapor in that system could cause the trailer brakes to be ineffective (spongy) and cause the symptoms you are describing.
Cargo Master
Joined: Jun 2008
Posts: 2,752
Likes: 5
From: Stillwater, OK
ABS does not apply any more pressure than your foot does. It simply releases the pressure with rapid pulses to keep the wheels from locking up when it senses a speed differential between the wheels in a braking event.
Vaporized moisture will create spongy brakes while cool. Once heated, it has the potential to put a pressure on the system... it is the same principal a steam locomotive works on.
As far as not releasing after the pedal is released. That could be sticking slide pins.
Vaporized moisture will create spongy brakes while cool. Once heated, it has the potential to put a pressure on the system... it is the same principal a steam locomotive works on.
As far as not releasing after the pedal is released. That could be sticking slide pins.
Thread
Thread Starter
Forum
Replies
Last Post
