The Kelsey-Hayes EBC310 ABS system, found in 1995 to early 2000s GM trucks like the 2005 GMC Sierra, requires a special procedure for bleeding brakes. This system has three sections: left-front, right-front, and rear axle, each with an isolation valve and a dump-valve/low-pressure accumulator. The accumulator is positioned behind the dump-valve, making it impossible to bleed conventionally.
To properly bleed these brakes, the ABS system must be cycled. The factory-approved method involves using a Tech 1 or equivalent 2005 Gmc Sierra Scan Tool to command the ABS computer. This scan tool allows for precise control over the ABS cycling process, ensuring a complete fluid flush and air removal.
An alternative method, sometimes used by DIY mechanics, involves driving on a gravel or snow-covered road and forcefully applying the brakes to lock the wheels, triggering the ABS. However, this approach has significant drawbacks. First, the brakes must be functional enough for safe driving to the chosen location. Secondly, cycling the ABS in this manner can push air from the accumulators back into the lines, potentially compromising braking performance. Even if successful in activating all three circuits (left-front, right-front, and one rear wheel), further bleeding is necessary after returning.
For a safe and effective brake bleed on a 2005 GMC Sierra, using a compatible scan tool is highly recommended. It ensures proper ABS cycling and minimizes the risk of introducing air into the brake lines. While the “shade-tree” method might seem tempting, it poses safety risks and may not effectively bleed the system.
Properly functioning brakes are crucial for safety, and a professional-grade 2005 GMC Sierra scan tool provides the best way to service the complex ABS system in these trucks. This specialized tool allows for a controlled and thorough bleeding process, resulting in optimal braking performance. Investing in the right tools for the job ensures safety and prevents potential brake system damage.
For a more in-depth understanding of bleeding ABS systems, refer to the July 2005 article “Bleeding ABS Systems” by Bill Williams in Brake & Front End Magazine.
Brake & Front End Magazine, “Bleeding ABS Systems” by Bill Williams (July 2005)
