While inspecting your converter dolly coupling, you should make sure there is _______ between the upper and lower fifth wheel. Calculate the Mach number at section 2. Air will not be available to release the trailer spring brakes (parking brakes). Blue is used for the service lines, and red for the emergency (supply) lines. Should the shut off valves on the rear of the first trailer be open or closed on a set of double trailers? C. use stab or controlled braking, Which of these is true? not have spring brakes. A The rear trailers shut-off valves should be closed and the front open. some large trucks have curved (convex or spot) mirrors. 9 Questions You Must Ask, Decide if Truck Driving is The Correct Career Path, Do Not Sell or Share My Personal Information. Why should you pull a dolly out from under a trailer before you disconnect it from the trailer in front? A CDL is required to drive any of the following vehicles: A vehicle with two separate parts - the power unit (tractor) and the trailer. if you have traffic on both sides of your vehicle and something is blocking your lane, a move to the right still be best. When you're finished, check your score and results. Any vehicle required by federal regulations to be placarded while transporting hazardous materials. Converter dolly air tank drain valve: CLOSED. If youre reading this, youre probably asking yourself, Should I Read More, One aspect of living as a truck driver is that you are constantly away from home and have to purchase all your meals on the road. Pull gently against them in a low gear to make sure the brakes work. When pulling a single trailer with a Shut-Off Valve, the valves must be in the: Trailers built before what year may not be equipped with trailer spring brakes? If it goes low enough, the trailer emergency brakes will come on. There is more chance for skids and loss of traction. A vehicle transporting hazardous materials is required to display placards where? 0000008187 00000 n For all brakes to work on a triple combination, you must have air supply? B. keep gentle pressure on the brakes while going through the water and for a short distance after coming out Question 4. By clicking on "Sign Up", you agree to our Terms of Use and Privacy Policy. when driving a truck with more than one trailer, which trailer should be first behind the truck? C Which of these is most likely too occur? Study section 6.2 if you can't answer all of these questions. Which the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the trailer. None of the above, 2. C You are driving a 100 ft twin trailer combination at 50 mph. Make sure pintle hook is latched. You should keep at least ____ seconds of space ahead of you. B How can you test that air flows to all trailers? 0000001162 00000 n You should be sure the converter dolly air tank drain valves are ____ and the pintle hook is ____. Connect the Converter Dolly to the Rear Trailer: Test the coupling by pulling against the pin of the second semitrailer. If there are no dummy couplers, the glad hands can sometimes be locked together (depending on the couplings). The application only takes one minute. This has the same value as the %%PERCENTAGE%% Variable on the Final Screen. You should be sure the converter dolly air tank drain valves are _____ and the pintle hook is _____. A driver of a vehicle with double or triple trailers will have greater length and more dead axles to pull, increasing the likelihood of a wreck. For emergency braking you should: A Push the brake pedal as hard as you can and hold it there B Any single vehicle with a GVWR of 26,001 or more pounds, or any such vehicle towing another not in excess of 10,000 pounds. you want to hook your combination to a second trailer that has no spring brakes. C. may have poor traction due to bouncing and wheel lockup, Before you can supply air to the air tanks of a second trailer you need to: In this order, the shutoff valves at the rear of front trailers, the rear of the last trailer and the converter dolly air tank drain valve should be? With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. Locking jaws closed on Allow more following distance. What is a converter dolly? How do you know if your converter dolly is equipped with antilock brakes? View the price and details of this FINSBURY PUMP SYSTEMS 400L (SINGLE STAGE) 5.5HP HONDA GX PETROL ENGINE (18M HOSE) FIRE WATER TANK | Mobile fire units. Each trailer and converter dolly has one or more air tanks. ), a 15 year truck driving veteran, in January 2007. Calculate the voltage gain of each. you are driving on a slippery road during the day. securely fastened. C. fully raised, Which of these statements about speed management and braking is true? D D. Make sure the spare tire is secured, if it has one. Trailer Air Tanks And Shutoff Valves - Page 50. B. for doubles and triples, the fifth wheel should be all the way towards the tractor You are driving a 100-feet truck with double trailers at 50 mph. To check if the converter dolly is securely coupled to the rear trailer you should: Pull gently against the pin of the second trailer. Try our free CDL Doubles and Triples Test Question and Answers Quiz online. If the air supply in the trailer air tank has leaked away, there will be no emergency brakes, and the trailer wheels will turn freely. Safety fail-safe features of a tractor-trailer converter dolly. Be sure air-lines are supported and glad hands are properly connected. The word part ferrit- means: There are two types of converter dollies. You are driving a triple trailer and there is a loss of air pressure in the emergency line. These mirrors: make things seem smaller & further away then they really are. Therefore, it is very important for safety that you use wheel chocks when you park trailers without spring brakes. 5. 12, 3. C. the service brakes slowly move to the fully applied position, Some large trucks have converted or "spot" mirrors. Which of the following will occur? 0000006015 00000 n S-cam brakes are the most common style brakes on large trucks today. You are visually checking the coupling of a converter dolly to the rear trailer. Therefore, look far ahead so you can slow down or change lanes gradually when necessary. Charge the system and pump the brakes with the window down. A They provide the air pressure used to operate trailer brakes. Like a trailer, a dolly equipped with ABS will have a yellow indicator light on the left side. 1/32 to 3/32 of an inch. B You are driving with double trailers and must use your brakes to avoid a crash. Which trailer should come first behind the tractor? If the dolly is a two axle unit then 1 Any combination of vehicles with a gross combined weight rating (GCWR) of 26,001 or more pounds, providing the gross vehicle weight rating (GVWR) of the vehicle being towed is in excess of 10,000 pounds. The dolly will have a yellow lamp on the drivers (left) side. When you're trying to correct a drive-wheel braking skid why should you stop braking? Any trailer, 7. Park the rear trailer against another trailer, chock the tires and lock the trailer Hazardous materials must be placarded on all four sides of EACH Trailer. Hit the article below to see specific information about AOBRDs! True! If this lamp is illuminated and does not go out, Time allowed (Requires timer add on). The trailer height is right when: The trailer will be raised slightly when the converter dolly is backed under it. D If this activity does not load, try refreshing your browser. You can reset the test and retake it as needed. C. posted speed limits on curves are safe for all trucks, Empty trucks: A good and safe driver will always look out for ______. If the spring brakes do not release when you push the trailer air supply control, check the air line connections. If you feel Hb```f``b`c``e@ (Q6_* At section 2 downstream, the speed is 519 m/s. You can test that air is flowing to all trailers by opening? True or False? which of these statements about the handling of doubles and triples is true ? [Flashing Signals, Traffic Signals, Chapter 5 - Signals, Signs and Pavement Markings, North Carolina Driver's Handbook], One component of the DUI sentence in the state of Tennessee is twenty-four hours of litter pick-up wearing clothing that says "I am a drunk driver." What is likely to happen? _______ should be tested with the hand valve but controlled in normal operation with the foot pedal. 1. D C. add "one car length for every 10 mph", Fundamentals of Engineering Economic Analysis, David Besanko, Mark Shanley, Scott Schaefer, Incidental Motions & Motions that Bring a Que. Before you can supply air to the air tanks of a second trailer you need to: Open the shut-off valves at the rear of the first trailer and close the shut-off valves at the rear of second trailer. When the road is slippery good speed management says you should, may have poor traction due to bouncing and wheel lock up. When checking the fifth wheel, you should make sure that it has enough? What value of channel width must the design use? 2. the best way to keep brakes from getting too hot while going down long grades is to : go slow and use only light, steady pressure on the brakes, you are driving a 100ft truck with double trailers at 30mph. Leave the emergency line shut-off valve closed and open the service line valve. B. the emergency line valve open and release air Trucks with trailers have a dangerous crack-the-whip effect. Doubles and triples are extremely prone to control issues and must be and possible answers include: open, free or closed, latched or closed, free or open, latched from TruckersDouble & Triple Trailer (CDL) Endorsement. These mirrors: Make things seem smaller and further away than they really are. Many scientists are concerned that the melting of Earth's sea ice will increase Earth's surface temperature. To check that the trailer emergency brakes are working properly, you should pull out the trailer air supply control and? When coupling twin trailers, you should _______ the pintle hook and secure the dolly support in the _______ position. B. you need about four times as much stopping distance at 40 mph as at 20 mph The number of correct answers. Converter dolly air tank drain valve: CLOSED Air lines supported and glad hands properly connected. ADVERTISEMENT ADVERTISEMENT Once you have coupled your rear trailer, you should test the coupling by? When checking your air lines, they must be secure and? It is extremely unlikely you will drive a trailer built before 1975, but for the written exam, you still may need to know that trailers built before 1975 were not required to have spring brakes. The road is dry, and visibility is good. Closed, free, 8. Opening the shut off valves on the rear most trailer will ensure the lines are flowing C. always keep your vehicle to the left side of your lane, When testing the coupling of double trailers, the landing gear of the rear trailer should be: A. make things look smaller and farther away than they really are If spare tire is on converter gear (dolly), make sure it is secured. Number of wrong answers. Types of converter dollies. When you are pulling trailers, which of the following statements is true about steering? Select the answer that correctly completes each statement. Pickup at South Loop. the converter dolly air tank drain valve on couple double/triple trailers should be: to check if the converter dolly is securely coupled to the rear trailer you should: pull gently against the pin of the second trailer. The shut off valves, when in the open position, allows air to flow out to another trailer. Open, free When doing a walkaround inspection of a double or triple trailer, the shut-off valves should be _______ at the rear(s) of the front trailer(s) and ________ at the rear of the last trailer. Good speed management says you should: You must drive through deep or flowing water. To test the tractor protection valve, charge the trailer air brake system, turn off the engine, and You must check that all shut-off valves are in the open position except the ones at the back of the last trailer, which must be closed. when testing the coupling of a double trailer the landing gears of the rear trailer should be, you must drive through deep or flowing water . the rig will continue moving in a straight line no matter how much the steering wheel is turned. You must check that all shut-off valves are in the open position except the ones at the back of the last trailer, which must be closed. HK Extended Tank Drain Assembly Kit with 10 Inch Braided Steel Hose 1/4 Inch Drain Valve and Elbow Fitting for Air Compressor 4.7 (463) $1499 FREE delivery Thu, Mar 9 on $25 of items shipped by Amazon Small Business All Tool Depot Air Compressor Drain Valve Replacement for Craftsman Petcock 072-0001, 072-0006 (1-Pack) 4.2 (20) $649 A safe speed on a curve for a straight truck or a single trailer combination vehicle may be too fast for a set of doubles or triples. The road is dry and visibility is good. Antilock Braking Systems on Converter Dollies, Converter dollies built on or after March 1, 1998, are required to have antilock brakes. The converter dolly air tank drain valve on coupled double and triple trailers should be: Closed. You should NOT: You are driving a set of doubles and a set of trailer wheels goes into a skid. This has the same value as the %%SCORE%% Variable on the Final Screen. A low air buzzer will go off indicating something is wrong and either the front or the It is important not to let water and oil build up in the air tanks. The driver will be required to complete this requirement in three eight hour shifts. Do converter dollies have spring brakes? You must stop, yield to traffic and pedestrians, and only proceed when safe. 0000003998 00000 n B. closed . D The service air line is only used to control the service brakes (when you press on the brake pedal or use the trailer hand-valve). . In the coupling system, the locking jaws should be fixed around? However, converter dollies and trailers built before 1975 are not required to have spring brakes. The road is dry and visibility is good. 0000008894 00000 n A. use light, steady pressure on the brake pedal Visually check to make sure that the lead trailer is slightly higher than the center of the trailer height is right when: the trailer will be raised slightly when the converter dolly is backed under it. You MUST have air all the way to the back for all the brakes to work. Park on level ground, put chock on the tires, and charge the air tank. The converter dolly air tank drain valve on coupled double/triple trailers should be: Closed. B. slightly raised Those that do not have spring brakes have emergency brakes that work from the air stored in the trailer air tank. safe speed would be 40 MPH. A. use the engine brake or speed retarder kingpin. B When entering a roundabout, a driver must yield the right-of-way to drivers already in the roundabout and obey all traffic signs. Doubles and triples are more likely to turn over than other combination vehicles because of the "crack- the-whip" effect. This will let the rear wheels roll again and keep the rear wheels from sliding. The converter dolly air tank drain valve on coupled double/triple trailers should be: Answer: Closed. A. release the spring brakes and check for movement 7.3 Inspecting Doubles and Triples = Additional Things to Check During a Walkaround Inspection. 1/3 For example: If you are traveling 60 MPH and it begins to rain, your suggested That there is some space between the upper and lower fifth wheel. All rights reserved Site Map. Closed, latched during normal operation the brakes of the double/triple trailer are controlled by : which of these will result in the best control on curves? Their drawbars differentiate them. What three methods can you use to secure a second trailer before coupling? Locking jaws closed on A Commercial Drivers License Overview, Trucking Terminology and Transportation Definitions. The road is dry and the visibility is good. View More Details. The couplers have a rubber seal that prevents air from escaping. Which of these are the correct positions for shut-off valves in doubles and triples? Definition. For emergency braking you should: You shouldn't stop braking. 1/2 to 3/4 of an inch In order to receive your Doubles and Triples endorsement, it is required that you pass the states official CDL written Knowledge exam. the trailer will be raised slightly when the converter dolly is backed under it the best way to keep brakes from getting too hot while going down long grades is to : go slow and use only light, steady pressure on the brakes you are driving a 100ft truck with double trailers at 30mph. D Your tractor protection valve control should pop out, or go from normal to emergency position, when air pressure falls into what range? Only trailers designed to be pulled with another trailer behind it will have a shut off valve. For a particular IC-fabrication process, the transconductance parameter kn=400A/V2,k_{n}^{\prime}=400 \mu \mathrm{A} / \mathrm{V}^{2},kn=400A/V2, and Vt=0.5V.V_{t}=0.5 \mathrm{V}.Vt=0.5V. The rear trailers shut-off valves should be open and the front closed. The last trailer in a combination is most likely to turn over. If you're only pulling one trailer, the shut off valves should always be closed or else the air will simply escape out the back of the trailer. The braking systems of double and triple trailers are different than those of straight trucks because doubles and triples. 0000004668 00000 n 4. This has the same value as the %%TOTAL%% Variable on the Final Screen. which of these statements about managing space to the sides is true? A converter dolly is If a converter dolly has spring brakes, you release the brakes by You have connected the converter dolly to the front semitrailer and then connected the rear semitrailer to the converter dolly. fifth wheel, so trailer is raised slightly when dolly is pushed under it. Otherwise, the dolly tow bar may fly up, possibly causing injury and making it very difficult to re-couple. The dolly tow bar may fly up, possibly causing injury and making it very difficult to re-couple. What types of trailers can get stuck on raised crossings? Each tank has a drain valve on it, and you should drain each tank every day. A. fully lowered You should look into the back of the fifth wheel on a dolly to see if it is locked onto the kingpin, A safe speed on a curve for a straight truck or a single trailer combination vehicle may be too fast for double or triple trailers. Each trailer and converter dolly has one or more air tanks. Watch the wording of the question AND the answers A safe driver will look for all of the above. Open the emergency line shut-off valve at the rear of the last trailer. cQ 220rd8bihuM#Om>G*Lz)g^\l9'A9/omf|b49U[@%jGT-QR6i. The rear trailers shut off valves should be closed and the front open to allow air to the Clean the couplers and rubber seals before a connection is made. With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. B. you can almost always stop more quickly than you can turn When driving doubles or triples how should they be driven to avoid rollover or jackknifing: B. do not need to be checked as often as flat mirrors because they show a larger area You should keep at least ____ seconds of space ahead of you. D Which of these statements about quick steering movements and doubles/triples is true? Unless you are draining the condensation out of the air tank, then the drain valve Hook dolly to front trailer. Safety chains should be secured to trailer(s). Which of these statements about the handling of doubles and triples is true? B. johnson bar If there is air there, then there is air towards the cab You want to hook up to the first trailer, then the converter dolly while it is lined up in The road is dry and visibility is good. These mirrors: Also available in App Store & Google Play. the crack-whip effect that triubkes trucks with trailers is most likely to cause a tip over when. If a converter dolly is still under the second trailer and you unlock the pintle hook, what will probably happen? 11 The lighter semitrailer should be in first position behind the tractor. Older trailers do not have spring brakes. You wish to turn right from one two-lane, two-way street to another. The pintle hook should always be secure when the vehicle is in motion. you should avoid traveling next to others when possible. A green traffic light allows the driver to go. You are driving with double trailers and must use your brakes to avoid a crash. It is important to check the height of the trailer before connecting a converter dolly to a trailer. A converter dolly is still under the second trailer when you unlock the pintle hook. Should I Be A Truck Driver? [California Commercial Driver Handbook] The weight of a truck: Is a major factor affecting stopping distance. When uncoupling, you should never unlock the _______ with the dolly still under the rear trailer. 0000009577 00000 n The Verge logo. How do you check to make sure trailer height is correct before coupling? 8. What should you check for when inspecting the converter dolly and the pintle hook? Shut-off valves (also called "cut-out cocks") are used in the service and supply air lines at the back of trailers used to tow other trailers. Eventually, the air will leak away, and then there will be no brakes. C A Connect the Converter Dolly to the Rear Trailer: Test the coupling by pulling against the pin of the second semitrailer. Mar 2 - Mar 3. TestPermit.com is not affiliated, endorsed, or sponsored by state agencies or any motor vehicle and any other departments in the United States, Canada, UK. 0000003977 00000 n If you do cross the air lines, supply air will be sent to the service line instead of going to charge the trailer air tanks. mTouch Quiz will automatically populate the fields below. B. 9. You should reduce your speed by about _____ on a wet road. C. use a light touch on the accelerator and brake pedals, For coupled double and triple trailers, all of the converter dolly shut-off valves should be: C 0000001375 00000 n This section explains how important it is to be careful when driving with more than one trailer, how to couple and uncouple correctly, and about inspecting doubles and triples carefully. It's a fifth wheel, not a sixth wheel. 0000005554 00000 n first check for battery voltage to the valve by probing the wires of the electrical connector with a volt-meter it should be about 10.5 volts if not it's probably bad.next remove the valve. Single axle converter dollies are the most common type of converter dolly used in the U.S. C-dolly The C-dolly has two separate couplings, side-by-side. 2 "Glad hands" are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer. The number and size of air tanks varies among vehicles. b. cell For emergency braking you should: Any time you have to Any trailer with a reduced ground clearance What is a converter dolly? Tractor-trailers are considered combination vehicles. CDL License Requirements State By State. At section 1, where the cross-sectional area is 0.02 m2m^{2}m2, the air is at 40.0 kPa (abs), 60C60^{\circ} \mathrm{C}60C, and M=2.0. Use controlled or stab braking Simply click in your answer to each CDL practice test question. Learn more and apply here: TruckingTruth was founded by Brett Aquila (that's me! All material on this website is copyrighted. If you're pulling more than one trailer, all valves should be open except the very last trailer, which should have all valves in the closed position. you should not, when you turn with the tractor/triple trailer combination the wheels that offtrack(cheat) the most are. A turn of the glad hand attached to the hose will join and lock the couplers. You have not finished your quiz. B. releasing the pintle hook Open Go to Section 4: Other Topics This question is in Section 4: Other Topics of our CDL Test Guide. second trailer will be connected, The dolly will have a yellow lamp on the left side, The dolly will have a yellow lamp on the right side, The dolly will have a red lamp on the left side, The dolly will have a red lamp on the right side. Submit your email at the end of the test. To do this without wheels chocks you should: Supply air to the trailer air system with the tractor and then disconnect the emergency line. 0000001354 00000 n When you uncouple twin trailers, the last step is to Converter dollies You want to hook your combination to a second trailer that has no spring brakes. What do you check when making a visual check of coupling? Never unlock the pintle hook with the dolly still under the rear trailer. C 10. Locking jaws open All of the above, 6. You should be sure the converter dolly air tank drain valves are ____ and the pintle hook is ____. C. closed, You can release the dolly brakes by: Should the pintle hook be latched or unlatched when backing a dolly under the second trailer? There are more things that can go wrong, and doubles/triples are less stable than other commercial vehicles. The application only takes one minute. Often do not have spring brakes The road is dry and visibility is good. How many different ways of coupling and uncoupling trailer combinations are there? In order to supply air to the air tanks of a second trailer, you must ______ shut-off valves at the rear of the first trailer and ________ the shut-off valves at the rear of the second trailer. the road is dry & visibility is good. Safety should never take second place, so know your stuff! You should keep at least _____ seconds of space ahead of you: You are driving with double trailers and must use your brakes to avoid a crash. They provide the air pressure used to operate trailer brakes. You can find it here: High Road 2.0. You will have greater length and more dead axles to pull with your drive axles than other drivers. front of the second trailer. Some do. you are doing a walkaround inspection of a double or triple trailer rig. You should be sure the converter dolly air tank drain valves are _____ and the pintle hook is ____. C Ship to Store. The crack the whip effect that troubles trucks with trailers. A. completely open In normal operation, trailer service brakes should be operated by? rear brakes will not work properly. Either the front or the rear brakes will not work properly or fully. Compressed air usually has some water and some compressor oil in it. Explain why the waves that reflect from the far left edge of the plates in the given figure earlier exhibit destructive interference (zero intensity) at x=0x=0x=0. We'll help you make the right choices and prepare for a great start to your trucking career. A. closed; latched 0000010705 00000 n This will prevent water and dirt from getting into the coupler and the air lines. Nothing will happen, but an in-cab warning indicator will let you know about the problem, It will cause the tractor protection valve to close and the trailer emergency brakes to come on, It will cause the tractor protection valve to open and the trailer emergency brakes to come on, When you try to put the service brakes on, air will quickly leak and will lower the air tank pressure, possibly activating the trailer emergency brakes, The emergency brakes will come on automatically as soon as a major leak occurs, Nothing, but braking power will be reduced, Air pressure will quickly leak away, even if you are not using the service brakes, Using a combination of the emergency air line and the service air line, Supply air will be sent to the service line instead of going to charge the trailer air tanks which means the trailer spring brakes will not release, Newer vehicles automatically detect if the lines are crossed and will auto-correct itself, Air will continue filling the air holding tanks until the tanks rupture from excessive pressure, Supply air will cause all brakes to release and the truck will roll freely without any braking ability, Trailers typically do not have their own air tanks, Designed to turn off the truck engine when a brake failure occurs, Used in the service and supply air lines at the back of trailers used to tow other trailers, Placed at each trailer spring brake and are designed to engage the emergency brakes when air pressure becomes too high, The yellow and red air control knobs located in the cab of a truck, Used to secure the trailer kingpin to the tractor 5th wheel, Caps which cover the valve stems on tires, A name for the yellow and red air valves in the cab of a truck, Coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer, Email Updates When New Articles Are Posted.