12-42. An overheated wheel brake assembly should be allowed to cool in the ambient air for what prescribed amount of time? 1. 45 to 60 min 2. 35 to 45 min 3. 30 to 40 min 4. 15 to 25 min 12-43. The independent brake system reservoir leakage test is performed by connecting a source of air to the filler port at what prescribed pressure? 1. 25 psi 2. 30 psi 3. 35 psi 4. 50 psi 12-44. To perform an operational test on a power brake valve, you must have a test stand capable of supplying what minimum amount of hydraulic pressure? 1500 psi 2000 psi 3000 psi 4500 psi 12-45. When you are performing an operational test on a power/manual brake valve, the hydraulic fluid must be within what prescribed temperature range? 1. 40° to 90°F 2. 55° to 100°F 3. 70° to 110°F 4. 85° to 130°F 12-46. Before disassembling a master brake cylinder, what device should you install on the end of the piston rod to prevent personal injury? A nut A clamp A rig pin A spring compressor 12-47. During the reassembly of a master brake cylinder, what type of lubricant should you apply to the suspension rod end bearing? 12-48. Excessive heating of a shuttle valve is an indication of what problem? 1. External leakage 2. Internal leakage 3. Defective emergency accumulator 4. Excessive cycling of the emergency pump 12-49. When performing a thermal crack test on an automatic brake adjuster valve, you should crack the valve at what prescribed pressure range? 1. 12 to 17 psi 2. 20 to 29 psi 3. 30 to 37 psi 4. 41 to 45 psi 12-50. After disassembling a brake selector valve you should clean the parts in which of the following substances? Freon Hydraulic fluid Aliphatic naphtha Dry-cleaning solvent 12-51. During a bench test, what is the maximum allowable torque required to rotate the swivel? 1. 30 in.-lb 2. 40 in.-lb 3. 50 in.-lb 4. 60 in.-lb IN ANSWERING QUESTION 12-52, REFER TO FIGURE 12-47 IN THE TEXTBOOK. 12-52. When the brakes are released, what component prevents the piston from returning to its original position? 1. The spring guide 2. The adjusting pin 3. The return spring 4. The retaining ring 12-53. The tapered grip method is used to restrict the movement of the captured torquing-type automatic adjuster? 1. Oil 2 . Wax 3. Grease 4. Hydraulic fluid True False 64