[12Ounce]

What symptoms caused the master cyl to be replaced?

Master cylinders can be tricky to replace properly.
1. With all the variations (ABS, Trac control, etc) in brake system design .. some year to year ... an exact replacement cylinder is necessary.
2. Sometimes a replacement re-built cylinder is no good ... straight out of the box.
3. Cylinders need to be bench primed.
4. Master cylinders need to be allowed to "fully retract". Poorly returning wheel brake hardware (usually caused by poor cleaning/lubrication) can prevent it. A mal-adjusted plunger link from brake pedal can prevent it... there is an adjustable screw that actually goes inside the master cylinder from brake pedal ... these can be too loose ... or too tight.