# Anti-Lock Brake Repair in Upland > Anti-lock brakes kicking in at slow speed or not at all? Route 66 Auto Repair in Upland finds why and fixes it, with photos and a written estimate. Source: https://route66autorepairshop.com/brake-services/anti-lock-brake-repair Updated: 2026-09-17 Business: Route 66 Auto Repair, 1775 W Foothill Blvd, Upland, CA 91786, (909) 608-7699 Hours: Monday to Friday 8 AM–5 PM, Saturday 8 AM–2 PM, Sunday closed **TLDR:** Anti-lock brakes should stay quiet until **a wheel starts to skid**. False activation and no activation both need a repair and a **verification road test**. Anti-lock brake repair fixes what you feel through the pedal when the system misbehaves: pulsing on dry pavement, a pedal that chatters at a slow stop, or wheels that lock when they should not. Route 66 Auto Repair in Upland finds the cause, repairs it, and road-tests the car to prove your anti-lock brakes act only when they should. ## What should anti-lock brakes feel like? In a hard stop on a slick surface, a working system makes the pedal pulse rapidly and push back against your foot, often with a grinding buzz. That is normal. Keep firm pressure and steer. The system is letting each wheel turn just enough to hold grip. What is not normal: that same pulsing during a gentle stop on dry pavement, at walking pace in a parking lot, or every time you cross a dip on Foothill Blvd. Also not normal: wheels that lock and skid in a panic stop with no pulsing at all. ## Why do anti-lock brakes kick in when they should not? - A weak or erratic signal from one wheel speed sensor, which the module reads as a skid - Rust under a sensor or a cracked tone ring making the signal uneven, fixed with [ABS wheel speed sensor repair](https://route66autorepairshop.com/brake-services/abs-wheel-speed-sensor-repair) - Mismatched tire sizes, or one badly worn tire turning at a different speed - A wheel bearing with too much play, which changes the sensor gap - Worn rear brakes that lock early under light pedal pressure ## Why do tires matter to anti-lock brakes? The system compares wheel speeds, so all four tires need to be close in size. A fresh tire paired with a worn one, or the wrong size on one corner, spins at a different rate and can confuse it. We check tire size and tread depth as part of the diagnosis, and our [tire services](https://route66autorepairshop.com/tire-services) can match tires if that turns out to be the fix. A loose bearing gets a [wheel bearing inspection](https://route66autorepairshop.com/diagnostics-and-inspections/wheel-bearing-inspection) before we point at it. ## Our anti-lock brake repair process 1. **Feel it first:** A technician drives the car to feel the false pulsing or the lockup you described. 2. **Record the data:** Live wheel speeds are logged to find the wheel that reads wrong. 3. **Inspect that corner:** The sensor, ring, bearing and tire at that wheel are checked. 4. **Repair:** The failed part is repaired or replaced to spec. 5. **Prove it:** We repeat the same stops, plus a controlled hard stop where it is safe to do so. ## What's included in anti-lock brake repair - Road test that reproduces the complaint - Logged live wheel speed data - Tire size and tread check at all four corners - Sensor, tone ring and bearing inspection - Repair to specification - Verification road test ## Is it safe to drive? **Need now:** - Wheels that lock and skid in a hard stop - Pulsing that stretches your stopping distance at low speed **Need later:** - An occasional pulse over one rough patch, booked soon - A tire size mismatch you plan to correct at your next tire purchase ## What does anti-lock brake repair cost? It depends on which part is sending the bad signal. A cleaned sensor tip or a new clip is small. A wheel bearing or tone ring is larger. A tire mismatch may just mean matching tires. After testing, you get a written estimate that shows which it is. The diagnostic fee is stated first and applies to the approved related repair. AAA members receive 10% off parts and labor, up to $75. ## Frequently asked questions ### Is it normal for my brake pedal to shake when I stop hard? In a hard stop on a slippery road, yes, that is the anti-lock system working. If it shakes during gentle stops on dry roads, it is either the ABS acting up or uneven rotors, and we can tell which. ### Can mismatched tires really cause ABS problems? Yes. The system compares how fast each wheel spins. A tire of a different size, or one much more worn, turns at a different speed and can make the system think that wheel is slipping. ### Are you on Foothill Blvd between the 10 and the 210? Yes. We are at 1775 W Foothill Blvd in Upland, at Foothill Blvd and Central Ave, one block east of In-N-Out Burger. It is an easy stop if your brakes start acting up on the way home. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.