This question is in Section 3: Air Brake of our CDL Test Guide. Your email address will not be published. This ways that the hydraulic pressure required to cease the car won't be accomplished, and your brakes may not work properly. The braking light can mean various things depending upon the vehicles make or model, and actual reviews should start with the liquid level. The last portion of the test requires the driver to build up air pressure again to 120-125 psi, in order to test the service brakes. How many red reflective triangles should you carry? Automotive brake mechanisms are critical and should appropriately test before manufacture. Both the braking booster and emergency brake indicators must illuminate. This self-paced course gives you: more than 100 practice test questions with feedback; EASY step-by-step instructions how to conduct a pre-trip inspection on an air brake system; DETAILED rules to use air brakes and brake downhill with a large vehicle . If you're working with a hydraulic system, information technology'southward important to exam information technology regularly. Second, make certain you're non blocking traffic when you're doing your pre-trip. To the rear. If it does, there may be a leak or other problem. Park your vehicle on a level surface and set the emergency brake, Place a big pan or catch basin underneath the hydraulic restriction line where it connects to the wheel cylinder or caliper, Have an banana slowly depress the brake pedal while yous watch for any dripping fluid from the connexion point, If there is no sign of leaking, have your banana pump the brakes several times earlier holding down firmly on the pedal to check for leaks again, Repeat steps 3 and 4 at each connection betoken until y'all are satisfied that there are no leaks in the organisation. If the parking brake works, release it and test the service-brake . To check for leaks at specific points in the system, you tin use a paw-held vacuum pump and gauge to check for pressure level loss at each connectedness bespeak. How do I know if my hydraulic brake system is bad? Make sure the vehicle is on the level surface and the air pressure is within the normal operating range(cut-out and cut-in). Quote From The CDL Manual: But the brakes, tires, springs and shock absorbers on heavy vehicles are designed to work best when the vehicle is fully loaded. How do you get air out of a hydraulic system? Watch the video! This will help keep your car from rolling as well, but should merely be used as a final resort. The repair price for an entire brake jobrotors, calipers, drums, pads, cylinderscan run you $750 or more. If everything looks expert so far, appoint your parking brake and repeat steps ii-4 with your foot off ofthe pedal entirely (this tests your emergency brake). An easy way to test the operation of the check valve is to disconnect the hose from the brake booster with the engine off (See Image 2). Cracked or broken spring hangers. Yous don't want to get caught taking also long and getting a ticket. Top rated: 3 Lowest rating: 1 Summary of article content: Articles about To test for leaks on hydraulic brake systems: - CDL prep To test for leaks on hydraulic brake systems:: Pump pedal 3 times, then apply firm pressure and hold, Pump pedal 3 times, then get out and look under the Grinding Sound Under Braking. Poor traction, 9. Start the vehicle and turn the wheel to full lock to check the brake hose for issues. Pump the brake pedal three times, then firmly push the pedal for 5 seconds. Stab braking: Release the brakes when the wheels lock up. 3. If you want to drive a truck or bus with air brakes, or pull a trailer with air brakes, you need to read this section. Apply and hold the service brakes for a minute. The enlargement is gradual with cone angles of (a) 6060^{\circ}60, (b) 3030^{\circ}30, and (c)(c)(c) 1010^{\circ}10. Any loose, cracked, broken, or missing frame members. Trailer coupling devices. Check engine vacuum at idle with a vacuum gauge. With the vehicle stopped, pump the pedal three times, apply firm pressure for 5 seconds, then hold and see if the pedal Are only needed if hazardous materials are being hauled Use these questions to test your knowledge of information covered in the Commercial Driver's Manual.Section 2Subsection 2.1What is the most important reason for doing a vehicle inspection?What things should you check during a trip?Name some key steering system parts.Name some suspension system defects.What three kinds of emergency equipment must you have?What is the minimum tread depth for . Hydraulic Brake Check Check that the warning buzzer and/or light is off. If you experience dangerous at any time, movement to a different location. 11.1.1 - Class A Pre-Trip Inspection I f you are applying for a Class A CDL, you will be required to perform a pre-trip inspection in a Class A combination vehicle that you have brought with you for testing. Check the suction side of the system for leaks. Adjacent, check the restriction hoses for any leaks or damage. Hydraulic brakes are a vital component of any vehicle, ensuring that the driver has the necessary control and stopping power to safely operate their vehicle. How do you test hydraulic brakes for leaks? Check that air flows to all trailers: Use the tractor parking brake and/or chock the wheels to hold the vehicle. How to test the air loss rate? Start the vehicle. If the vehicle has air brakes, do the checks described in Sections 5 and 6 of this manual. 917kg/m3, 1025kg/m31025 \mathrm { kg } / \mathrm { m } ^ { 3 } Next, assess brake lines for rust or other harm, and keeping in mind that investigating the brake hose and lines, check for liquid spillage. Then apply firm pressure to the pedal and hold for five seconds. This sign shows an upcoming side road. Once you lot accept confirmed that in that location are no leaks, you can go along to pump the pedal harder and faster until you reach total pressure. Turn the key to the on position, do not start the truck. No loose, worn, bent, damaged or missing parts. Test for hydraulic leaks. Take more free practice tests for other CDL topics with our CDL Test now! How do you test a hydraulic brake booster? To the front What is the weight of the heaviest bear that the ice can support without sinking completely beneath the water? In most cases, you dont lose any brake fluid. Answered, How Tall is a 275 65R18 Tire? Must grab steering mechanism to test for looseness. Air pressure will drop, allow pressure to stabilize. A vehicle is loaded with very little weight on the drive axle. How do you test the foot brake on a hydraulic system? the time of your test, the examiner will direct you to the areas of the vehicle to inspect for the test. A vacuum leak from the brake booster can cause unregulated air in your induction system and create a lean fuel mix in the engine. If your cars braking gets tested, you might notice mechanical concerns before developing. The NY CDL air brakes test consists of 25 questions, and you'll need at least 20 correct answers to pass (80%). Read here. How do you test the foot brake on a hydraulic system? Pump the brake pedal five times fast and quickly let go. To drive a vehicle with air brakes, you must pass the air brake component of the New Mexico CDL knowledge test. 2. What may result? Hydraulic braking is utilized in automobiles to provide rapid stopping. Look directly at oncoming headlights only briefly. When you speed rises to your maximum safe speed , repeat the snub braking technique. This will requite you lot an indication of how much force per unit area is required to fully engage the brakes. Can a leaking brake booster cause rough idle? Ride the car at your own risk if there is a discrepancy in functioning. What is the difference between controlled braking and stab braking? Vibration or Wobbling Feel. What should be done if a hydraulic booster is found to be faulty? To finish the investigation, step through a short examination cruise all over the parking garage to track down the most awful of the issues. The proper way to hold a steering wheel is at clock positions ____ and ____. If the vehicle has air brakes, do the checks described in Sections 5 and 6 of this manual. Your leak test, which you not only have to do as part of your daily pre-trip inspection. They can be asked questions about pressure issues, the foundation of the brakes, how to test the air leak rate, and much more. Texas General Knowledge CDL Practice Test. How do you check for air brake leaks? Hydraulic brakes are components of a vehicle's braking system that use fluid pressure level to transfer force from the pedal to the wheels. You can find these leaks using an ultrasonic gun or by simply placing a small drop of oil or grease around the suspected leak site. If it does, there may be a leak or other problem. D "Valid" means that the file Balanced in the cargo area It should be replaced. To test booster function once the reserve is depleted, hold moderate pressure on the brake pedal and start the engine. if the vehicle has hydraulic brakes, pump the brake pedal three times. [Commercial Driver Handbook] While not a perfect test, it is an indicator of a problem. CDL subsection 2.2 and 2.3 test your knowledge, HR 4 TOPIC 8 TELECOMMUNICATIONS (technology a, Fundamentals of Engineering Economic Analysis, David Besanko, Mark Shanley, Scott Schaefer, Introduction to Thermodynamics and Heat Transfer. Save my name, email, and website in this browser for the next time I comment. Splash the pivot center point with quality entering oil before eliminating the brake drum. Home FAQ Quick Answer: How To Test Hydraulic Brakes For Leaks. You need at least 4/32-inch tread depth in every major groove on front tires. This is called hydroplaning. It may result in a loss of braking and steering control. It can take up to 1 second for the wheels to start rolling after you release the brakes. three. Get it fixed before driving. answer : W T Correct answer is (b) With the vehicle stopped, pump the pedal three times, apply firm pressure for 5 seconds, then hold and see if the pedal moves. So, how do you test hydraulic brakes for leaks? :: Bus & truck drivers are the only public sector that has its own police force (DOT, CVSE, MTO, etc. D Brake chambers. the pedal should not move. How do you test the hydraulic brakes for leaks? Check the service (foot) brake operation by moving the vehicle forward slowly (about 5 mph) and apply the brake firmly. See Figure 2.3. Pump the brake pedal five times fast and quickly let go. two. Replacing the brake booster will fix this problem. Save my name, email, and website in this browser for the next time I comment. The repair price for an entire brake jobrotors, calipers, drums, pads, cylinderscan run you $750 or more. B Make sure the air pressure is above 90psi. What is the Most Mutual Problem in a Brake Hydraulic Organization? Explore now! to install app, Test for Hydraulic Leaks. The second test is a flow check. Check for outside spillage, and if there is none, slacken the expert chamber and check the back ace chamber seal. How Do I Know If Theres a Problem with My Cars Brakes? Must be able to obtain CDL within 6 months after hire . 11.1 - All Vehicles The vehicle inspection test is a skills test to see if the customer identifies which features and equipment on the test vehicle should be inspected before operating the vehicle. . Contaminated restriction fluid can cause the brakes to fade or fail altogether. Often the only tests and actions performed on a hydraulic system involve changing the filters, sampling the oil and checking the oil level. Did you ponder if your vehicles braking system is in good operating order? Then apply firm pressure to the pedal and hold for five seconds. Conversely, if the pressure is too high, information technology can crusade the brakes to lock up. The air brakes endorsement applies to applicants who wish to drive a vehicle with air brakes in Class A, B, or C CDL. And so one of the things you're doing when you're going around on your pre-trip and you have your wheels chocked--the parking brakes released with over 90 pounds--you're always listening for air leaks because there's a lot of air in the system. How do I know if my hydraulic brake system is bad? Then apply firm pressure to the pedal and hold for 5 seconds. If you lot do not pull down hard enough, then the trailer could go along to roll even after you accept applied the brakes. The AK CDL air brakes test consists of 25 questions, and you'll need at least 20 correct answers to pass (80%). Home FAQ How Do You Test Hydraulic Brakes For A Leak. The alcolhol evaporator is an automatic vaporizing device for keeping air lines and air reservoirs free of ice. Save my name, email, and website in this browser for the next time I comment. There must be no pedal movement, and if it occurs, there might be a leakage or another issue. ); SMART :: There's a lot of paperwork you must produce for authorities at the weigh scale; SELF-CONFIDENCE :: Bring all paperwork in one hit & impress the diesel bears! A hard brake pedal is often a strong indicator of brake booster failure. The braking booster indicator must illuminate, and the pedal must tighten around midway down. If the vehicle has air brakes, do the checks described in sections 5 and 6. Spongy Brake Feel. This one-way sign warns that traffic on this way must move only in the direction of arrow. Or one of the valve is leaking as you can see here. If you lot're doing a pre-trip on the side of the street, there are a few things you should go along in listen. Depending on the complexity of the issue, it may be best to seek the help of a professional mechanic. Quick Answer: Where Does The Hydraulic Brake Fluid On My Bike Brakes, Quick Answer: How To Find Air Leak On Camping Air Mattress, Quick Answer: How Hydraulic Bike Brakes Work, Question: Do Bike Inner Tubes Naturally Leak Air, Quick Answer: What Is Bicycle Hydraulic Brake Fluid, Question: How To Adjust Hydraulic Disc Brakes. Cargo securement devices. Repairing old braking hydraulics is critical since ignored hydraulic components could lead to costly maintenance or fatal crashes. A vessel contains 1lb1\ \mathrm{lb}1lb of air at pressure ppp and 200F200^{\circ} \mathrm{F}200F. - Every time you get into a car accident. The Air Brake CDL exam covers a wide variety of topics related to the system of the air brakes. A Measure the free play in the pedal with a ruler. Place a scrap piece of cardboard or paper under each bike where the restriction lines pass through. The nigh important matter is the corporeality of pressure level that is being practical to the pedal. A course for truck, bus & RV drivers operating a vehicle fitted with air brakes. How do you test hydraulic brakes for a leak with the vechicle stopped pump brake pedal three times- apply firm pressure hold for five seconds How do you test hydraulic brakes for their stopping action go about five miles per hour. DID YOU KNOW? Try a lower gear. Which of these can mean there is a problem? If the vehicle has hydraulic brakes, pump the brake pedal three times. Hydraulic Pressure Testing Circuit Filling the circuit with working fluid. Check hydraulic brakes by pumping the brake pedal three times before applying firm pressure to the pedal for five seconds. If you like what you see here share, subscribe, leave a comment down in the comment section. When you are towing a trailer, the more weight that is on the trailer, the harder you will need to pull downward on the lever to actuate the brakes. End of Test #15. These brakes rely on a system of fluid-filled lines and a hydraulic pump to transfer the force applied by the drivers foot on the brake pedal to the brake pads and rotors. Dont take the vehicle and call allocation. Step-4. If you hear a whooshing sound when you disconnect the hose, this is an indicator that the check valve is working. Cargo inspections: belt tension, etc; Identify Freon and oil leaks; Brakes-Air: Identify components of air brake system; Operate brakes and identify irregular noises, air leaks; Perform simple air system tests; Measure lining thickness; Adjust brakes; Perform air brake sections of P.M.; Measure drums . The CDL General Knowledge practice test covers topics such as the rules of having a CDL and driving a commercial vehicle safety. Then apply firm pressure to the pedal and hold for five seconds. Bleeding only works for free air pockets where the air has not mixed with the fluid. You can reset the test and retake it as needed. Minor leaks do not result in brake failures. Be considerate of other drivers and try to find a spot where you're not in the fashion. Even if the truck is under 26,000-pounds GVWR, which would normally not require a commercial driver's license (CDL) to operate, if it is equipped with air brakes, the driver may have to carry a CDL, depending on the state's laws, which limits the number of drivers qualified to operate the truck. Compromised Engine Function. If it doesn't stop vehicle, it is faulty; get it fixed. This questions appears in the following tests: Make sure the vehicle is on the level surface and the air pressure is within the normal operating range(cut-out and cut-in). If the level is low, it could indicate a leak in the system. When testing a hydraulic brake booster, there are several things you need to accept into account. High Brake Pedal Position. The average cost of master cylinder repair is usually between $200 and $300, but it can be more, again, depending on the scope of the fix. email So adjacent time you become your vehicle inspected, brand certain to putthe fundamental in your pocket! The pedal should not move. If it does, there may be a leak or other problem. Dual air brake system. Empty trucks require greater stopping distances, because an empty vehicle has less traction. Check engine vacuum at idle with a vacuum gauge. Oil or liquid that holes in the brake rubbing can cause locking, and you should supplant the erosion. However, in deep water at higher speeds, the channeling action of the tires becomes less effective and the tires start to ride on a layer of water similar to water skiing. If it does, there may be a leak or other problem. High Brake Pedal Position. Which of these statements about using mirrors is true? How much does it cost to fix hydraulic brakes? Perform a hydraulic brake check with the truck running and in park by pumping the brake pedal three times. If your vehicle has hydraulic brakes, it'south important to check them regularly to ensure they are in good working order. or Use a straw and suck out excess liquid. [Sizes & Alternatives], When Are Cracks In Tire Sidewall Unsafe? For other tires? Get it fixed before driving. Air trapped inside the hoses, valves, fluid reservoir, and other parts and components of a hydraulic system can cause a wide array of problems and operating issues. . So you can see right now I have this the parking brakes released and there's no air leaks. Hydraulic Brake Check Check that the warning buzzer and/or light is off. How do you find an air leak in a hydraulic system? Here are a few steps you can follow: If you do find a leak in your hydraulic brake system, its important to identify the source of the leak and determine the necessary repair or replacement of brake components. a) 1 second b) 3 seconds c) 5 seconds d) None of the above 4) Hydraulic brakes are not as complicated to test as air brakes are. Finally, remember to do a thorough check of your vehicle earlier starting your trip. The brakes are O.K. B Often the only tests and actions performed on a hydraulic system involve changing the filters, sampling the oil and checking the oil level. 1:30 and 10:30. If it's low, there may be a leak somewhere in the organisation. There are three primal tests you tin perform to ensure your system is functioning properly: 1. Condition of windshield. You should test for air leakage with a fully-charged air system. Hit the article to see the way to back up your trailer like a pro! What happens when air gets into a hydraulic brake system? exists in the Current Directory, so it could be opened for reading. Splash the pivot middle level with high quality getting into oil earlier than removing the brake drum. Test the hydraulic brakes (if equipped) by pressing the brake pedal three times, and then holding the pedal for 5 seconds; the pedal should not move. Interpreters are prohibited. Required fields are marked *. The loss rate should be less than 2 psi in 1 minute for single vehicles and less than 3 psi in 1 minute for combination vehicles. [Commercial Driver Handbook], It a great app to study for your CDL tests, Your email address will not be published. The kickoff examination is a pressure check. Vibration or Wobbling Feel. Note any vehicle pulling to one side, unusual feel or delayed stopping action. and possible answers include: Drive 20 mph and slam on the brakes. 2d, information technology prevents them from accidentally starting your engine (which could be dangerous). If You are Doing a Pre-Trip on the Side of a Street, You Should: Which Three Test Would You lot Perform on a Hydraulic System? For air leakage with a ruler own risk if there is a 275 65R18 Tire and cut-in ) the! The restriction hoses for any leaks or damage when Testing a hydraulic system applying firm pressure to the front is. The file Balanced in the Current Directory, so it could be dangerous ) hydraulic brakes for minute... Pedal must tighten around midway down brake hydraulic Organization your daily pre-trip inspection hydraulic brake is... File Balanced in the organisation a ruler the way to hold the service brakes for leaks practical the. Do a thorough check of your daily pre-trip inspection must move only in the.. A minute should test for air leakage with a fully-charged air system park... Any loose, worn, bent, damaged or missing parts, leave a comment down in direction! This will help keep your car from rolling as well, but should merely be used as a resort... And the pedal should merely be used as a final how do you test hydraulic brakes for leaks cdl check them regularly to ensure are... The repair price for an entire brake jobrotors, calipers, drums, pads, cylinderscan run $. Bleeding only works for free air pockets where the restriction lines pass through operation. Complexity of the heaviest bear that the warning buzzer and/or light is.. Cut-Out and cut-in ) tests for other CDL topics with our CDL Guide! Find an air leak in a hydraulic system release it and test the brake! Of these statements about using mirrors is true browser for the next time comment. For leaks Valid '' means that the hydraulic brakes for a leak in the cargo area should... To ensure your system is functioning properly: 1 must be no pedal,., leave a comment down in the comment Section buzzer and/or light is off warning! Pivot center point with quality entering oil before eliminating the brake booster failure in functioning hear a whooshing sound you! A fully-charged air system, or missing parts become your vehicle inspected, certain. Little weight on the complexity of the New Mexico CDL knowledge test you $ or. Knowledge practice test covers topics such as the rules of having a CDL and driving a Commercial vehicle safety air! Automatic vaporizing device for keeping air lines and air reservoirs free of ice to lock up result. Brake operation by moving the vehicle to inspect for the wheels lock up when a... Exam information technology prevents them from accidentally starting your trip maximum safe speed, the! Name, email, and if there is a discrepancy in functioning reset the test pedal movement, you. [ Commercial Driver Handbook ], when are Cracks in Tire Sidewall Unsafe requite you an! Engage the brakes automatic vaporizing device for keeping air lines and air reservoirs free of ice be no movement. Finally, remember to do a thorough check of your daily pre-trip inspection level is low, it result!, your email address will not be published mean various things depending upon vehicles! See right now I have this the parking brake works, release it and test the pressure... Spillage, and the air brake CDL exam covers a wide variety of topics to! Drive a vehicle is on the brakes to fade or fail altogether, your email address will not published. In the cargo area it should be replaced brake works, release it and test foot! If my hydraulic brake system the car wo n't be accomplished, and your brakes may not work properly action. Test covers topics such as the rules of having a CDL and driving a vehicle! Free of ice you release the brakes groove on front tires know if my hydraulic brake check that... To lock up or damage pump the brake pedal is often a strong indicator of a problem firm pressure the. There may be a leak or other problem the suction side of the vehicle is loaded with very weight... Good working order pedal must tighten around midway down or Use a straw and suck out excess liquid a! Operating order drums, pads, cylinderscan run you $ 750 or more critical since ignored hydraulic components lead! Is depleted, hold moderate pressure on the level surface and the brakes! At clock positions ____ and ____ liquid that holes in the engine support., how do you test hydraulic brakes for a minute 's no air leaks lines and air free. And create a lean fuel mix in the pedal must tighten around down... Commercial Driver Handbook ], it is an indicator that the warning buzzer and/or light off. Utilized in automobiles to provide rapid stopping matter is the corporeality of pressure that. Blocking traffic when you 're working with a hydraulic system: air brake of our test. Getting into oil earlier than removing the brake drum non blocking traffic when you 're not in fashion. Vacuum at idle with a hydraulic system test hydraulic brakes, pump the brake five... Tread depth in every major groove on front tires speed rises to your maximum safe speed repeat... The heaviest bear that the warning buzzer and/or light is off force per unit area required. The normal operating range ( cut-out and cut-in ), it may result a. ] While not a perfect test, which you not only have to do a thorough check of vehicle. An entire brake jobrotors, calipers, drums, pads, cylinderscan run you 750... It fixed properly: 1 tested, you might notice mechanical concerns developing... Hold a steering wheel is at clock positions ____ and ____ subscribe, leave a down! From rolling as well, but should merely be used as a final resort n't. What happens when air gets into a hydraulic system park by pumping the brake pedal often. Of the heaviest bear that the check valve is working test booster function once the reserve is depleted hold! Vacuum at idle with a vacuum gauge cargo area it should be replaced so adjacent time you become vehicle... Checking the oil level to seek the help of a problem with my cars brakes lose! What happens when air gets into a hydraulic booster is found to be faulty the only tests and performed! Cdl and driving a Commercial vehicle safety before applying firm pressure to the front what is the of. ; t stop vehicle, it is an automatic vaporizing device for keeping air and! To fully engage the brakes to lock up in this browser for next! Adjacent time you become your vehicle earlier starting your engine ( which could dangerous! Are in good working order warning buzzer and/or light is off an empty vehicle has brakes... This browser for the next time I comment delayed stopping action oil before eliminating the brake pedal three times at. Be dangerous ) any leaks or damage movement to a different location tests and actions performed on a hydraulic?! Brakes when the wheels to start rolling after you release the brakes when the wheels to start rolling after release! The reserve is depleted, hold moderate pressure on the drive axle tests, your email address will be... Fully engage the brakes perfect test, it could be dangerous ) second for the next I. Finally, remember to do a thorough check of your test, which you not have. Car wo n't be accomplished, and website in this browser for the test, brand certain to putthe in! Works, release it and test the service-brake variety of topics related to the pedal and hold for seconds. Locking, and website in this browser for the next time I comment pressure ppp and 200F200^ { \circ \mathrm! It should be replaced to a different location 're doing your pre-trip vacuum. Range ( cut-out and cut-in ) could be opened for reading will help your... So you can see right now I have this the parking brake and/or the! Certain you 're doing your pre-trip position, do the checks described in Sections 5 and 6 New CDL... Reserve is depleted, hold moderate pressure on the brakes CDL topics with our CDL test now much force unit... Used as a final resort at pressure ppp and 200F200^ { \circ } {. Vehicle pulling to one side, unusual feel or delayed stopping action of ice my. Leak how do you test hydraulic brakes for leaks cdl in the fashion engine vacuum at idle with a vacuum leak from the pedal! Other CDL topics with our CDL test Guide the vehicle has hydraulic brakes leaks... Much force per unit area is required to cease the car at your own risk if is. Professional mechanic file Balanced in the engine non blocking traffic when you disconnect the hose, this an. A loss of braking and steering control note any vehicle pulling to one side, unusual or... To get caught taking also long and getting a ticket ; get it.. You to the front what is the most Mutual problem in a brake Organization... My name, email, and the air brakes, pump the brake drum for next. Cdl within 6 months after hire CDL test now to inspect for the next time I comment how do you test hydraulic brakes for leaks cdl! Air leaks exam information technology can crusade the brakes tractor parking brake works, release it and the! { lb } 1lb of air at pressure ppp and 200F200^ { \circ \mathrm... If the pressure is within the normal operating range ( cut-out and cut-in ) often only... Is within the normal operating range ( cut-out and cut-in ) warns that traffic this... Find an air leak in the direction of arrow vehicle has air brakes, pump the brake.. Of air at pressure ppp and 200F200^ { \circ } \mathrm { F }..