1. The actual braking function is performed by the __________.

A. brake drum

B. foundation brake

C. spring brake

D. brake shoes

E. slack adjuste

2. The foundation brake consists of the __________.

A. brake drum, spider, brake shoes & linings

B. camshafts, return springs, anchor pins & rollers

C. brake chamber, slack adjuster, air lines & fittings

D. A & B

E. None of the above

3. The __________ converts air pressure into mechanical pressure.

A. return springs

B. slack adjuster

C. brake shoes

D. brake chamber

E. None of the above

4. There are __________ types of air-operated foundation brakes used on medium and heavy-duty trucks.

A. two

B. three

C. four

D. five

E. six

5. The three types of air-operated foundation brakes are __________.

A. vacuum, hydraulic & cam

B. hydraulic, wedge & cam

C. cam, wedge & disc

D. cam, wedge & vacuum

E. All the above

6. The slack adjuster converts air pressure into mechanical pressure.

7. Like cam brakes, disc brakes utilize a slack adjuster to transfer force.

8. Wedge brakes utilize a bushing and roller assembly to spread the brake shoes and force the lining against the drum.

9. Disc brakes consist of a rotor, wheel hub, and caliper.

10. The caliper is an assembly that positions the brake pads relative to the rotor.

11. The __________ functions independently of the spring brake chamber.

A. master brake

B. service brake

C. slave brake

D. wedge brake

E. A & C

12. Spring brakes function as __________.

A. service brakes

B. emergency brakes

C. parking brakes

D. All the above

E. None of the above

13. The __________ performs the normal slowing and stopping function.

A. treadle valve

B. service brake

C. spring brake

D. relay valve

E. None of the above

14. The parking/emergency brake contains a __________.

A. diaphragm, piston & lock ring

B. diaphragm, piston & o-rings

C. diaphragm or piston, & large powerful spring

D. diaphragm, piston & drive nut

E. None of the above

15. . __________ are the two main types of spring brakes commonly used on trucks, buses, trailers and other types of heavy-duty commercial vehicles throughout the world.

A. Double-diaphragm & piston-diaphragm

B. Air over hydraulic and double-diaphragm

C. Piston-diaphragm & roto-lock

D. Double-diaphragm & single roll diaphragm

E. None of the above

16. The service push-rod is connected to the foundation brake via a yoke and slack adjuster.

17. A spring brake has two chambers: service brake chamber and parking brake chamber.

18. The parking/emergency brake chamber contains a large, powerful spring.

19. Double diaphragm brakes are the only types of spring brake used on trucks, buses, trailers and other heavy-duty commercial vehicles today.

20. To park the vehicle, air is applied to the parking brake through a valve mounted on the vehicle’s dash.

21. Before proceeding with the recommended inspection procedure, be sure to __________.

A. totally deplete the air system and manually release the brakes

B. turn off the engine and “chock” (or block) the wheels

C. manually release the brakes and engage the transmission

D. turn off the engine and manually release the brakes

E. None of the above

22. A CVSA inspector will __________ if any non-manufactured holes or cracks have been detected in the spring brake housing section of the parking brake.

A. ask you to adjust the brakes

B. place the vehicle “Out-of-Service”

C. provide a replacement brake

D. allow the vehicle to continue operation

E. None of the above

23. On an MGM Brakes spring brake equipped with an external breather-tube, the end of the breather-tube should be inserted a minimum of __________ into each elbow.

A. 1/8-inch

B. 1/4-inch

C. 1/2-inch

D. 3/4-inch

E. None of the above

24. When properly torqued, the clamp band ears should be __________.

A. angled away from each other

B. angled in toward each other

C. parallel to each other

D. touching each other

E. All the above

25. Placing the split or hardened-steel flat washers between the brake chamber and the bracket will __________.

A. allow the chamber to “flex”, resulting in premature failure of the N/P chamber

B. allow the installer to apply an additional 25 Lbs.-Ft. of torque to the nuts

C. provide additional support to the N/P chamber

D. reduce the possibility of corrosion between the bracket and N/P chamber

E. B & C

26. MGM Brakes recommends routine inspection of the brake chambers whenever the equipment is in the shop, or at a minimum of every 75,000 miles.

27. To reduce the possibility of serious injury when removing an “uncaged” actuator, use a vise grip to relieve the pressure being applied to the slack adjuster.

28. If the vent holes in the head of the brake become restricted with dirt or concrete, they can be reamed out using a power drill with a 3/16-inch drill bit.

29. When installing an MGM Brakes spring brake equipped with an external breather-tube, the tube must be positioned in the upper quadrant, 9:00 to 3:00 o’clock, away from the road surface.

30. Any hose with damage extending through the outer reinforcement ply or with a bulge or swelling when air pressure is applied will cause the vehicle to be placed “Out-of-Service” by an inspecting officer.

31. The release bolt should be inserted into the spring brake until it bottoms out, __________.

A. then install the nut and washer

B. then rotate the bolt 1/4 turn counter-clockwise

C. then rotate the bolt 1/2 turn clockwise

D. then rotate the bolt 1/4 turn clockwise

E. None of the above

32. To verify that an MGM Brakes TR2430T Model spring brake has been completely caged to zero (0) stroke, the release bolt thread should extend __________ above the nut.

A. 2.75-inches

B. 3.00-inches

C. 3.25-inches

D. 3.50-inches

E. 4.00-inches

33. To manually release (cage) the power spring on an MGM Brakes Model MG-T piston-type spring brake, the release bolt should __________.

A. extend 4.00-inches above the head of the brake

B. be inserted into the brake and tightened to 40-45 Lbs.-Ft. of torque

C. be completely removed using a 3/4-inch deep well socket wrench

D. turned clockwise until it extends 3.25-inches above the pal nut

E. None of the above

34. Unlike double diaphragm spring brakes, the unscrewing or removal of the release bolt from an MGM Brakes (MG) piston type spring brake __________.

A. does not actually “cage” the power spring

B. only removes the power spring force from the slack adjuster

C. requires a metric socket wrench

D. All the above

E. A & B

35. To make the manual release procedure easier, you can __________.

A. apply lithium grease to the release bolt threads

B. use an air impact wrench

C. apply 90-100 psi air pressure to the air inlet port marked “Spring Brake”

D. remove the air lines to reduce the pressure inside the chamber

E. None of the above

36. Exceeding 50 Lbs.-Ft. of torque on the release-bolt nut at anytime may damage the release bolt or other internal components.

37. The “removable release bolt” is essential to the release procedure and should be stored in the pocket of the brake, or in the glove box or toolbox of the vehicle.

38. To accelerate the release procedure, use an impact wrench to turn the release bolt nut clockwise until the release bolt thread extends above the nut. 

39. MGM Brakes spring brakes equipped with an integral release bolt can be fully caged by turning the release bolt clockwise until the power spring is fully caged.

40. The release bolt of the MGM Brakes Model LTR-L3 will extend 4.00 inches from the head of the brake when the unit is fully caged.

41. To prevent sudden separation of the single/piggyback from the service chamber when the clamp band is removed, __________.

A. extend the service push-rod slightly and clamp it in place with vise grip pliers

B. remove the pin connecting the yoke to the slack adjuster

C. remove the air lines to assure total release of air from within the chamber

D. ensure spring brake is mechanically caged

E. A & D

42. To help “seat” the clamp band, firmly tap around circumference with a plastic or rubber mallet while __________.

A. applying pressure to the clamp band ears with vise-grip pliers

B. using your free hand to gently rock the piggyback from side to side

C. alternately tightening the nuts to 30-35 Lbs.-Ft. of torque

D. turning the release bolt nut in a counter-clockwise direction

E. None of the above

43. To detect air leaks around the clamp band and air fittings, __________.

A. hold the brake under water to see if bubbles appear

B. apply soapy water or leak detection solution

C. apply soapy water or a light mineral oil

D. listen for air escaping from the clamp band and fitting areas

E. None of the above

44. When reinstalling the external breather-tube, be sure to insert the end of the tube __________ into the rubber elbow extending from the non-pressure housing.

A. 1/4-inch

B. 1/2-inch

C. 3/4-inch

D 1-inch

E. as far as possible

45. Before installing a new diaphragm you should __________ for damage or wear.

A. visually inspect the return spring

B. visually inspect the piston plate

C. visually inspect the non-pressure chamber

D. visually inspect the flange case

E. All the above

46. When installing new clamp band bolts and nuts, it is best to completely tighten one of the nuts before tightening the other.

47. When reinstalling the air supply lines, apply a non-hardening sealing compound to the fittings and tighten them to 25-30 Lbs.-Ft. of torque into the chamber air inlet ports.

48. If leaks are detected around the circumference of the clamp band, tighten the clamp band bolts until the leaks cease.

49. When storing the release bolt in the storage pocket on the brake, tighten the release bolt nut against the flat washer to 10 lbs.- ft. of torque.

50. To uncage a spring brake with an integral release-bolt, use an impact wrench and turn the bolt until it is fully engaged into the unit and the slotted nut bottoms out.

51. Before you begin to remove the combination/tandem brake from the vehicle, __________.

A. manually release the brake

B. determine the manufacturer of the brake

C. visually inspect the brake for any damage

D. chock or block wheels

E. All the above

52. The “X” dimension is measured from __________.

A. the bottom of the actuator to the end of the piston rod

B. the bottom ot the actuator to the center of the yoke pin

C. the bottom of the actuator to the end of the yoke

D. the end of the rod to the end of the threads

E. None of the above

53. Before marking the push-rod to be cut on the new unit, __________.

A. remove the release bolt and place it in the storage pocket

B. remove the “jam nut” from the push-rod

C. make sure the push-rod is fully retracted to the zero (0) stroke position

D. insert the dust cap into the release bolt hole and snap tightly into place

E. All the above

54. Failure to fully cage (release) the spring brake to zero (0) stroke prior to taking the “X” and “Y” dimensions will result in __________.

A. improper alignment of the slack adjuster

B. the push-rod on the new unit being cut too short

C. the push-rod on the new unit being cut too long

D. improper installation of the yoke and jam nut

E. None of the above

55. When servicing a vehicle equipped with MGM Brakes 3-inch “Long Stroke” spring brakes, it is essential __________.

A. 3-inch “Long Stroke” and 2.5-inch “standard stroke” chambers not be mixed

B. 3-inch “Long Stroke” diaphragms be used to service 3-inch “Long Stroke” units

C. only the piggyback be replaced if the production unit is equipped with the MGM Brakes “Welded Yoke”

D. All the above

E. None of the above

56. The release bolt should be used to manually release the spring brake to assure it can be safely handled.

57. If the yoke pin is rusted or frozen in the yoke, it will be necessary to remove and replace the slack adjuster.

58. Before cutting the universal service push-rod, the “X” and “Y” dimensions should be estimated and marked.

59. Prior to marking the push-rod to be cut on the new unit, the spring chamber and push-rod on the old unit should be fully retracted to the zero stroke position.

60. If the unit being replaced is an MGM 3-inch “Long Stroke” brake equipped with the MGM Brakes “welded yoke”, replacement of the single/piggyback is recommended.

61. Prior to installing the new combination/tandem brake, you should take a few minutes to __________.

A. apply a protective coating of grease to the bracket surface

B. apply a coat of epoxy paint to the bracket surface

C. remove any burrs or debris

D. ensure the bracket surface is free of cracks

E. C & D

62. After the brake has been installed on the bracket, make sure the push-rod is working freely and is square to the chamber bottom within __________.

A. ±5°

B. ±4°

C. ±3°

D. ±2°

E. None of the above

63. A push-rod that is not square to the chamber bottom can be adjusted by __________.

A installing an “off-set” slack adjuster

B. repositioning the chamber on the mounting bracket

C. applying heat to the rod and bending it to fit

D. shimming the slack adjuster to the right or left as required

E. B & D

64. When installing the air lines on the chamber, __________.

A. apply a non-hardening compound to the hose fittings

B. tighten the fittings into the air-inlet ports to 25-30 Lbs.-Ft. of torque

C. be sure each air line is mated to the correct inlet port

D. use soapy water or leak detection solution to check for air leaks

E. All the above

65. When replacing the release bolt into the storage pocket on the brake chamber, be sure to tighten the release bolt nut against the flat washer to __________.

A. 10 Lbs.-Ft. of torque

B. 15 Lbs.-Ft. of torque

C. 20 Lbs.-Ft. of torque

D. 25 Lbs.-Ft. of torque

E. None of the above

66. When mounting the brake to the bracket, be sure to install spacers between the bracket and non-pressure housing.

67. It is recommended that an impact-type wrench be used to tighten the mounting bolt nuts when installing a new chamber on the vehicle.

68. When installing a brake equipped with an external breather-tube, it is important that the tube be positioned facing the road surface.

69. It is important to inspect the push-rod to be sure it is working free and is square to the chamber bottom to within ±6°, in any direction, at any point in the chamber stroke.

70. Failure to install the end cap securely in place on a brake equipped with an external breather-tube will void the warranty.

71. To properly dispose of an old spring brake, MGM Brakes recommends __________.

A. throwing it into a metal scrap bin

B. caging the brake and throwing it into a metal scrap bin

C. that the clamp band bolts be cut with an acetylene gas torch

D. that the coils of the power spring be cut with an acetylene gas torch

E. None of the above

72. When cutting the coils of the power spring with an acetylene gas torch, the brake should be __________.

A. caged and placed in a bucket

B. caged and placed in a vise on a workbench

C. placed on the shop floor, away from combustible materials

D. placed into a properly constructed steel container

E. None of the above

73. The person operating the acetylene gas torch should never do so without __________.

A. proper training

B. proper clothing

C. proper eye protection

D. All the above

E. None of the above

74. To make sure the coils of the power spring have been completely cut, you should __________.

A. remove the chamber from the container and shake it

B. use your finger to see if the coils of the power spring are loose

C. remove the release bolt to see if the brake still works

D. use a screwdriver to check that the coils are loose

E. All the above

75. The proper disposal of old spring brake chambers is a major concern throughout the industry.

76. Spring brake actuators should be safely disarmed to prevent serious personal injury from the sudden accidental release of the high-energy power spring.

77. Wearing protective clothing and eye protection are an option when operating an acetylene gas torch.

78. Cutting through the first coil of the power spring may produce a low pitched “popping” sound and cause the brake to jump inside the container.

79. During roadside inspections, the single most cited reason for a commercial vehicle to be placed “Out-of-Service” is __________.

A. oil soaked brakes

B. bent or crimped air lines

C. audible air leaks

D. out-or-adjustment brakes

E. mismatch of chamber size

80. A fully loaded truck/trailer, traveling at 40 MPH under the best of road conditions, will require approximately __________ feet of stopping distance.

A. 342

B. 298

C. 260

D. 189

E. None of the above

81. A Commercial Vehicle Safety Alliance (CVSA) inspector will place a truck/
trailer “Out-of-Service” if the number of defective brakes is equal to or
greater than __________ of the brakes on the vehicle.

A. 10%

B. 20%

C. 30%

D. 40%

E. None of the above

82. A defective (out-of-adjustment) brake, 1/4-inch or more beyond the
readjustment limit, will __________.

A. count as 1/2 brake toward the 20% rule

B. count as 1 full brake toward the 20% rule

C. need to be replaced with a new unit

D. not have any effect on the “Out-of-Service” status of
the vehicle

E. None of the above

83. The recommended readjustment stroke for a type 30 3-inch (76 mm) “Long
Stroke” brake is __________.

A. 1.75 inches

B. 2.00 inches

C. 2.25 inches

D. 2.50 inches

E. 3.00 inches

84. Proper brake adjustment is critical to the safe operation of commercial
vehicles.

85. A vehicle with 20% of its brakes defective (out-of-adjustment) will be placed “Out-of-Service”.

86. The number of brakes required under the 20% rule for a five (5) axle truck/ trailer to be placed “Out-of-Service” is two (2).

87. The last half of the chamber stroke is more efficient than the first half.

88. The maximum stroke with the brakes adjusted should be as short as possible without lining to drum contact.

89. Because of the performance benefits of 3-inch “Long Stroke” chambers,
CVSA has increased the readjustment limit on Type 30 chambers from
2.00 inches to __________.

A. 2.25 inches

B. 2.50 inches

C. 2.75 inches

D. 3.00 inches

E. None of the above

90. All “Long Stroke” chambers are identified by __________.

A. permanent markings

B. square inlet ports

C. red triangular tags

D. trapezoidal I.D. tags

E. A, B & D

91. Increase in chamber stroke caused by improper brake adjustment has little
or no effect on the distance required to stop the vehicle.

92. Elevated brake temperatures are a major factor in the loss of braking
effectiveness.

93. The performance of 2.50-inch “standard stroke” brakes that are technically in adjustment suffer little or no loss in braking performance when drum temperatures are raised to a realistic operating temperature of 600°F.