Brake Bleeding + Flushing

Question 1

How often should you flush your brake fluid?

Answer 1

• Brake fluid should be flushed every 2 - 3 years.

Question 2

What is the process of brake bleeding?

Answer 2

• It is the process of purging air from the brakes hydraulic system.

Question 3

How do you flush brakes with two people?

Answer 3

One person is opening and closing the bleeder screw, and the other is pushing and releasing the brake pedal.

• bleeder screw is opened
• brake pedal is pushed in.
• Bleeder screw is closed.
• brake pedal is released.
• continue this process till the fluid is clean, and when air is out of the lines.
• after all the brakes have been cleaned - check if the brake is spongy. A spongy brake means there is air in the line.

Question 4

How much power does the front brakes apply?

Answer 4

• The front brakes apply 60 - 80% of braking power.
• This is why the front brakes are needed to be replaced more often than the rear.

Question 5

What is the difference between fixed vs floating brake calipers?

Answer 5

• Fixed has pistons on both sides.
• Whereas, floating has a piston on one side.

Question 6

What is the difference between dual servo + non servo?

Drum brakes

Answer 6

Dual servo:
- primary and secondary shoes
- stronger braking power
- works well in both directions,
- self energizing mechanism (it uses the primary to engage the secondary).
- dual servo has two return springs.

Non servo:
-leading and trailing shoes
- lower braking power
- dependent on drum rotation (shoes wedge to the drum because of drum rotation)
- non servo has an anchor point on the bottom and brake shoe adjustor at the top.

Question 7

What is so special about dual servo brakes?

Answer 7

Dual servo uses a self energizing mechanism where one shoe (primary) pushes against the drum which causes the secondary shoe to engage. The secondary shoe provides 70% of the braking force.

Question 8

REMINDER: Review the parts on Non-servo and Dual servo

Question 9

What is the function of Anti-lock Braking System (ABS)?

Answer 9

• it prevents wheel lock up to reduce stopping distance and help maintain steering control.

Question 10

What is the function of the hydraulic modulator, and what is its other name?

Answer 10

Also known as ABS hydraulic unit; it modulates brake pressure to individual wheels, preventing locking up, and skidding; maintains control on the road.