Bob's Studebaker Resource Website

Master Cylinder Bench Bleeding

You've seen this method described

Let's change it a bit. Guaranteed better results...

All master cylinders have that mysterious aura of which brake line goes to which circuit (port). The ANSWER is that the port that has the LONGEST stroke always goes to the front brakes. You can visually select the port that has the long stroke and many MC's are different. When you bench bleed an MC, always do the front brake circuit first. The internal components are designed to push fluid and the largest amount, to the front brakes using different spring rates. Bleeding one side at a time assures a good job. Realistically, you don't have to watch both lines simultaneously while the procedure is ongoing, which could allow an error.

At a rate of about 1" per sec, force the piston in to the cylinder. After the piston is all the way in, hold it in place and pinch the bleed tube tightly to prevent backflow from the bottle, then release the piston. The fluid level in the MC reservoir will drop some on each stroke, but diminishing as the cylinder fills. You should have a bottle of fluid standing by to refill the reservoir as you progress.

See this Page for more on port assignments

  rfj/mar 2016