G 2500 3/4 Ton Van V8-305 5.0L VIN M SFI (1997)
Brake Master Cylinder: Service and Repair
Bench Bleeding (with ABS)
The purpose of bench bleeding the brake master cylinder is to remove the air from it prior to installation. This reduces the amount of bleeding needed
after it is installed on the vehicle.
1. Plug the outlet ports and mount the brake master cylinder in a vise with the front end tilted slightly.
2. Fill the brake master cylinder reservoir with clean brake fluid.
3. Using a tool with a smooth rounded end, stroke the primary piston to its fullest stroke, approximately 25 mm (1 inch) several times.
NOTE: As the air is bled from the brake master cylinder, the primary piston will not travel the full 25 mm (1 inch) stroke.
4. Reposition the brake master cylinder in the vise with the front end tilted slightly up.
5. Stroke the primary piston about 25 mm (1 inch) several times.
6. Reposition the brake master cylinder in the vise to the level position.
7. Loosen the plugs one at a time and push the piston into the bore to force the air from the cylinder.
NOTE: To prevent air from being sucked back into the cylinder, tighten the plug(s) before allowing the piston to return to its original position.
8. Keep the brake master cylinders reservoir full of brake fluid.
9. Perform normal bleeding procedures after the brake master cylinder is installed. See: Service and Repair
