In today’s market, a growing number of auto manufacturers are implementing electronic parking brakes into many of their offered models – and not just the luxury ones. This can be a helpful feature that not only cleans-up the look of your footwell or center console, but provides a pre-calculated tension against the rear brakes to hold your vehicle reliably in place when you’ve just finished parallel parking on a near-vertical street in San Francisco. Some of you may be wondering, though, how this might complicate things when you’re ready to service your rear brakes? This mainly depends on the manufacturer of the EPB, and the availability of a capable scan tool (if required) to enter the “service mode”, which most EPBs require before any work can be done on the brake(s) affected. Read on to find out all about the recent uprising in EPBs and the viability for working on them in your own garage.
How electronic parking brakes differ from traditional parking brakes
This answer may seem more obvious than not, however, aside from the parking brakes being actuated via a high-torque motor that engages the brake pads or shoes, there are a couple different types of EPBs and the way they physically engage and disengage the brakes. To explain it simply, an EPB replaces the need to engage a parking brake with your hand or foot. This may be an advantage or disadvantage for some, as many people still enjoy the feel and physically-reassured stability of operating a hand or footbrake (and even frequently use it while at the track – drifting, anyone?). Personal preference aside, some EPBs may even implement a traditional-style cable system to engage the rear brakes, but the only difference is that the hand or foot engagement lever has now been replaced with a cable-tensioning motor. Other types include individual motors at the rear wheels that directly engage the brakes.
Different types of EPBs
Surprisingly, there are only a couple types of electronic parking brakes used among main auto manufacturers, sold by only a few different companies at this time. This is likely subject to change as demand for a defined parking brake future becomes more apparent. Here are the two most common types of EPBs available, and how they operate:
- Caliper-integrated system (most common) – Fortunately, these systems exist, which are much more maintenance friendly. Being mounted at each rear wheel, they are remotely activated by an electronic switch and contain a high-torque motor that engages a screw-type mechanism, pushing against the brake pads which sandwich against the rotor. Repairing these or removing them are relatively easy – just enter maintenance mode and simply unscrew the two or three mounting bolts.
- Cable-pull system – These units are often used by some luxury car manufacturers, and have been known to be mounted in difficult-to-access locations such as above the fuel tank, and blocked by the rear subframe. Not the most easily serviceable electronic parking brakes! They work in conjunction with a traditional parking brake pull-cable system, but are equipped with a high-torque motor to tug on the cable until sufficient tension is applied to the brakes.
The most important step in servicing your rear brakes equipped with an EPB
We’ve mentioned this before, but all electronic parking brake systems require you to enter a “maintenance mode” before they can be serviced. This basically means the parking brake will disengage fully once this is performed, releasing all pressure from the parking brake system to allow the technician to service the brakes (rear brake pad replacement, rotor removal, etc.). If this is not done before you disconnect the battery and possibly go into a deeper job, some manufacturers allow you to manually “screw-in” the engagement mechanism to fully release the braking brake. It’s usually worth it and much less of a headache to enter maintenance mode beforehand, though. Keep in mind that entering this mode can be different across multiple manufacturers. It is not like OBD II systems where this is standardized – some automakers require a special scan tool capable of performing this, and others might simply provide this function through accessing some submenus on the dash.
Another important step is to unplug the parking brake module’s electrical connector once maintenance mode has been entered – this will prevent damage to the braking system being worked on, as well as any serious personal injuries!
After-service wrap up
Once you’ve finished all work on the braking system and everything is assembled, make sure to revert back from entering maintenance mode by whichever method you used to enter it. If you do not, you may lose parking brake functionality until this is done. When you exit maintenance mode, you should hear the parking brake activate and make noise for around 10 seconds or so.
So, long story short – Yes! With the right tools, any home mechanic should be able to service their rear brakes of the future. In time, there may be greater advancements regarding these systems that make them more inviting to being worked on in the home garage.
