Rear brake pad replacement — EPB and piston tool

Tags: #parking-brake · #part-number · #conflict

Core mechanical fact — the rear caliper piston is threaded, not push-in. Unlike a typical front caliper, the rear brake piston sits on a worm/threaded shaft ("червячный вал") and cannot be pressed/pushed in like a conventional piston — it must be screwed in (rotated) to retract. Using a standard push-type piston compression tool will not work and risks damaging the piston if forced. This mechanical detail is the reason the whole procedure below differs from a typical front-pad job.^12345678

Piston retraction tool. A dedicated tool with a screw-in spindle (not a push-type spreader) is required to rotate the piston fully home. A confirmed working tool is available on OZON, product code 2413649314. Reported improvised alternatives that also work by applying rotational torque: a gas-pipe wrench or an angle-grinder spindle-lock key, applied horizontally to the worm shaft.^12345678

Do you actually need a diagnostic scanner to release the parking brake motor? (2026-08 report). Before attempting a DIY rear-pad job, Маksim questioned why he'd been told a diagnostic scanner ("компьютер") is needed to put the electric parking brake into service mode, when a simple button/ignition manipulation could release it without one.⁹¹⁰ Игорь Игорев replied with a button-and-ignition sequence: hold the parking-brake release button down, turn off the ignition, remove the key while continuing to hold the button — the car is off and the parking brake stays released.¹¹ Марина described a close variant: hold the brake pedal, press the handbrake button down, and — without releasing either — turn off the car, then proceed to pad service.¹² These button/ignition sequences are consistent with the other release procedures already documented above and confirm a diagnostic scanner is not strictly required for this step on many cars.^9101112

DIY alternative — powering the caliper's parking-brake motor directly with 12V (2026-08 report). Маksim separately reported finding a different way to release the caliper when the button/scanner methods aren't available or trusted: disconnect the parking-brake motor's terminal at the caliper and apply 12V directly from the car battery — this drives the motor and spreads the pads apart (equivalent to what the scanner's service-mode command or the button sequence achieves electronically). After installing the new pads, reverse the polarity of the 12V feed to run the motor the other way, which draws the pads back together/closes the caliper.¹³¹⁴ Note this addresses only how to move the parking-brake motor/piston mechanism itself — it does not replace the separate threaded-piston retraction step documented above if the piston also needs to be screwed in. Arсhi 77 pushed back that this was overcomplicated — in his view it's genuinely simpler to just release the parking brake with the button/ignition trick and skip messing with the caliper's motor wiring at all.¹⁵ Василий Егоров reported doing the whole job with the engine left running, taking about 10 minutes.¹⁶ Treat the 12V-direct method as a documented but disputed shortcut — most of the community leans toward the simpler button/ignition release.

Electronic parking brake release procedure — pre-restyle models. To safely release the electric parking brake for pad service: (1) with the ignition ON, shift to N; (2) apply the footbrake; (3) press the parking-brake release button; (4) turn the ignition OFF — the parking brake stays released through this sequence. After replacing the pads, minimize the time before first engine start to avoid triggering BCM adaptation errors.^1718192021

Conflict — restyle models use a different sequence. A separate, later-model ("restyle") procedure was reported: shift to P, turn off ignition, hold the footbrake while releasing the parking brake, then release the brake pedal and remove the key. This is a genuinely different sequence (P instead of N, different hold/release order) from the pre-restyle procedure above — confirm which generation your car is before following either one, since using the wrong sequence risks the parking brake re-engaging mid-service or a BCM error.¹⁷¹⁹

Simplified/alternate restyle-era procedure, second report. A related but slightly different write-up: engage the handbrake button down before shutting off the car; press the brake pedal firmly before opening the caliper; use the screw adjuster (not a piston-push tool, consistent with the threaded-piston note above) to compress the piston; after reassembly, apply the brakes several times before driving to properly seat the new pads; use a scanner to reset the electronic caliper if the car's system requires it.²²²³²⁴

Quick electric-handbrake release (general reference). A simpler community-reported shorthand for releasing the electric handbrake for any wheel/brake service: hold the brake pedal down and press the handbrake button downward.²⁵²⁶

Earliest documented release sequence — a third variant (2024-04 video report, predates both sequences above). An early video walkthrough documents yet another service-mode entry sequence, distinct from both the pre-restyle and restyle procedures above: (1) start the engine with the parking brake applied; (2) press the brake pedal; (3) press and hold a button while continuing to hold the brake pedal; (4) turn the ignition off; (5) remove the key; (6) release the button and the brake pedal. Following this sequence, the parking brake does not re-engage, allowing pad service; the car exits service mode automatically once the brake pad work is complete. Given this predates the other two documented sequences chronologically, treat all three as reflecting either different model years/generations or different valid button-press variants of the same underlying service mode — confirm against your specific car before relying on any single sequence.²⁷

General lubrication procedure, applicable to front or rear pads (2024-06 report). Beyond the rear-specific threaded-piston mechanics above, a proper pad replacement — front or rear — should include: inspecting the caliper cylinder for cleanliness, applying lubricant to the guide pins and under the piston dust cover, and checking pad-to-caliper fit before final installation. Typical job time: 10–15 minutes per side. Community observation: many shops skip the lubrication step, which is cited as a common contributor to future brake squeal/whistle complaints — this is a useful DIY checkpoint even at shops that "just swap pads."²⁸

Media

Video demonstrating rear brake pad replacement steps: handbrake engagement, brake application, caliper adjustment procedure

Early video demonstrating the third service-mode entry sequence for brake pad replacement (button + brake pedal + ignition sequence)

Related pages

• Rear brake pads
• Rear brake pad bore diameter — 133.1mm
• Front brake pads
• Brake caliper repair kits
• Front brake discs

Sources

This page is compiled from 28 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-10-29