Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that there is a leak in one part of the car's brake system, which can make it harder to stop the car safely.
The C055D code indicates that the vehicle's onboard diagnostics system has detected a leak in the hydraulic brake circuit labeled as 'B'. This could affect braking performance.
The C055D code is triggered when the brake control module detects a pressure drop in the hydraulic circuit B of the braking system. This pressure drop is usually due to a leak, which can be caused by damaged brake lines, faulty seals, or worn-out components.
• Reduced braking performance
• Brake warning light on dashboard
• Spongy or soft brake pedal
• Damaged brake lines
• Faulty brake caliper seals
• Worn-out brake master cylinder
Hydraulic: Using liquid to transmit force.
Brake Caliper: A component that squeezes the brake pads against the rotor to slow down the vehicle.
• Inspect brake lines for visible leaks or damage.
• Check brake fluid level in the reservoir.
• Perform a pressure test on the brake system.
• Replace damaged brake lines.
• Replace faulty seals or calipers.
• Refill and bleed the brake system to remove air.
• Brake line wrench
• Brake fluid
• Pressure tester
$150 - $500
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly check brake fluid levels.
• Inspect brake lines for wear and tear.
• Replace brake components as recommended by the manufacturer.
Hydraulic System Issue
• Do not drive the vehicle until the issue is resolved.
• Seek professional repair service to ensure safety.
Brake system components may be covered under the vehicle's powertrain or specific brake warranty. Check with the manufacturer.
This code has been associated with vehicles that have experienced brake system failures due to lack of maintenance or harsh driving conditions.
High – Brake system issues can lead to serious safety risks if not addressed promptly.
Driving with a malfunctioning brake system is unsafe and may be illegal. Ensure repairs are conducted by a certified professional.
• Vehicle must be stationary.
• Brake system must be pressurized.
The hydraulic brake circuit B is typically located within the brake lines and components on the vehicle's chassis.
Q: Can I drive with a C055D code?
A: No, driving with a brake system leak is unsafe and should be repaired immediately.
Q: How do I know if my brakes are leaking?
A: Signs of a brake leak include a soft brake pedal, reduced braking power, and visible fluid leaks under the vehicle.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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