[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-295591-105":59,"doc-detail-295591-en":131},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","air-brakes-practice-test-readiness-questions","Air Brakes Practice Test - Readiness Questions","","Air Brakes Practice Test provides CDL applicants with a multiple-choice review focused on core air-brake system safety, operation, and inspection requirements. The questions cover allowable air loss rates, warning-device activation thresholds, functions of valves such as one-way check valves and relay components, brake system types (service, parking, emergency), and principles like heat absorption and downgrade braking strategies. It also addresses alcohol evaporator purpose, gauge readings, foundation brake types, slack adjuster free-play checks, and emergency braking techniques.",{"@graph":69,"@context":123},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":20,"@type":76,"position":81},"https://docshare.wps.com/document/exam/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/air-brakes-practice-test-readiness-questions/295591/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/air-brakes-practice-test-readiness-questions/295591.png","ImageObject",300,407,{"name":92,"@type":93},"Emma Wilson","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-04","2026-09-18",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",13,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"What is the maximum allowable air loss for a straight truck or bus with the engine off and brakes applied?","Question",{"text":113,"@type":114},"It should not be more than 1 psi in 60 seconds.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"At what air pressure threshold must the warning device come on when service air tanks fall?",{"text":118,"@type":114},"The warning device should come on when pressure falls below 60 psi.",{"name":120,"@type":111,"acceptedAnswer":121},"What is the purpose of the engine retarder?",{"text":122,"@type":114},"The purpose of engine retarders is to help slow the vehicle while driving and reduce brake wear.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},295591,1789720505,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":19,"category_name":20,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":34,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":130,"read_time":144},3848291630094,"https://eur-avatar.wpscdn.com/davatar_085a072bc5b1113ac321206ff7593b45","Air Brakes Practice Test  \nDirections: Read each question carefully and select the answer that best answers the question.  \nNOTE: This test must be taken by all CDL applicants desiring to operate equipment with air brakes.  \n1. Which of the following is okay to find in the air brake system?  \nA. Oil  \nB. Air  \nC. Water  \nD. All of the above  \n2. Air loss in a single vehicle (not a combination unit) should not be more than   with the engine off and the brakes on.  \nA. 1 psi in 30 seconds  \nB. 1 psi in one minute  \nC. 2 psi in 45 seconds  \nD. 3 psi in one minute  \n3. The vehicle must have a warning device which comes on when the air pressure in the service air tanks falls below:  \nA. 40 psi  \nB. 50 psi  \nC. 60 psi  \nD. 80 psi  \n4. If the air system should develop a leak, what will keep air in the air tanks?  \nA. The governor  \nB. The tractor protection valve  \nC. The emergency relay valve  \nD. The one-way check valve  \n5. Which brake system applies and releases the brakes when the driver uses the brake pedal?  \nA. The emergency brake system  \nB. The service brake system  \nC. The parking brake system  \nD. None of the above  \n6. When using the parking brakes or emergency brakes, what type of pressure is being used?  \nA. Fluid pressure  \nB. Spring pressure  \nC. Air pressure  \nD. Any of the above  \n7. The air loss rate for a straight truck or bus with the engine off and the brakes applied should not be more than:  \nA. 1 psi in 60 seconds  \nB. 1 psi in one minute  \nC. 2 psi in 45 seconds  \nD. 3 psi in one minute  \n8. Air brake equipped vehicles must have:  \nA. At least three air tanks  \nB. A hydraulic braking system, in case the air system fails  \nC. An air pressure gauge, to show the pressure available for braking  \nD. An air application gauge, to show air used by the brake chambers for braking  \n9. Which of the following statements about brakes is true?  \nA. The heavier a vehicle or the faster it is moving, the more heat the brakes have to absorb to stop it  \nB. Brakes have more stopping power when they get very hot  \nC. Brake drums cool very quickly  \nD. All of the above  \n10. Three different systems are found on modern air brake systems; service brakes, parking brakes, and:  \nA. Emergency brakes  \nB. Foot brakes  \nC. S-cam brakes  \nD. Drum brakes  \n11. The purpose of engine retarders is to:  \nA. Provide emergency brakes  \nB. Help slow the vehicle while driving and reduce brake wear  \nC. Apply extra braking power to the non-drive axles  \nD. Help prevent skids and slides  \n12. To use the stab braking technique during emergency braking, you:  \nA. Pump the brake pedal rapidly and lightly  \nB. Brake hard with the pedal until the wheels lock, then get off the brakes until the wheels begin to roll again  \nC. Brake hard with the pedal until the wheels lock, then get off the brakes for as long as the wheels were locked  \nD. Brake hard with the pedal and hand valve until you stop  \n13. If your vehicle has an alcohol evaporator, it’s there to:  \nA. Get rid of alcohol that condenses in the air tanks  \nB. Let the driver skip the daily tank draining  \nC. Increase tank pressure the way superchargers boost engines  \nD. Reduce the risk of ice in the air brake valves in cold weather  \n14. If your vehicle is equipped with an alcohol evaporator, every day during the winter you should:  \nA. Check the alcohol level and fill if necessary  \nB. Change the alcohol with a new bottle  \nC. Oil the system with 5 wt. oil  \nD. Drain any alcohol that has accumulated  \n15. The air supply pressure gauge shows the driver how much pressure:  \nA. Has been used in this trip  \nB. Is available in the air tanks  \nC. Is being sent to the brake chambers  \nD. None of the above  \n16. The most common type of foundation brake found on heavy commercial motor vehicles is:  \nA. Disc  \nB. Wedge and drum  \nC. S-cam drum  \nD. None of the above  \n17. A straight truck or bus air brake system cannot leak more than how many psi per minute with the engine off and the brakes released?  \nA","cbCaiakDgIfS6NHd","https://ap.wps.com/l/cbCaiakDgIfS6NHd","pdf",105611,"English","# Air Brakes Practice Test\n## System Fundamentals and Components\n## Pressure, Gauges, and Leakage Limits\n## Brake Operation and Techniques\n## Valves, Alcohol Evaporators, and Inspection Procedures\n## Downgrade Control and Emergency Stops","[{\"question\":\"What is the maximum allowable air loss for a straight truck or bus with the engine off and brakes applied?\",\"answer\":\"It should not be more than 1 psi in 60 seconds.\"},{\"question\":\"At what air pressure threshold must the warning device come on when service air tanks fall?\",\"answer\":\"The warning device should come on when pressure falls below 60 psi.\"},{\"question\":\"What is the purpose of the engine retarder?\",\"answer\":\"The purpose of engine retarders is to help slow the vehicle while driving and reduce brake wear.\"}]","Air Brakes Practice Test - Readiness Questions | PDF",18]