Models: 2007 – 2008 GM C/K truck
Problem: Some vehicles may exhibit a low or spongy pedal after wheel end brake service that cannot be remedied by bleeding the brakes. This may be due to a prematurely deteriorated seal in the master cylinder. Remove snap ring and rearmost piston from master cylinder to inspect seals. If any deformation or deterioration of seals is present, replace the master cylinder.
For more information, please visit: http://www.brakeandfrontend.com/Article/117091/tech_tip_low_or_spongy_pedal_after_routine_brake_service.aspx