Owners consistently report brake failure during low-speed turns—especially when pulling into parking spaces. The brake pedal goes soft or all the way to the floor, forcing drivers to shift into Park or straighten the wheel to stop. This happens intermittently and disappears after a restart, making it nearly impossible for dealers to replicate. The ABS light and "Service Brake Assist" warning light appear together.
Other owners describe complete brake failure at highway speeds or while approaching stops. Several lost 95% of braking capacity due to severely rusted brake lines corroded at junction points. One owner's rear brakes leaked completely dry on an 18-month-old vehicle at 29,462 miles; another had a rear differential seize and lock the brakes. A front caliper locked up, causing extreme heat and a required $1,500 repair.
Brake line corrosion is recurring—one owner had three brake-related failures over seven years including rust holes in hard lines. Early brake pad wear (requiring replacement under 30,000 miles on nearly-new cars) is also reported, with Cadillac attributing it to modern non-asbestos compound but refusing warranty coverage.
Dealers consistently claim they cannot find the problem or replicate it. One independent mechanic traced a "Service Brake Assist" failure to a wiring harness issue between the EBCM and left wheel speed sensor, suggesting possible design defect in some harnesses. GM has issued recall 10V105000 for some vehicles, but the issue recurs in some cases even after recall work.
Failure modes owners describe
Brake system failure while turning at low speed
Brake pedal loses effectiveness or goes to the floor when vehicle turns sharply at low speeds (typically <5 MPH while parking or turning into parking spaces). ABS and 'Service Brake Assist' warnings commonly appear. Vehicle requires shifting to Park to stop, or owner must pump brakes hard or straighten wheels to regain stopping power.
When: Primarily reported between 8,000 and 120,000 miles; some owner reports as early as 18-29,000 miles
Symptoms owners cite: Brake pedal travels to floor or loses pressure during left/right turns at low speed; ABS light illuminates; Service Brake Assist warning message on dashboard; Traction control light comes on; Loss of brake assist feel in pedal; Problem occurs intermittently; disappears after engine restart
Codes mentioned: Service Brake Assist warning, ABS light, Traction control light
Repairs/costs cited: Dealers consistently report inability to replicate issue during diagnostic. Multiple owners report attempted repairs including brake pad replacement (unnecessary when pads had 50% life remaining), wheel speed sensor wiring harness rerouting away from inductive voltage sources (one forum contributor's successful repair), EBCM replacement, and brake caliper replacement. Owner reports Cadillac recall 10V105000 applied to some but issue sometimes recurred afterward.
Recalls/TSBs owners mention: NHTSA Campaign 10V105000 (Service Brakes, Hydraulic); Cadillac Recall #09149; Some claims that GM has not acknowledged the design issue or issued TSB. One dealership employee anecdotally stated he has seen this problem 'more than once' and suggested it stems from failure in wiring harness design/workmanship connecting EBCM to speed sensors.
Brake line corrosion and rupture
Brake lines develop rust and corrode, leading to fluid leaks and partial or complete loss of braking. Failure occurs in hard lines, particularly at ABS distribution block connections or near fuel filter location. Some lines develop holes from corrosion.
When: Reported at 110,000+ miles; at least one instance at unknown mileage but owner noted 7-year intervals between failures
Symptoms owners cite: Brake fluid leak (small puddle under vehicle); Brake pedal moves closer to floor with reduced feel; Complete loss of braking in severe cases; Check brake fluid level warning indicator illuminates; Service Brake Assist warning message
Codes mentioned: Check brake fluid level warning
Repairs/costs cited: Brake lines repaired by splicing in new sections. One owner reported $208 repair plus tow; another $187 repair with splicing to both lines. One corrosion failure noted hole on top side of front passenger brake line on hard line between ABS distribution block and caliper connection.
Recalls/TSBs owners mention: NHTSA Campaign 10V105000 referenced in some complaints but vehicle VINs reported as not included. One owner noted earlier GM recall for front-end rust corrosion (unspecified campaign number) but new brake line failure occurred afterward.
Locked or sticky brake caliper
One front brake caliper locks up on driver's side, causing dragging, excessive heat, and burning smell. Pedal becomes loose and close to floor.
When: Reported at unspecified mileage
Symptoms owners cite: Brake noise when applying brakes during turns; Burning smell from brakes after driving; Brake pedal feels loose and close to floor; Rim on affected side very hot after operation
Repairs/costs cited: Left front caliper and brake hoses replaced at cost of $1,500 by dealership.
Recalls/TSBs owners mention: Dealer stated no recalls on vehicle at time of repair; however, owner later discovered 2010 recall existed (specific recall number not stated in narrative).
ABS system component failure
ABS wheel assembly or related sensor/hub components fail, causing intermittent brake loss during slow-speed turns. Problem may recur even after replacement of failed components.
When: Reported at early mileage (6 months old) and recurring later
Symptoms owners cite: Car shudders when turning sharply and braking at low speed; Brake assist feeling absent; ABS light illuminates; Check brake assist warning appears; Problem intermittent; resets after engine off/restart
Codes mentioned: ABS warning light, Check brake assist warning
Repairs/costs cited: ABS system assembly in wheel replaced. Issue recurred after replacement, suggesting underlying cause not addressed by component swap alone.
Recalls/TSBs owners mention: No manufacturer response documented; owner notes Cadillac does not acknowledge design flaw.
Rear differential lock-up
Rear differential assembly freezes or seizes during operation, locking rear brakes and creating safety hazard.
When: Reported at unspecified mileage
Symptoms owners cite: Squealing noise (initially thought to be emergency brake); Sudden rear brake lock-up while driving
Repairs/costs cited: Rear differential assembly replaced.
Recalls/TSBs owners mention: GM offered 12 months free oil change, tire rotation, and inspection as compensation; owner declined.
Premature brake pad wear
Brake pads require replacement at very low mileage (under 30,000 miles), with dealership claiming this is normal wear due to modern non-asbestos pad composition.
When: Reported at 18–29,000 miles on new/near-new vehicles
Symptoms owners cite: Brake alert light illuminates
Repairs/costs cited: New brake pads and possible rotor replacement required.
Recalls/TSBs owners mention: Cadillac response explains modern brake pad composition contains no asbestos and uses softer materials balanced with metallic materials, acknowledging 'trade off might be shorter pad life, depending on braking usage and conditions.' Brake pad and rotor replacement stated as not covered under manufacturer warranty and considered maintenance item, not defect.
Synthesized from 48 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.