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. When the brakes are applied, only the caliper pistons move, pressing the brake pads against the disc. 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. 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. 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. Maintenance manual 4 cam brakes and automatic slack. Hydraulic drum brakes and components the primary components of the drum brake system are. A2ls hyd drum brakes wparking automobile parts pdf manual download. Electric brakes the electric brakes on your trailer are similar to the drum brakes on your automobile.
Disc brakes are a brake system that slowly a wheels rotation by force an attached element disk in a viselike hydraulic caliper. This section describes how i overhauled the rear brakes. Drum brakes are an older style of brake, not common on todays vehicles. The breakin period is a typical phenomenon with drum brakes and especially electric drum brakes. With all of the brake components connected into the system, the brake will operate as. Remember, for parts, tools, and advice, get in the zone.
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. Maintenance manual 4 cam brakes and automatic slack adjusters. Retracting spring is used in these types of brakes 6. 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. Disc brake seminar ppt with pdf report study mafia. By installing a booster and a dual master cylinder, you will increase your camaros stopping power. 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. View and download bendix a2ls hyd drum brakes wparking manual online. Mar 04, 2015 disc brake seminar and ppt with pdf report. When the emergency brake is applied, a lever attached to a cable forces the shoes apart.
For further information on wheel cylinders, refer to drum brake assemblies in this chapter. Recommended service intervals are after the first 500 miles and then every miles. 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. If the clicking sound of the adjuster is not audible from either brake drum. 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. Actuatortrailer dealer please provide these instructions to the consumer. Before replacing the brake shoes, check that there is grease on the backing plate under the lever. 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. Complete guide to disc brakes and drum brakes les schwab. Parking brake is a mechanical parking brake system for applying rear wheel brake assemblies. I replace the drum, springs, and shoes in a ford, but the process applies to most other cars with drum brakes. If your trailer is equipped with hydraulic drum brakes, the brakes are activated by the surge actuatorcoupler located on the front end of the.
Electric drum brakes will require a breakin period to achieve full performance. Many of the cars were ordered with just the basic manual drum brakes, but upgrading. 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. How to replace drum brakes autozone car care youtube. 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. The drum brake consists of backing plate, brake shoes. Before proceeding with disassembly, place the oil drain pan underneath the drum brake assembly, and then thoroughly spray the entire assembly with brake cleaner. Thinly coat all the parts except the dust caps wit brake cylinder fluid. 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. Use a large screwdriver to remove the rear wheel covers. Acdelco 18b403 professional rear brake drum assembly. Many of the cars were ordered with just the basic manual drum brakes, but upgrading is very easy. The basic difference is that your automotive brakes are actuated by hydraulic pressure while your electric trailer brakes are actuated by an electromagnet. Block the front wheels and set the parking brake to keep the vehicle from rolling.
Brakes should be manually adjusted after the first 200 miles of operation, then periodically every 3,000 miles. The connection between the metal part and friction lining can be achieved by riveting main parts of rear drum brakes. Many cars have drum brakes on the rear wheels and disc brakes. The importance of drum brake self adjusters know your parts. Drum brakes are common on collector cars and are still widely used on the rear axles of new vehicles. Many cars have drum brakes on the rear wheels and disc brakes on the front. The backing plate, which is made from steel and is attached to steering or.
For more brake topics and links to related auto articles, check out the links below. Once the drum is removed, you should be able to see the inner workings of the drum brake assembly. 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. 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. The basic difference is that your automotive brakes are actuated by hydraulic pressure while your electric. The breakin period is a typical phenomenon with drum brakes and especially electric. 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. Acdelco professional brake drums are constructed with g3000 sae qualified material for structural integrity and maximum service life. Electric brakes the electric brakes on your trailer are similar to the drum brakes. Inspect the threads of the adjuster assembly for smooth rotation. A brake drum assembly of a light passenger vehicle which is used for the analysis is shown in figure 3.
Brake caliper and disc rotor drum brake assembly hydraulic brake systems guide page 6. Complete drum brakes dexters drum brake line services product for the light, medium and heavy duty axles, with ratings up to 27,500 lbs. The wheel hub and brake assembly components should be. A related type of brake uses a flexible belt or band wrapping around the outside of a drum, called a band brake. Its rigidly fastened to a brake caliper bracket or the spindle. 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. 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. Although fourwheel disc brakes currently dominate the import brake service market, millions of drum brakes are serviced each day in independent import shops. Pdf detailed strength analyses of drum brakes used in light and. Drum brake assembly photo gallery by r slaughter at.
Components of drum brake advantages and disadvantages of. 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. Mar 23, 2012 if you need new drum brakes, this video shows you how to replace them with stepbystep instructions. Guideline specifications for replacement brake lining assemblies and drum brake linings for powerdriven vehicles and their trailers 1. They are tested to isots 16949 quality system standards and. It also has some disadvantages such as the drum heats up and expands away from the lining material increasing fading and drum brakes have lower efficiency in.
Bendix a2ls hyd drum brakes wparking manual pdf download. The drum brake spindle has a backing plate where the wheel cylinder and brake shoes mount. Parts plus assumes no liability for an incorrect procedure. Working of drum brakes drum brakes work on the same principle as the disc brakes. Drum brake diagram how drum brakes work howstuffworks. Guideline specifications for replacement brake lining. Twowheelers such as scooters, commuter bikes, threewheelers including autorickshaws widely use drum brake system for braking. The shoes are pulled away from the drum by the springs when the brakes are released. If you own an older vehicle, economy car or a trailer. Drum brakes shoes are composed of a metal carrier part 3 and friction lining 4. Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper. The solution should be applied with low pressure to prevent dust from becoming airborne. This manual has several features which make it easy to use online.
Mechanical drum brakes brake shoe replacement alko. 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. Drum brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs. They are tested to isots 16949 quality system standards and validated for balance to provide better braking performance. With all of the brake components connected into the system, the brake should. In 1969, chevrolet offered the camaro with manual or power brakes and both were available with either discs or drums. 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. 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.
This maintenance manual describes the correct service and repair procedures for meritor hydraulic and mechanical brakes. Drum brakes are well protected from outside elements and are usually less likely to corrode. Diy rear drum brakes, do it yourself rear drum brakes pep boys. 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.
795 1478 634 362 416 1447 694 320 1136 1397 660 592 1459 274 835 1004 722 155 288 1064 17 407 1124 871 665 433 325 883 354 1220 497 1510 613 554 857 1047 113 546 298 142 915 477 470 235