If one wheel locks up while the others keep rolling during a normal brake application, you have an imbalance somewhere in the system. Most commonly it's a stuck caliper or a contaminated brake line at that corner. Less commonly it's the ABS module or proportioning valve. Driving this way is risky - a single locked wheel can pull the car hard mid-stop. Here are the most likely causes ranked by frequency.
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A seized piston refuses to release after each brake press, gradually clamping harder. Often paired with the wheel getting hot, a burning smell, and the car pulling toward that side. Parts: $80 - $250. Labor: $150 - $300. Difficulty: Shop.
Get a Free AI Diagnosis →The flexible brake hose can fail internally - fluid goes in but won't come back out, so the caliper stays clamped. Common in older cars. Replace the hose. Parts: $20 - $80. Labor: $100 - $250. Difficulty: Medium DIY.
Get a Free AI Diagnosis →When slide pins corrode or run dry, one side of the caliper drags more than the other, locking the rotor on hard stops. Service and re-grease fixes it. Parts: $5 grease. Labor: $80 - $200. Difficulty: Easy DIY.
Get a Free AI Diagnosis →A faulty wheel-speed sensor or ABS valve can fail to release pressure at one wheel during ABS activation. Usually paired with an ABS warning light. Parts: $40 - $400. Labor: $100 - $300. Difficulty: Shop.
Get a Free AI Diagnosis →On rear-drum/front-disc cars without ABS, the proportioning valve balances front-to-rear pressure. When it fails, one axle gets too much pressure and locks. Parts: $80 - $250. Labor: $100 - $200. Difficulty: Shop.
Get a Free AI Diagnosis →Grease or brake fluid on one pad changes its friction coefficient dramatically - either too grippy or too slick - causing uneven lockup. Replace pads and clean the rotor. Parts: $40 - $150. Labor: $120 - $250. Difficulty: Medium DIY.
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Only at low speeds, and only briefly. A wheel that locks under braking can pull the car hard sideways - dangerous on highways or in panic stops.
A stuck caliper piston, by far. The piston seizes from corrosion, refuses to fully release, and gradually clamps harder with each application.
Caliper replacement: $250 - $500 at one corner. Brake hose: $150 - $300. ABS module: $700 - $1,500. Always includes new pads and possibly a rotor at that corner.
Yes - this is very common in cars over 10 years old. The hose collapses internally, lets pressure in but not back out, and the caliper stays clamped.
Front-left is by far the most common corner for stuck calipers because it tends to see the most heat in left-side-drive traffic. Replace caliper, hose, and pads at that corner.
If the ABS warning light is on and the lockup happens only during hard stops, yes. If the lockup happens on every normal stop, it's mechanical.