The trailer hand valve (also referred to as the "trolley valve" or "Johnson bar") works the trailer brakes and should be used only when testing them. The hand valve should be used: A To test the trailer brakes. In air brake vehicles the parking brakes should be used how? CDL Doubles & Triples Practice Test 3 - Classic Mode (1) Temporarily disconnect the tow vehicle/trailer electrical connector and back up the trailer, (without the energizing the backing solenoid valve), to verify brakes are working. Jul 15, 2011 #8. Do not use it in driving because . No other fittings, connections or lubricants shall be used to connect a regulator to a gas cylinder valve. or When the brake pedal does not work. Open the emergency line shut-off valve at the rear of the last trailer. Pulling the tractor ahead gently with the trailer brakes locked. Section 6: Combination Vehicles - California DMV Trailer Air Lines Every combination vehicle has two air lines. 2,821 1,132. When and How to Adjust a Load-sensing Hydraulic Pump or The foot brake is more effective. or Only to test the trailer brakes. Section 4: Tractor Parking, Trailer Charging/ Parking and Emergency Systems Tractor/Trailer Parking and Emergency Systems 31 Park Control Valves 31 Dash Control Valves 32 Tractor Protection Valves 33 Trailer Spring Brake Valves 34-35 Section 5: Convertor Dolly Brakes Trailer/Converter Dolly Brakes 36-37 Section 6: Antilock Braking System Using it while driving could create a skid. You should not back a tractor under a trailer until the whole system is: a) Empty b) At normal pressure c) Between 60 and 80 psi 32) You are coupling a tractor to a semitrailer. 24. ; Never install an agitator or ball valve on the by-pass hose. This feature is particularly important for pneumatic valves where the valve position may not be easy to recognize. The foot brake sends air to all of the brakes on the vehicle including the trailers. It is used to supply the trailer with air, shut the air off and put on the trailer emergency brakes. Which of these statements is true? Go to the rear of the rig. The PROTEGO® sampling and air bleed valve is used for flame transmission-proof venting of pipelines and equipment that transports or processes flammable liquids and for taking liquid samples. The tractor to lose all air pressure B. Validation of Cleaning Processes (7/93) | FDA PDF FEDERAL REGULATIONS - Haldex Best practices on testing pressure relief valves | Bulk ... Let the driver skip the daily tank draining C. Increase tank pressure the way superchargers boost engines D. Reduce the risk of ice in the air brake valves in cold . 2. or This is considered a safe maneuver. Again with just the use of your hands, you should be able to detach the old check valve from your water pump. Release the brakes to recover wheel traction. It may sound complicated, but the whole apparatus can be installed with just an adjustable wrench. A To park at loading docks. 7. D Only with the foot brake. These lines are the service line and the emergency line. For one, all it does it actuate the trailer . i) if the trailer service brakes wrap the seat belt around the trailer hand valve. Use the trailer handbrake to provide air to the service line. Few reasons. The trailer hand valve (also called the trolley valve or Johnson bar) works the trailer brakes. Describe what the trailer air supply control does. SERVICE AIR LINES.— The service line carries air that is controlled by the foot brake or the trailer hand brake. More driving knowledge, questions and answers, online practice tests for obtaining a . or Only when driving on mountain slopes. Tazz Road Train Member. These couplers have a snap-lock position and a rubber seal that prevents air from escaping. The trailer hand valve should be used only to test the trailer brakes. The foot brake sends air to all of the brakes on the vehicle (including the trailer (s)). The foot brake sends air to all of the brakes on the 4) At the brake chamber, measure from the fixed point to the mark on the push rod. 1.2.2 Movement of the Shipping Container All precautions should be taken to avoid the movement of the container during the loading or off-loading operation. or In sub-freezing temperatures. or Only on slippery surfaces. Cracking Pressure - The minimum amount of air pressure (in psi) required to open an air valve. Driving test question about: The trailer hand valve should be used: and possible answers include: Only at highway speeds. The complete converter kit includes brass valve, siphon hose, Teflon tape and pump adapters. When you do this, you should hear: They run between each vehicle, such as tractor to trailer, trailer to dolly, and dolly to second trailer. Only when parking C. Only to test the trailer brakes D. Both B & C above. The trailer hand valve should be used only to test the trailer brakes. How can you test that air flows to all trailers? As little as possible b. B Only when the trailer is fully loaded. Glad hands. Go to the rear of the rig. What is a bobtail? ∙ 2011-08-12 03:28:01. D. Brake hard with the pedal and hand valve until you stop 13. Wargames, Jul 14, 2011. The air brake leakage rate for a combination vehicle (engine off, brakes off) should be less than __ psi per minute. and possible answers include: Always. True or False? Describe what the trailer air supply control does. 3/2-Way valves are suitable for several tasks: driving pneumatic actuators, blow-off, pressure release and vacuum applications. Bypass valve is opened to re-circulate solution back into the tank. To avoid strai ning the angle valve, the non -sparking wrench used to remove and replace fittings should not exceed 18 inches in length. of the danger of making the trailer skid. The tractor brakes to keep working properly C. The trailer supply valve to stay open D. The tractor brakes to lock up 12. Anytime the vehicle is parked c. To hold your speed when going downhill d. Only during pre-trip and post-trip inspections 25. 50% . Resume braking. The "open-close" position of the major valves should also be identified. Do not use the trolly bar (trailer hand brake). You should hear air escaping, showing the entire system is charged.  a. pressure protects the tractor air supply in the event of loss of pressure in a trailer   b. routes trailer supply air and service . anti-cavitation trim: See "trim, anti-cavitation". This questions appears in the following tests: Illinois Tank 1 , Illinois Tank 1 , Spring brake relay valve (where applicable) 6. watching the dash gauges for a pressure drop.Dual brake valve 7. 1. the foot brake sends air to all the brakes on the vehicle ( including the trailer(s)) 2. More driving knowledge, questions and answers, online practice tests for . There is much less danger of causing a skid or jackknife when using just the foot brake. The trailer hand valve (also called the trolley valve or Johnson bar) works the trailer brakes. There is much less danger of causing a skid or jackknife when using just the foot brake. The . Return to the cab of the truck and set the trailer brakes by either pulling out the red trailer air supply valve or pulling down the trailer brake hand valve. Why should you never use the trailer hand valve while driving? Using the hand valve before applying the brake pedal should not be done. This will supply air to the emergency (supply) lines. The original poster is right, Not a good idea at all using the trailer hand valve, and for anyone new in trucking, I would not recomend them even looking at the valve. Best Answer. What is the purpose of the emergency air supply line? 6. 3. The hand valve is added so that the driver can apply the trailer's brakes independent of the tractor.. You must have an Endorsement A specified on your licence to operate a vehicle equipped with an air brake system. or The trailer may skid. Before backing under the trailer you should: a. More driving knowledge, questions and answers, online practice tests for obtaining a drivers license, passing driving exams and . It is important not to let water and oil build up in the air tanks. When connecting the glad hands, start . Where fitted, the trailer shunt valve . Before connection is made, couplers should be clean and free of dirt and grit. Do not use it in driving because of the danger of making the trailer skid. With two 2/2-way valves the function of a 3/2-way valve can be mimicked. Using the hand valve before applying the brake pedal results in less skidding than only the brakes. You should expect the trailer brakes to apply and: A. It is not used in driving because of the danger of making the trailer skid. A To park at loading docks. Using it while driving could create a skid. 7. This will supply air to the emergency (supply) lines. 10. Never use the trailer hand valve while parking because doing so may release the air pressure from the braking system, releasing the brakes that are holding the vehicle in place. The connection should be fine. Should the gas/air mixtures or product vapor/air mixtures ignite during venting, the valve prevents flash back into the protected system . The firm should challenge the analytical method in combination with the sampling method(s) used to show that contaminants can be recovered from the equipment surface and at what level, i.e. More driving knowledge, questions and answers, online practice tests for obtaining a drivers license, passing driving . Open the emergency line shut-off valve at the rear of the last trailer. A relay valve is an air-operated valve typically used in air brake systems to remotely control the brakes at the rear of a heavy truck or semi-trailer in a tractor-trailer combination. d. The pump should be deadheaded by closing the manual hand valve. The hand valve should be used: a. To test the trailer brakes b. 10. Using it while driving could create a skid. The trailer hand valve should be used only to test the trailer brakes 3. all the above If your vehicle has an alcohol evaporator, it's there to: A. 3) If the trailer brakes have applied you come up to the front of the trailer and pull the glad hand off the trailer. Only at highway speeds B. You are driving a 100 foot twin trailer combination at 50 mph. The foot brake sends air to all the brakes on the vehicle (including the trailer(s'). c. Rock the trailer back and forth with the trailer brakes locked X Your answer was . The trailer hand valve should be used only to test the trailer brakes. When should you use the hand valve to park a combination vehicle? You are coupling a tractor and semi-trailer and have connected the air lines. Automatic limiting valves may be used on vehicles manufactured after this date. Driving test question about: You should not use the trailer hand valve while driving because: and possible answers include: You should use the parking brake. from TruckersCombination Vehicle (CDL) Endorsement. Whenever you brake strongly, check your mirrors. Control is a post FMVSS 121 term and service is a pre FMVSS 121 term. 2. You supply air to the trailer tanks by: A Pushing in the trailer air supply valve. Describe what the trailer air supply control does? Using a brake controller while towing a trailer involves setting up the controller, adjusting to the load size, adjusting braking sensitivity, manually activating the trailer brakes and possibly choosing a few personal settings. 18. The trailer hand valve works the trailer brakes. By-pass hose must be open and unrestricted at all times. Boom valve is opened to broadcast spray with the boom. Release the truck's brakes by pushing in the yellow parking brake valve. See Answer. Back valve. Trailer brakes will not immediately apply When valve is pulled. B Pulling out the trailer air supply valve. or Never. True or False? If the service line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away? A 9 B 10 C 11 D 12 3. Which of these statements is true? The connection should be fine. Wargames, Jul 14, 2011. Regulators are designed to be fitted directly to the cylinder valve. Step 3: Install the new check valve. Low pressure indicator(s) 4. When driving a set of doubles, it is necessary to close which shut-off valve in the last trailer? or To park on a grade. Typical applications. 5) Type 30 Brake Chamber equipped with manual slack adjusters has a maximum allowable push rod travel of 1 3/4 inches (44 mm). Manual limiting valves can be used on front steer axles on vehicles manufactured before March 1, 1975 and only be used to limit the front brakes in adverse road conditions. Which of the following best describes the primary function of a tractor protection valve (TP)? 11. It is not used in driving because of the danger of making the trailer skid. from TruckersDouble & Triple Trailer (CDL) Endorsement. Press hard on the brake pedal and apply full hand valve until you stop b. Close the emergency line valve. The trailer hand valve should be used only to test the trailer brakes. The trailer hand valve works the trailer brakes but should only be used when testing them. angle valve: A valve design in which one port is collinear with the valve stem or actuator, and the other port is at a right angle to the valve stem. Describe what the service line is for: Use the trailer hand brake to provide air to the service line. Once installed, it works like the hand pump kit. ; Never run any pump without a pressure control valve or regulator installed. If freezing conditions exist, flush pump and hoses with a 50/50 mixture of anti-freeze and water. Wargames, Jul 14, 2011 #7 + Quote Reply. Only the valves on the back of the first trailer should be closed. The trailer hand valve is used only to test the trailer brakes. c. Supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes. System pressure shifts the compensator valve to de-stroke the pump exactly the amount necessary to limit system pressure to the compensator setting, 3,000 psi as shown in Figure 3. (2) Pull trailer forward and stop suddenly, pin on side of actuator should not travel more than about ½ way in slot for single brake axle or ¾ way in slot Both may reduce braking force by as much as 50% and automatics must not limit above 85 psi. IMPORTANT: Keep suction valve open whenever system is being operated. 11),, Trailer Charge Dash Valve (red octagon knob) Will not automatically pop out When air pressure is below 40 PSI. from TruckersCombination Vehicle (CDL) Endorsement. a. trailer hand valve c. foot valve   b. trailer supply valve d. treadle valve  ____ 44. Now that you were able to remove the old check valve, you can replace it with a new . a. You should keep at least ____ seconds of space ahead of you. The correct answer is a.