Bench Bleeding Brake Master CylinderBench bleeding your new master cylinder will enable you to install it faster, and with a firmer pedal. The only additional items needed will be either one or two (according to if you have a single or double line system) short looped brake lines with clear plastic tubing fit to the ends. These can be made from old brake lines or you can order a new line (get one that has double male ends and cut it in half).
Before beginning be sure the system is ready for the installation of the master cylinder (wheel cylinders, calipers, brake hoses all installed). This will minimize the leeching of fluid after the master cylinder is bled. Place the master cylinder in a bench vise being sure it is level (this will facilitate the removal of all the trapped air). Attach the looped brake lines to the master cylinder. Position them so the fluid will travel in an upward motion and have the clear plastic lines end in the fluid reservoir (the tubes will need to be secured so they won’t come out of the reservoir). This way the master cylinder will re-feed itself. Fill the reservoir to the recommended level and using a wooden dowel, a blunt metal rod, or a large Phillips screwdriver, compress the master cylinder plunger with slow, complete strokes. You will see the fluid enter the tubes with many air bubbles. As you continue the bubbles will be fewer and fewer. When all bubbles disappear be sure the reservoir is at the correct level, then using a piece of plastic (sandwich bag plastic) between the cap and bowl, screw down the cap securely. The plastic will help prevent the bleed down of the fluid. Now you can remove the looped brake lines and install the master cylinder.
The system can now be bled as recommended from the wheel cylinders and calipers (be sure to remove the piece of plastic before attempting this). Any questions or suggestions can be directed to
ron@5RRestorations.com or call 281-346-2417.
