Donzi26zx said:
.......
The dealership assumes since I split the calipers that is what caused the problem, ......
I'm intrigued by their assumption. It sounds a very unlikely cause. Can you get them to explain exactly why splitting the front calipers would cause
all 4 brakes to lock on simultaneously.
Imperfect reassembly could possibly cause a fluid leak but you say the reservoir was full so we can rule that out. The other possibility is a slight misalignment of the caliper halves. But how could this cause the whole system to lock over a month later, maybe one of the fronts but surely not the whole system simultaneously?
You don't say whether you were braking when the dash lights came on but to me your post reads like you were simply cruising along and the brakes applied themselves? The dealer can obtain this information from your vehicle. The following is from the owners manual.
DATA RECORDING
Service data recorders in your vehicle are capable of collecting and storing diagnostic information about your vehicle. This potentially includes information about the performance or status of various systems and modules in the vehicle such as engine, throttle, steering or brakes.
In order to properly diagnose and service your vehicle, Land Rover or other service and repair facilities may access vehicle diagnostic information through a direct connection to your vehicle.
Event data recorders are capable of collecting and storing data during a crash or near-crash event. The recorded information may assist in the investigation of such an event. The modules may record information about both the vehicle and the occupants, potentially including information such as:
• How various systems in your vehicle were operating.
• Whether or not the driver and passenger seat belts were buckled.
• How far, if at all, the driver was depressing the accelerator and/or the brake pedal.
• How fast the vehicle was travelling.
• Where the driver was positioning the steering wheel.
IMHO a far more likely possibility is an electrical failure of the Emergency Brake Assist (EBA)function whereby continuous and maximum braking has been applied for some reason. I'd be pursuing this as the cause. Description from RAVE below.
Emergency Brake Assist (EBA)
The EBA is designed to enhance the braking control of the DSC for the driver of the vehicle. The EBA includes two
functions that are programmed into the control electronics of the ABS ECU with no additional hardware changes.
The first EBA function is designed to provide the maximum braking force available during rapid (panic) braking
situations. The ABS control module looks at the inputs from the brake pedal switch and the signal from the brake
pressure sensor on the master cylinder. The criteria for activation of EBA is the speed at which brake pressure builds
up with the brake pedal depressed. The total criteria required for EBA activation includes:
l Brake switch ON
l Brake pressure build up >threshold value
l Vehicle road speed >5mph (8 km/h)
l Vehicle not in reverse
l Not all wheels in ABS operation.
If the threshold for EBA activation is achieved, the ABS control module will activate a pressure build up regulation
phase through the hydraulic unit. The pressure at all wheels is increased up to the ABS operation point. This occurs
even if the driver does not achieve the ABS operation point with the pedal.
The front and rear axle brakes are controlled individually. ABS operation will continue until the driver releases the
pedal and the pressure in the master cylinder drops below the threshold value stored in the ABS ECU.
The second EBA function is also designed to enhance a driver initiated braking procedure. The EBA will build up the
pressure in the rear brake circuit when the front brakes are already in an ABS regulation cycle. The additional braking
pressure at the rear wheels will shorten the stopping distance. The following criteria must be met before the ABS
control module will activate EBA:
l Both front wheel brakes in ABS operation
l Vehicle speed >5mph (8km/h)
l Vehicle not in reverse
l EBA and pressure sensor initialisation test OK
l Rear wheels not in ABS operation.
EBA sensitivity can be adjusted using TestBook/T4. There are three sensitivity settings, default is the most sensitive.
I suspect that the dealer has not pinpointed the real cause and is suggesting that apart from the overheated components, the master cylinder needs to be replaced because that is more likely where the fault originated.
Let us know how you go.
