Edicius wrote:
check wheel sensors, they generally throw a code though. Thats about it those, check connectors and stuff too
Exactly right. Most people plug in the code reader and immediately think it will tell them exactly what is wrong. A code will only be set when a fault is detected that is outside of preset variables, this could be caused by a faulty sensor or control unit, but it is usually a bad connection, poor ground, or broken wire. A code reader is a great tool to find the area or circuit where the problem exists, then use common sense and some basic diagnostics to eliminate or locate easy and inexpensive problems before you spend big bucks on modules and sensors
GM did have some problems with the ABS units on their full size pick-up's, I am not sure if this is also a problem with their other lines. If, when doing a brake job you just compress the front caliper pistons the brake pedal will become very low and the ABS will stop working. GM is aware of the problem but does not offer any repairs. Bleeding and/or flushing the system will not remedy the problem. The only way to safely replace front brakes on a GM is to open the caliper bleeders and collapse the pistons by bleeding the excess fluid out of the system. It is believed that contaminates in the fluid cause sticking and leaks within the servo and ABS valve bodies.
