atasa 5 drum brake systems · 2019-02-18 · 1. since they can handle 2040% of passenger car...

ATASA 5 TH Study Guide Chapter 49 Pages: 14571480 Drum Brakes 42 Points

ATASA 5 th Drum Brake Systems Please Read The Summary

Before We Begin…

Keeping in mind the Career Cluster of Transportation , Distribution & Logistics

Ask yourself:

What careers might be present in this slide series?

What careers might interest me?

How do these careers relate to my other high school classes?

What career cluster is my 4year plan preparing me for?

1. Since they can handle 2040% of passenger car braking and can be built with a simple __________ brake mechanism, drum brakes continue to be often used for rear wheel brakes.

Drum Disc Parking

ATASA 5 th Drum Brake Systems

2. Drum brakes selfmultiply their force (called ________ _____________) due to a wedging action caused when the shoe tends to follow the rotating drum and is stopped by the anchor pin or plate.

SelfEnergizing ServoAction SuperOptimization


3. Brake shoes and their associated “hardware” are mounted to a steel ______________ plate.

Mounting Backing Packing


4. The brake shoe ____ & rim are the steel parts to which the lining is attached.

Well Web Support


5. The ________ on the brake shoe rim ride against the backing plate & should be lightly lubricated.

Nubs Nibs Nobs


6. The __________ or leading shoe is the one towards the ______ of the vehicle

Primary, Front Secondary, Rear Parking, Center


7. The ___________ or trailing shoe is the one towards the ____ of the vehicle.

Primary, Front Secondary, Rear Parking, Center


8. An ____________ pin limits rotation of the shoes on the backing plate. Anchor pin @top = servo brakes

Anchor Holddown Retaining


9. Brake linings are fastened to the shoe webs by either _________ or ____________ means.

Riveting, Bonding Screwing, Gluing Welding, Soldering


10. Colorcoded ____ (retracting) springs attach the shoes to the anchor pins.

SelfAdjuster Hardware Kit

Return Springs

Holddown Springs Return HoldDown SelfAdjuster


11. ____________ springs or other anchor hardware hold the brake shoes against the backing plate.

Return HoldDown SelfAdjuster


12. The inability of drum brakes to ____________________ heat causes brake fade and is the main reason that disc brakes have replaced drum brakes at the front of cars & trucks.

Dissipate Hesitate Obliterate


13. ________________ drum brakes have doubleended wheel cylinders and an anchor pin at the top of the backing plate which allows the shoes to bite deeper (self energize) into the drum as it rotates and then push (servoact) the secondary shoe against the anchor pin.

Duoservo Uniservo Nonservo


14. In normal forward braking, the friction developed by the _______________ lining is greater than the primary lining due to servoaction, so the secondary shoe is thicker w/more surface area.

Secondary Primary Center


15. Self ______________ (automatic) designs can be either cable or leveroperated variations.

Adjusting Assembling Engaging


16. __________ drum brakes are often known as leadingtrailing shoe systems. They have no servoaction. The anchor is located at the bottom of the backing plate & wheel cylinder at the top.

Duoservo Uniservo Nonservo


17. Quality brake work begins w/a road test to verify customer complaint, a thorough _____________ using a checklist, diagnosis, and finally a complete job with replacement of all faulty components.


18. __________________ is often the first indication of wear problems & the #1 customer brake complaint.

Heat Noise Grabbing


19. In every case, a road test must be done _______________ brake work to ensure proper operation! “Check your work when complete”

Before During After


20. Tire, steering, suspension & wheel bearing problems can all cause vehicles to pull. True or False


21. It may be necessary to unadjust the brake shoes and also backoff the ________________ brake adjustment in order to remove the brake drums since they may have an internal ridge from wear.

Drum Disc Parking


22. Selfadjusters can be accessed through an adjusting ________ in the backing plate so they can be loosened in order to make drum removal easier. Use a thin screwdriver or a special tool for this.

Slot Gouge Dimple


This unadjusts the shoetodrum fit


23. Push nuts or __________ ________ are used during manufacture for temporarily holding drums on to hubs. It is ok to discard them once they are removed in the shop.

Speed Nuts Peanuts Mixed Nuts


24. Leaking wheel cylinders and rear _________ seals must be repaired before replacing brake shoes.

Axle Disc Drum


25. Damaged drums can be machined by turning or grinding on a brake _____________. Maximum outofround of brake drums should never exceed .006” (pedal pulsation could occur)

Mill Lathe Surface Grinder


26. Drum maximum inside diameter should never exceed___________ over original size. ( .060” = 1.5 mm ) Some drum discard diameters are .090” or .2.mm over the standard inside diameter

.060”

.020”

.005”


27. Drum I.D. must be kept within .010” of each other for equal sidetoside braking. True or False


28. Machining the inside diameter of drums changes the liningtodrum fit (arc). True or False


29. Arc, radius, offset, contour, eccentric or _________ ground brake shoes provide a better fit into drums that have been machined oversize to restore proper friction surfaces.


Yam Cam Ram

Oversized drum fitted to std. shoes results in reduced contact area

and brake heat fade


30. Freshly machined as well as brand new drums must be cleaned with special ____________ solvent or with warm, soapy water and then wiped clean with a lintfree cloth. (This applies to rotors too!)

Brake Asbestos Windex®


Nondrive wheel bearings are often repacked while brakes are being serviced.


31. Backing plate support pads & selfadjuster threads should be lightly __________ during assembly.

Lubed Oiled Ground


32. Final brake adjustment goes quicker if a brake shoe ______ gauge matches shoe to drum diameter.

Adjust Micrometer Set


33. Peel back wheel cylinder ______ ________ to reveal leaks & also check for sticking pistons.

Dust Boots Inner Seals Pistons


34. Dripping wheel cylinders can be either replaced or honed and ______________ with new parts.

Rebuilt Recycled Recorded


35. _______________ brakes can be either hand or foot operated, and are usually mechanical systems. Parking brakes can be vacuum released or mechanically released.

Drum Disc Parking


36. Parking brake cables pull on the internal _________ & _________ mechanism of each rear brake.

Lever & Strut Disc & Drum Pulley & Wedge


Parking Brake Strut

Parking Brake Lever

37. Parking brake systems use levers to multiply driver physical effort: 1) the pedal or hand assembly, 2) the ___________________ lever, 3) the parking brake lever & strut inside the drum.

Equalizer Maximizer Minimizer

1

3

2


38. Parking brake adjustment is the last adjustment after all other brake work is done. True or False


39. Parking brakes should hold the vehicle from rolling in either direction on a ______ º (degree) incline.

90º 60º 30º


atasa 5 drum brake systems · 2019-02-18 · 1. since they can handle 2040% of passenger car...

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