Almost a disaster, a reminder,...and a question

[Drbrown]

Want to add that periodic flushing of brake systems needs to be done using a vacuum device, not by bleeding. My family vehicle uses DOT 5 and the system should be flushed-out every 80,000 miles or 3 years max. Users of DOT 3 and 4 more often. Deterioration of brake fluid is a time-dependant factor rather than mileage. My DOT 5 turns to a yellow-brownish appearance after some time. I have my vehicles flushed periodically and attribute that to my original clutch/brake master cylinders and calipers working fine well into six-figure mileage.

 

[V8 Bob]

Want to add that periodic flushing of brake systems needs to be done using a vacuum device, not by bleeding. My family vehicle uses DOT 5 and the system should be flushed-out every 80,000 miles or 3 years max. Users of DOT 3 and 4 more often. Deterioration of brake fluid is a time-dependant factor rather than mileage. My DOT 5 turns to a yellow-brownish appearance after some time. I have my vehicles flushed periodically and attribute that to my original clutch/brake master cylinders and calipers working fine well into six-figure mileage.

Vacuum, or vac-and-fill, works great on new, dry brake systems at the factory, but using a pressurized bladder-type brake bleeder that pushes fluid from the master cylinder throughout the system and out the bleeders works best on wet systems for both flushing and air removal, imo based on personal experience.
Flushing the brake system every three years is fine, but why not just use DOT 3, 4 or 5.1 The benefits will be much lower cost and a firmer pedal.

 

[Mart]

As the brake shoes wear, the residual valves keep the wheel cylinders extended. With new shoes especially, they wear in and a lot of fluid will "disappear" -- it gets stored in the system. If you adjust the shoes, it goes back into the MC. But I'd surely check the whole system for leaks anyway.

The early ford brakes do not push the fluid back into the system as they wear. By turning the adjusters you just stop the shoes from returning so far.

This is not true for bendix style brakes where adjusting them will push some fluid back.

Mart.