the converter dolly air tank drain valve should be
The crack the whip effect will topple the rear trailer first. 0000003977 00000 n Help your friends discover what it takes to become a successful truck driver. The tanks will hold enough air to allow the brakes to be used several times even if the compressor stops working. Learn more and apply here: The more heavily loaded semitrailer should be in first position behind the tractor. Go to Section 4: Other Topics This question is in Section 4: Other Topics of our CDL Test Guide. The shut off valves prevent air from going any further. What is most likely to happen if the trailer protection valve of a double or triple trailer does not function correctly? 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. The braking systems of double and triple trailers are different than those of straight trucks because doubles and triples. Pull gently against the pin of the second trailer. You are doing a walk around inspection of a double or triple trailer rig. With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. 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. C. the service brakes slowly move to the fully applied position, Some large trucks have converted or "spot" mirrors. Never unlock the pintle hook with the dolly still under the rear trailer. This has the same value as the %%TIME_ALLOWED%% Variable on the Final Screen. This will prevent water and dirt from getting into the coupler and the air lines. The road is dry and the visibility is good. Do converter dollies have spring brakes? What will happen if there is a major leak in the service air line? 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. A converter dolly is still under the second trailer when you unlock the pintle hook. Time used (Requires timer add on). For all brakes to work on a triple combination, you must have air supply? None of the above, 2. These mirrors: Make things seem smaller and further away than they really are. Trailer Air Tanks And Shutoff Valves - Page 50. That split second that you release the brakes will allow them to match the vehicles road Secure converter gear support in raised position. When checking the fifth wheel, you should make sure that it has enough? Mar 2 - Mar 3. By clicking on "Sign Up", you agree to our Terms of Use and Privacy Policy. You are driving a triple trailer and there is a loss of air pressure in the emergency line. 0000009556 00000 n CDL Doubles and Triples Test Question and Answers 2023 [PDF]: Commercial Drivers License Doubles and Triples Endorsements Knowledge Test. The emergency line valve open and release air You will not be tested on uncoupling twins unless you want to get a double/triple trailer endorsement on your license. Good speed management says you should: You must drive through deep or flowing water. 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. the rig will continue moving in a straight line no matter how much the steering wheel is turned. If there is a trailer Be sure pintle-eye of dolly is in place in pintle hook of trailer(s). For emergency braking you should: May have poor traction due to bouncing and wheels lockup. B. closed Stop the vehicle by gearing down and sparingly A. How can you test that air flows to all trailers? Should the shut off valves on the rear of the first trailer be open or closed on a set of double trailers? How do you check to make sure trailer height is correct before coupling? should remain in the closed position. You can test that air is flowing to all trailers by opening? Lock pintle hook. B 0000010705 00000 n In the coupling system, the locking jaws should be fixed around? Check them all. Provides a snug fit to eliminate unwanted seepage of air or water. 0000003261 00000 n The dolly tow bar may fly away, possibly causing panic, and making it very difficult You should keep at least ____ seconds of space ahead of you. Locking jaws closed on 2. Ship to Store. 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 Each trailer and converter dolly has one or more air tanks. The individual voltage gains of the first two stages are to be equal, while the gain of the third is to be one-fourth of each of the first two. Which of the following will probably happen if you are driving a double rig and a set of trailer wheels goes into a skid? You should hear air escaping, showing the entire system is charged. When connecting the glad hands, press the two seals together with the couplers at a 90-degree angle to each other. 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. you are driving a 100ft truck eith double trailers at 50mph. . Converter dollies: 11 If you leave this page, your progress will be lost. 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. Use the dummy couplers when the air lines are not connected to a trailer. Air escape from the open valve B The service brakes slowly move to the fully applied position C The emergency line valve open and release air D None of the above 4. True False True If you want to couple a second trailer to you combiantion vehicle, secure it by using the: Trailer emergency air brakes. You should be sure the converter dolly air tank drain valves are ____ and the pintle hook is ____. When uncoupling a rear trailer, your rig should be parked in a straight line on? Why should you not use the trailer hand valve while driving? The emergency brakes come on whenever air pressure in the emergency line is lost. 8. re-couple, You can if you want to, it does not matter. 9 C you are driving on a slippery road during the day. The couplers have a rubber seal that prevents air from escaping. Remember however, that is just a suggestion. C. posted speed limits on curves are safe for all trucks, Empty trucks: B. you need about four times as much stopping distance at 40 mph as at 20 mph 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. Delivering to. The road is dry and visibility is good. If your tanks have automatic drains, they will keep most moisture out, but you should still open the drains to make sure. When you do this, you should hear: Which of these statements about emergency steering is true? What is likely to happen? Also, this page requires javascript. Watch the wording of the question AND the answers A safe driver will look for all of the above. 7. The last trailer in a combination is most likely to turn over. recouple. What does the Commercial Driver Handbook say about how much space you should keep ahead of your truck? If you are only pulling one trailer, make certain the valve is fully in the closed position or it will leak air out of the air system. They provide the air pressure used to operate trailer brakes. The application only takes one minute. Should I Be A Truck Driver? 7.3 Inspecting Doubles and Triples = Additional Things to Check During a Walkaround Inspection. A Open, latched B Open, free C Closed, latched D Closed, free 28. You are visually checking the coupling of a converter dolly to the rear trailer. Locking jaws open Also available in App Store & Google Play. A. allow "much more space" than is needed for ideal driving conditions to do this without wheel chocks you should: supply air to the trailer air system with the tractor and then disconnect the emergency line. Never pull any trailer without visually inspecting the fifth wheel locking bar B. slightly open 0000001775 00000 n If you do, there is a problem. A dolly is like a very short trailer, with a ring hitch on the front and a fifth wheel on top. be coupled to the rear of a tractor-trailer combination forming a hexagon bottom rig, A coupling device of one or two axles and a fifth wheel by which a semitrailer can be If not, there is a problem. The road is dry, and visibility is good. This would be very dangerous. 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: D 2003-2023 Chegg Inc. All rights reserved. A. use a low gear When driving doubles or triples how should they be driven to avoid rollover or jackknifing: A. always keep your vehicle to the right side of your lane B. open; latched The Doubles and Triples written CDL Exam is required for your doubles and triples endorsement. which of these statements about quick steering movements and doubles/triples is true? 0000002636 00000 n Pickup at South Loop. Tips for Backing Up a Trailer Like a Pro Trucker. A These mirrors: make things seem smaller & further away then they really are. 0000001354 00000 n For emergency braking you should: B - Converter dolly air tank drain valve: CLOSED. That there is no space between upper and lower sixth wheel. 1/2 to 3/4 of an inch The dolly tow bar may fly up, possibly causing injury and making it very difficult to re-couple. While doing a walkaround inspection of a double or triple, the converter dolly air tank drain valve should be _____, and the pintle hook should be _____. A connection device of one axle used to disconnect a semitrailer combination vehicle door. 0000008915 00000 n When inspecting doubles and triples you must make sure there is air all the way to the back of the last trailer, otherwise what may not work? Each trailer and converter dolly has one or more air tanks. When does the "driver's manual" advise disconnecting the steering axle brakes to help When inspecting the air brakes on doubles and triples, you wait for air pressure to reach normal, then push in the red trailer air supply knob. The trailer brakes will unlock View the full article to see how to set cruise control correctly! Describe what the trailer air supply control does. on kingpin. 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. "Glad hands" are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer. Ensuring the safety of the public starts with a thorough Do converter dollies have spring brakes? There are more critical parts to check when you have two or three trailers. When testing trailer service brakes, you should use? Typically depends on the axle count. Driving doubles/triples is also more dangerous in hot and cold weather driving, as well as on mountain roads. Eventually, the air will leak away, and then there will be no brakes. 0000001162 00000 n Should the shut-off valves on the rear of the last trailer be open or closed? [California Commercial Driver Handbook] The weight of a truck: Is a major factor affecting stopping distance. To uncouple the rear trailer in a set of doubles, the shut-off valve at the rear of the front trailer should be: Closed. C. if you have traffic on both sides of your vehicle and something is blocking your lane, a move to the right may still be best, To uncouple the rear trailer in a set of doubles, the shut-off valve at the rear of the front trailer should be: A low air buzzer will go off indicating something is wrong and either the front or the 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). Compressed air usually has some water and some compressor oil in it. When the road is slippery New! Nothing, the weight of the trailer will keep it in place, 10. When uncoupling a rear trailer, you should remove some weight from the dolly by? Some large trucks have curved (convex or spot) mirrors. Be sure air-lines are supported and glad hands are properly connected. A 360 degree area of awareness is Allow more following distance. B. keep other traffic out of your side space Open, latched The converter dolly air tank drain valve on coupled double/triple trailers should be: Answer: Closed. Go to the rear of the rig. If you want to couple a second trailer to your combination vehicle, secure it by using: The crack-the-whip effect that troubles trucks with trailers is most likely to cause a tip over: You are driving on a slippery road during the day. 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 coupling twin trailers, you should _______ the pintle hook and secure the dolly support in the _______ position. 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. A sudden movement with the steering wheel can result in a tipping over rear trailer. some large trucks have curved (convex or spot) mirrors. kingpin. Often do not have spring brakes If this lamp is illuminated and does not go out, You need to be aware of how parking lots are arranged in order to avoid a long and difficult escape. The pintle hook should always be secure when the vehicle is in motion. If the fifth wheel on a coupling is too far forward, the tractor frame may hit? Once that's complete, then its an easy push back and the Which diagram shows the best way to turn? For emergency braking you should: Use controlled or stab braking Converter dollies: Often do not have spring brakes The crack the whip effect that troubles trucks with trailers. C Slow to the safe speed before entering, then accelerate slightly through the curve. you want to hook your combination to a second trailer that has no spring brakes. Air valves should be closed on all trailers, Air valves should be open on all trailers, Rear of front trailers: closed, rear of last trailer: open, Rear of front trailers: open, rear of last trailer: closed. We have a new version of this program. How can you be sure you supplied air to a second trailer? You will have greater length and more dead axles to pull with your drive axles than other drivers. C. closed, You can release the dolly brakes by: NPT thumbscrew style design enables easy installation. Connect Converter Dolly to Front Trailer Back first semitrailer into position in front of dolly tongue. 0000005664 00000 n 0000001107 00000 n Open the emergency line shut-off valve at the rear of the last trailer. you should check the trailer height before connecting a converter dolly to a second or third trailer. You are doing a walk around inspection of a double or triple trailer rig. With the red knob pushed in on the tractor dash, the service line should have air in it. B. for doubles and triples, the fifth wheel should be all the way towards the tractor Be certain you are clear at the sides before changing lanes. When you do this, you should hear: If one air system is very low on pressure _______. If it goes low enough, the trailer emergency brakes will come on. B. do not need to be checked as often as flat mirrors because they show a larger area 0000002446 00000 n A. opening the air tank petcock air throughout the system. Hit the article to see the way to back up your trailer like a pro! the fifth wheel, so trailer is raised slightly when dolly is pushed under it. A. you can steer more quickly and safely if you hold the wheel with one hand 0000010783 00000 n C When driving a truck with more than one trailer, which trailer should be first behind the truck? Like a trailer, a dolly equipped with ABS will have a yellow indicator light on the left side. Ideal for replacing a worn, leaky drain valve on a compressor. The dolly tow bar may flip up causing bodily injury and making it very difficult to Any vehicle, regardless of size, designed to transport 16 or more persons, including the driver. To check air flows to all trailers, you should let air pressure reach normal then? You should keep at least ____ seconds of space ahead of you. Any vehicle required by federal regulations to be placarded while transporting hazardous materials. . You may not notice a major leak in the service line until you try to put the brakes on. To help avoid mistakes, colors are sometimes used. 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. We'll help you make the right choices and prepare for a great start to your trucking career. Release Dolly breaks by opening the air tank petcock or if the dolly has a spring break, use the Dolly parking brake control . 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. This has the same value as the %%TIME_USED%% Variable on the Final Screen. What is a converter dolly? C 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. B At TruckingTruth we'll help you decide if trucking is right for you and help you get your career off to a great start. You should be sure the converter dolly air tank drain . Charge the system and pump the brakes with the window down. What is one function of the tractor protection valve? 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. Which of these is the correct answer? 0000003060 00000 n When driving a double or triple trailer, greater care must be given to. In a certain electronic device, a three-stage amplifier is desired, whose overall voltage gain is 42 dB. A B and the converter dolly air tank drain valve should be _____. All ABS equipped units You should be sure the converter dolly air tank drain valves are _____ and the pintle hook is ____. Safety chains should be secured to trailer(s). Sometimes, metal tags are attached to the lines with the words service and emergency stamped on them. A major leak in the emergency line will cause the tractor protection valve to close and the trailer emergency brakes to come on. Seriously! With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. That there is some space between the upper and lower fifth wheel. 5. Push the brake pedal as hard as you can and hold it there