Bleeding Brakes

Short answer: Bench-bleed the master cylinder first; if the pedal still sinks to the floor afterward, suspect the master cylinder itself — even a brand-new one.

Bench-bleeding the master cylinder:

  1. Secure the master cylinder dead level (this is very important).
  2. Attach a tube to each brake-line outlet and route the other end back into its own reservoir well.
  3. Fill each well with fresh brake fluid.
  4. Push the plunger (pedal pushrod) in with an appropriate tool.
  5. Repeat until no more bubbles appear.
  6. Plug the outlets and put the lid on.

If the pedal still goes to the floor: test the master cylinder by plugging the brake-line outlets and pressing the pedal; if it sinks, fluid is bypassing the internal seals. (One member’s new master was the culprit — the old one bled fine.)

Also: the secondary metering valve (the barrel-shaped valve with a single in/out, under a rubber boot) has a button/pin that must be held down during bleeding (use a C-clamp, wedge, or door stop). That pin is often worn/corroded and can suck air; the valve is no longer available — on a rebuild you may need to replace it with the later “combination valve” (disc front/drum rear) from Classic Performance or Year One (~$60), fabricating a bracket.

Any proposed updates, changes, pictures, and/or corrections, please use our comment section below (may need to click on permalink to access comments feature). Information is subject to change and offered as is without any warranties or guarantees. Please review our Term's Of Use for more information.

Content last modified: June 13, 2026 at 10:06 am

Categories: Wheels, Brakes, and Axle - All, Wheels, Brakes, and Axle - Brakes

← Frequently Asked Questions

Leave a Reply

Your email address will not be published. Required fields are marked *