The drum brake consists of backing plate, brake shoes. Parts plus assumes no liability for an incorrect procedure. Thinly coat all the parts except the dust caps wit brake cylinder fluid. In 1969, chevrolet offered the camaro with manual or power brakes and both were available with either discs or drums.
Where the drum is pinched between two shoes, similar to a conventional disc brake, it is sometimes called a pinch drum brake, although such brakes are relatively rare. Components of drum brake advantages and disadvantages of. The drum brake assembly further includes a member having a first portion operatively connected to the brake shoe and a second portion extending through the third of the three openings provided in the backing plate and secured to the fixed, nonrotatable component of the vehicle, wherein during application of the drum brake assembly the member. Many drum brakes present problems related to extended age and mileage as well as regular wear and an incorrectly serviced drum brake can cause noise, pulling, grabbing and pulsation. Drum brakes advantages include common available parts, low cost parts. If you own an older vehicle, economy car or a trailer, its possible your rear brake drums need maintenance or replacement sooner rather than later. Pdf detailed strength analyses of drum brakes used in light and. Mar 04, 2015 disc brake seminar and ppt with pdf report. Guideline specifications for replacement brake lining assemblies and drum brake linings for powerdriven vehicles and their trailers 1. Once the drum is removed, you should be able to see the inner workings of the drum brake assembly. This page contains disc brake seminar and ppt with pdf report.
Breakin period for electric drum brakes burnishing prior to any adjustments, your coach brakes should be burnishedin. Bendix a2ls hyd drum brakes wparking manual pdf download. A2ls hyd drum brakes wparking automobile parts pdf manual download. Before replacing the brake shoes, check that there is grease on the backing plate under the lever. Nov 30, 2015 some vehicles have disc brakes at all four wheels, but still use a small drum brake housed within the wheel hub assembly as an emergency or parking brake. Drum brakes work on the same principle as disc brakes. If you own an older vehicle, economy car or a trailer. Complete guide to disc brakes and drum brakes les schwab. A brake drum assembly of a light passenger vehicle which is used for the analysis is shown in figure 3. Although fourwheel disc brakes currently dominate the import brake service market, millions of drum brakes are serviced each day in independent import shops. Disc brake seminar ppt with pdf report study mafia. How to replace drum brakes autozone car care youtube. Maintenance manual 4 cam brakes and automatic slack. Recommended service intervals are after the first 500 miles and then every miles.
Disc brakes are a brake system that slowly a wheels rotation by force an attached element disk in a viselike hydraulic caliper. Brake systems, capability, and delivery synergies bendix brand foundation drum brakes are standard equipment on many of the industrys leading truck, axle, and suspension oes. If the clicking sound of the adjuster is not audible from either brake drum. Before proceeding with disassembly, place the oil drain pan underneath the drum brake assembly, and then thoroughly spray the entire assembly with brake cleaner. Drum brakes are an older style of brake, not common on todays vehicles. Diy rear drum brakes, do it yourself rear drum brakes pep boys. Inside each drum brake is a wheel cylinder that expands with the surge of brake fluid, pushing the brake shoes against the inside of the brake drum. While disc brakes are simpler and more resistant to heat fade, the duoservo, selfadjusting drum brake. If your trailer is equipped with hydraulic drum brakes, the brakes are activated by the surge actuatorcoupler located on the front end of the. Complete drum brakes dexters drum brake line services product for the light, medium and heavy duty axles, with ratings up to 27,500 lbs. Electric brakes the electric brakes on your trailer are similar to the drum brakes on your automobile. The drum brake assembly further includes a member having a first portion operatively connected to the brake shoe and a second portion extending through the third of the three openings provided in the. When the brakes are applied, only the caliper pistons move, pressing the brake pads against the disc. The backing plate, which is made from steel and is attached to steering or.
Brakes should be manually adjusted after the first 200 miles of operation, then periodically every 3,000 miles. Drum brakes are well protected from outside elements and are usually less likely to corrode. Many of the cars were ordered with just the basic manual drum brakes, but upgrading is very easy. Twowheelers such as scooters, commuter bikes, threewheelers including autorickshaws widely use drum brake system for braking. The backing plate, which is made from steel and is attached to steering or suspension components by bolts and supports the wheel cylinder, brake shoes, and levers 2. Drum brakes shoes are composed of a metal carrier part 3 and friction lining 4. Adjustment adjust the brakes measure free stroke 32 commercial vehicle safety alliance cvsa guidelines measure push rod travel or adjusted chamber stroke.
For further information on wheel cylinders, refer to drum brake assemblies in this chapter. With all of the brake components connected into the system, the brake should. Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper. Drum brakes are more susceptible to brake fade because most of the heat that builds up within the system is retained longer than with disc brakes. Retracting spring is used in these types of brakes 6. Electric brakes the electric brakes on your trailer are similar to the drum brakes.
Electric drum brakes will require a breakin period to achieve full performance. Guideline specifications for replacement brake lining. Acdelco 18b403 professional rear brake drum assembly. Mechanical drum brakes brake shoe replacement alko. Hydraulic drum brakes and components the primary components of the drum brake system are. Mar 23, 2012 if you need new drum brakes, this video shows you how to replace them with stepbystep instructions. While disc brakes are simpler and more resistant to heat fade, the duoservo, selfadjusting drum brake can generate as much stopping force as a disc brake and will provide many, many miles of maintenancefree driving. A related type of brake uses a flexible belt or band wrapping around the outside of a drum, called a band brake. Inspect the threads of the adjuster assembly for smooth rotation. Before replacing the brake shoes, check that there is grease on the backing plate under the lever assembly at the bottom, use molybdenum grease as required. Drum brakes are common on collector cars and are still widely used on the rear axles of new vehicles. The breakin period is a typical phenomenon with drum brakes and especially electric drum brakes.
Mechanical drum brakes brake shoe replacement take off the wheel, remove the grease cap and split pin, undo the spindle nut then take off the drum. The basic difference is that your automotive brakes are actuated by hydraulic pressure while your electric trailer brakes are actuated by an electromagnet. I replace the drum, springs, and shoes in a ford, but the process applies to most other cars with drum brakes. Brake pedal and booster assembly brake master cylinder assembly at the wheels there are either disc calipers and rotors, drums and brake shoes, or a combination of both. A drum brake assembly comprising a drum rotatable about an axis and having an inner cylindrical surface which forms a braking surface, a support, a brake shoe of generally circular loop form, means. Use a large screwdriver to remove the rear wheel covers.
Brake caliper and disc rotor drum brake assembly hydraulic brake systems guide page 6. Many cars have drum brakes on the rear wheels and disc brakes on the front. Drum brakes retain heat and are more complex than disc brakes but are often the more economical and powerful brake type to use in rear brake applications due to the low heat generation of rear brakes, a drum brakes selfapplying nature, larger friction surface contact area, and long life wear characteristics %life usedkw of braking power. View and download bendix a2ls hyd drum brakes wparking manual online. The shoes are pulled away from the drum by the springs when the brakes are released. When the emergency brake is applied, a lever attached to a cable forces the shoes apart. Block the front wheels and set the parking brake to keep the vehicle from rolling. Working of drum brakes drum brakes work on the same principle as the disc brakes.
This manual has several features which make it easy to use online. Remember, for parts, tools, and advice, get in the zone. Drum brake diagram how drum brakes work howstuffworks. Maintenance manual 4 cam brakes and automatic slack adjusters. Many cars have drum brakes on the rear wheels and disc brakes. The wheel hub and brake assembly components should be. Drum brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs. The importance of drum brake self adjusters know your parts. Its rigidly fastened to a brake caliper bracket or the spindle. Each brake is uniquely designed to meet stopping power needs of the designated capacity, while yet conforming to the requirements of the applicable tire and wheel sizes. They are tested to isots 16949 quality system standards and. The solution should be applied with low pressure to prevent dust from becoming airborne.
For more brake topics and links to related auto articles, check out the links below. The basic difference is that your automotive brakes are actuated by hydraulic pressure while your electric. They are tested to isots 16949 quality system standards and validated for balance to provide better braking performance. Many of the cars were ordered with just the basic manual drum brakes, but upgrading. This maintenance manual describes the correct service and repair procedures for meritor hydraulic and mechanical brakes. Parking brake is a mechanical parking brake system for applying rear wheel brake assemblies.
A drum brake assembly comprising a drum rotatable about an axis and having an inner cylindrical surface which forms a braking surface, a support, a brake shoe of generally circular loop form, means mounting said shoe on said support and permitting said shoe to move relative to said support to adopt either an inoperative configuration at which. Actuatortrailer dealer please provide these instructions to the consumer. Oct 27, 2017 drum the average cost for the drum and brake pads of a drum brake can be around 77% less expensive than comparable disc brake components. This section describes how i overhauled the rear brakes. The drum brake spindle has a backing plate where the wheel cylinder and brake shoes mount. Drum brake assembly photo gallery by r slaughter at. The drum brake diagram below shows how all the parts of the brake work together. Dexter 12 x 2 rim clamp style mobile home brake drum 5 on 9. T h es toc k d rumb ap i nl f than the disc brake spindle, so even a gm disc brake bracket will not work on the drum brake spindle.
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