From the proportioning valve the fluid continues its journey to the wheel well

where it is joined to a reinforced rubber flex hose that will allow for movement in the suspension and steering system.  This is required to ensure that the metal line will not have to flex and become weakened by the movement of the vehicle.

At this point we have covered the brake system from where the fluid is stored in the reservoir to where it comes out at a caliper.

The next section that we should discuss is with regard to a wheel cylinder and brake shoes.  To gain a better understanding of this keep in mind that the same master cylinder, lines and hoses run to this as to the calipers.

 The brake shoes as shown here are what bring a brake drum system to a stop.  The charcoal colored material is the friction material that causes friction and heat in order to stop the vehicle.  The black metal portion that it is attached to is used for the purpose of mounting the shoes to the backing plate in order for them to function. 

The shoes are held in place with a number of

clips and springs shown here in a set.  This would be the typical parts packaged into a brake shoe hold-down kit available through any parts supplier.

When the brake shoes are in place and held down properly they would look like the diagram here.

The brake drum encloses the brake shoes and wheel cylinders as shown in this diagram.  The wheel cylinder functions in the same manner as the caliper does only a caliper squeezes inward on the rotor and a wheel cylinder pushes the shoes outward in order to push against both sides of the drum creating the same friction and heat to bring the vehicle to a stop. 

A typical brake drum might look like the one that you see here.  The fins on the outside of this drum have the same purpose as the fins that we spoke of earlier on a rotor.  Enclosed in this drum are the same components that you see in the diagram at the bottom left of this page.

The wheel cylinder is filled with fluid thus putting

pressure on the pistons at each end causing them to protrude and press against the brake shoes as show in the diagram at the top of this page.

Your brake fluid should be replaced approximately once every 24,000 miles / 40,000 km or 24 months in order to keep it functioning at its best.  The current standard for brake fluid set by the Department of Transportation is DOT 3 and has a boiling point of approximately 460 deg. F.  Brake fluid is subjected to an immense amount of heat in order to bring your vehicle to a stop and thus must keep all of its chemical properties so that it will not fail and cause brake "fade" or perhaps fail to stop your vehicle at all.  Brake fluid is very susceptible to absorbing moister which will drastically lower the boiling point.  Never leave your master cylinder reservoir or a container of brake fluid sitting open to air as it will pull moister from it and change its properties.

We have learned here today that the brake shoes and pads wear out out due to the heat and friction that is caused when bringing your vehicle to a stop.  It is also common for the rotors and or drums to have to be replaced every so often.  They can be machined to bring them back to a smooth surface for the pad or shoe to apply itself to only a couple of times before they are worn out completely and fall below the minimum thickness that is stamped on them for safety purposes.  When a drum or rotor has become too thin it will not dissipate the heat properly to create safe braking. 

We have also learned the brake fluid needs to be changed on a regular basis just like your engine oil does in order for it to retain all of the chemical properties that allow it to function at its peak.

With all of the in mind make sure that you have your brakes inspected often.  You should have an inspection performed approximately every 6,000 miles / 10,000 km or every six months to ensure that they are operating properly.  If you notice any change in the operation of your brakes or a noise that you hear only when applying or only when not applying the brakes take your vehicle in to be inspected.