A soft or sinking brake pedal, a low brake fluid warning, or a clear-amber puddle near a wheel - those are brake leak symptoms, and this is the one fluid leak that's a true emergency. Brakes can fail completely with little warning. Do not drive. Here's what to do instead.
The most common brake leak source. The piston seal in the caliper fails, dripping fluid onto the inside of the wheel and brake pad. You'll see wet shiny spots on the back of the wheel. $150-400 per caliper.
Diagnose My Leak →Steel brake lines rust and rupture, especially in salt-belt states. A failed line can dump all the fluid in seconds. Repair runs $150-500 depending on which line.
Diagnose My Leak →On the rear of older cars with drum brakes, the wheel cylinder leaks fluid into the drum. You'll see fluid running down the back of the wheel. $100-300 per cylinder.
Diagnose My Leak →The master cylinder pushes fluid through the system. When it leaks externally, look for fluid behind the brake reservoir. When it leaks internally, the pedal slowly sinks while you hold it. $250-500.
Diagnose My Leak →The flexible rubber hose at each wheel can crack or balloon. Less common than caliper leaks but still serious. $100-250 per hose installed.
Diagnose My Leak →Describe what you're seeing and our AI mechanic will tell you what it is, how serious it is, and what it costs to fix - in seconds.
Get My Free Diagnosis →No account needed. First answer is free. Full report is $5.99.
Brake fluid leaks rarely set an OBD2 code, but the brake warning light on your dash is the giveaway. Treat any soft pedal as an emergency.
🔬 Describe Your Leak - Free AI Diagnosis →No. A brake fluid leak can cause complete brake failure without warning. Even a small leak can empty the system fast under hard braking. Get the car towed - do not drive it, even just to a shop.
Fresh brake fluid is clear to amber, similar to cooking oil in color. Old brake fluid is dark brown to black. It's slick to the touch and damages paint - never leave it on car finishes.
Internal master cylinder leaks don't drip externally - the seals leak fluid past themselves inside the unit. The pedal slowly sinks as you hold pressure. The fix is master cylinder replacement, $250-500.
Caliper: $150-400 per side. Brake line: $150-500. Master cylinder: $250-500. Wheel cylinder: $100-300. Always do a complete brake fluid flush after any repair - $80-150.
Tell our AI what you see under your car. You'll know what it is, whether it's safe to drive, and what the fix costs - in under a minute.
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