HEAVY/ HEAVY DUTY BRAKES exam questions and answers

in the AL factor the L refers to the? length of the slack adjuster Spring brakes on an air-brake vehicle must be able to hold the vehicle, facing uphill or downhill, on what percentage grade? B 20% How much free movement should exist between a slack adjuster and its camshaft? .005 in. max The warning light on a truck with a antilock brake system light when the truck is started. When the truck is moving, the light stays on. which of the following could be the cause? Misadjusted wheel sensor THEORY OF OPERATION BRAKES ARE DESIGN TO COVERT THE ENERGY OF MOTION INTO HEAT ENERGY DISSIPATE THAT HEAT INTO THE AIR COEFFICIENT OF FRICTION the ratio between the force necessary to move one surface horizontally over another and the pressure between the two surfaces. THE RETARDER HORSEPOWER GENERATED BY THE BRAKES, THEN MUST BE SEVERAL TIMES THAT OF THE ENGINE, OFTEN THE AMOUNTS TO OVER 100 RETARDING HORSEPOWER AT EACH WHEEL END. HYDRAULIC BRAKE THE ONLY MECHANICAL LEVERAGE THAT IS USED IS IN THE FOOT PEDAL LINKAGE HEAT DISSIPATION BRAKE DRUM/ROTOR ACTS AS A HEAT SINK AND A HEAT EXCHANGER SERVICING THE HYDRAULIC BRAKE SYSTEM IS A MATTER OF ADJUSTMENTS, REPLACEMENT OF WORN OR DAMAGED PARTS AND CORRECTION OF DAMAGE CAUSE BY GRIT, DIRT OR CONTAMINATED BRAKE FLUID FLUID LOSS FLUID MAY BE LEAKING PAST THE PISTON CUPS IN THE MASTER CYLINDER OR BRAKE CYLINDERS FLUID CONTAMINATION PLACE SMALL AMOUNT OF THE DRAINED BRAKE FLUID INTO A SMALL CLEAR GLASS BOTTLE. SEPARATION OF THE FLUID INTO DISTINT LAYER WILL INDICATE MINERAL OIL CONTENT PRESSURE DIFFERENTIAL SWITCH IS USED TO WARN THE VEHICLE OPERATOR THAT ONE OF THE