The workflow described here may vary depending on the lorry type. The figures shown in the guide are there to offer a much better understanding and do not highlight elements particular to a specific lorry.
electrical park brake
Prior to beginning repair work, examine that all the parts of the brake system that you will not be changing are in perfect working order. These include the brake hoses and pipelines, the condition of the brake fluid (boiling point), the seals and pistons of the brake caliper, the guide bolts on the brake provider along with the wheel hub and wheel bearings.
electric park brake
For expert repair, upkeep and diagnostic deal with the electric parking brake, an electronic diagnostic instrument should be readily available that can be connected to the vehicle through the On-Board-Diagnosis (OBD). Before replacing a component of the electrical park brake, the system must be brought into the upkeep mode with the help of this diagnostic gadget. To do this, the controller turns the spindle (Fig. 1), so that the pressure nut can be driven back to its starting position (Fig. 2). After the repair work is completed, the system needs to be calibrated.
2. Elements of the Electric Park Brake 2.1 Brake Caliper
electric park brake
The caliper of the electrical park brake is a one-piston fist caliper of the “Colette” type. The hydraulic function is the same, despite whether the caliper is without parking brake, or has a mechanical parking brake
2.2 Actuator electric park brake
The electric motor drives the actuating transmission by means of a toothed belt. Transmission and spindle are connected together utilizing a Torx ® at the gearbox output.
2.3 Piston, Spindle and Pressure Nut electric park brake
The spindle is connected to the pressure nut by a self-locking thread. The pressure nut is secured against rotating in the piston due to its shape and the matching flat portion in the within the piston. A soon as the spindle is rotated by the transmission in the actuator, the pressure nut presses the piston and, with it, the brake pad versus the brake disc– the brake is activated. In the reverse direction, the brake is launched by the deformation of the piston seal ring (rollback).
2.4 Gearbox electric park brake.
Swash Plate Transmission In the first generation of actuators, a single-stage swash plate transmission assumed the job of activating the parking brake. With a clamping force of approximately 19kN for an overall ratio of ~ 150:1, it satisfies the requirements of the parking brake on the majority of production automobiles.
electric park brake Planetary Transmission The two-stage, planetary transmission incorporated in the actuator, transforms the rotary motion of the motor through the toothed belt with an overall gear ratio of ~ 120:1 into a securing force of approximately 25kN. These high clamping forces are needed to satisfy the requirements of the parking brake for heavy lorries.
3. Replacement 3.1 Housing-Actuator System
electrical park brake
Prior to replacing the housing-actuator system, the system should be brought into the maintenance mode with the help of a diagnostic device.
3.1.1 Eliminate the Connector electrical park brake
Reverse the locking of the adapter with an appropriate tool, and pull off the connector from the actuator.
KEEP IN MIND: Some electric park brake systems use actuators with an integral cable. In this case, the plug connection must be disconnected on the cable harness of the vehicle. This is located, as a rule, in the pertinent wheel real estate!
3.1.2 Remove the Brake Hose/Pipe electric park brake
Get rid of the brake hose/pipe and close completion with an ideal plug to prevent brake fluid going out and clearing the system.
ATTENTION: Brake fluid dissolves paint and is a threat to health. It is necessary to observe the safety instructions from the manufacturer when dealing with brake fluid.
3.1.3 Remove the Dealing with Bolts electrical park brake
Loosen and eliminate both repairing bolts of the brake real estate. During this and depending upon the design of brake caliper, the guide pins on the brake provider must be held fixed utilizing an ideal tool.
3.1.4 Remove the Housing electric park brake
The housing-actuator system can now be managed the brake carrier in the direction of the arrow.
Setup occurs in the reverse order. electric park brake
KEEP IN MIND: Pre-filled housings are fitted with a plug at the connection to the brake hose/pipe. This need to be eliminated before the brake line is connected once again!
Bleed the air from the brake system!
electric park brake
As soon as installed, the system needs to be adjusted using the diagnostic gadget. Follow the directions from the automobile producer in this regard.
3.2 Brake Carrier electric park brake
Prior to replacement of the provider, the system should be brought into the upkeep mode with the help of a diagnostic gadget.
3.2.1 Remove the Brake Housing electric park brake
Loosen and get rid of both repairing bolts of the brake real estate. During this and depending on the design of brake caliper, the guide pins on the brake carrier need to be held fixed using an ideal tool.The housing, including the actuator, can now be managed the brake carrier in the direction of the arrow.
electrical park brake KEEP IN MIND: Fix the real estate so that the brake hose/ brake pipe and cable of the actuator connector are not harmed.
3.2.2 Remove the Brake Pads electric park brake
Get rid of the brake pads and pad retaining springs from the brake carrier.
NOTE: The precise treatment and unique directions for altering the brake pads are explained in Area 3.3.
3.2.3 Remove the Brake Provider electric park brake
Loosen up and get rid of both fixing bolts holding the brake provider to the guiding knuckle. The brake carrier can now be removed from the guiding knuckle.
Setup occurs in the reverse order.
NOTE: Observe the maker info in terms of torques and using thread-locking methods for bolts.
electrical park brake When set up, the system must be calibrated using the diagnostic device. Follow the guidelines from the vehicle maker in this respect.
3.3 Brake Pads electric park brake
electrical park brake
Before replacement of the brake pads, the system should be brought into the maintenance mode “Pad changing” with the help of a diagnostic device.
In this upkeep mode, the controller rotates the spindle (Fig. 1) so that the pressure nut is driven back to its beginning position (Fig. 2). 3.3.1 Remove the Dealing with Bolts electrical park brake
Loosen up and remove both fixing bolts of the brake housing. Throughout this and depending upon the style of brake caliper, the guide pins on the brake carrier need to be held fixed using an ideal tool.
3.3.2 Eliminate the Real estate electric park brake
The real estate, consisting of the actuator, can now be managed the brake carrier in the direction of the arrow.
NOTE: Fix the real estate so that the brake hose/ brake pipe and cable of the actuator port are not damaged.
3.3.3 Get rid of the Pads electrical parking brake
Remove the brake pads and pad retaining springs from the brake carrier.
NOTE: The pad-retaining springs need to always be renewed as they are largely responsible for noise-free operation of the brakes. Ought to the maintaining springs be utilized once again, however, care is definitely necessary to make sure that no deformation occurs during their fitting and removal!
3.3.4 Inspect and Clean the Brake Provider electrical park brake
Prior to putting together the brake, the following parts of the brake provider should be taken a look at:
Guide pins for ease of motion and radial clearance Dust covers for fractures and sealing quality Contact surfaces of the pad maintaining springs or of the pads for damage due to increased rust The brake provider should then be completely cleaned.
3.3.5 Inspect and Clean the Brake Real estate electric park brake
Prior to assembling the brake, the following components of the brake real estate must be taken a look at:
Piston boot for fractures and sealing quality Pistons for ease of movement Real estate for mechanical damage The brake housing need to then be completely cleaned up.
3.3.6 Fitting the Brake Pads electric park brake
Fit the pad-retaining springs and brake pads to the brake carrier.
KEEP IN MIND: Lubricants such as grease or copper paste might not be used unless they are specifically specified! Needs to the pad maintaining springs or the pads jam during the fitting, the brake carrier should be cleaned up again or, in case of doubt, changed. Do not machine the pad or carrier under any circumstances! To ensure ideal performance of the brake system, observe specifically all extra details on the pads, such as pulling off adhesive films or the instructions of installation of the pads! electric park brake Brake pad with recess and information of the fitting direction on the back plate of the pad 3.3.7 Push Back the Brake Piston electric park brake
Before fitting the housing to the brake carrier, the piston should be pushed back to its initial position utilizing a suitable tool.
NOTE: The brake piston in an EPB brake caliper should not be turned back to the start position, in contrast to the practice with mechanical hand brakes. This causes harm to the pressure nut and/or spindle!
3.3.8 Fit Real estate Electric park brake
Insert repairing bolts for the real estate and tighten up to the torque defined by the maker. During this and depending on the style of brake caliper, the guide pins on the brake carrier need to be held repaired using an ideal tool.