Pennsylvania CDL Air Brakes case studies
Pennsylvania CDL Air Brakes · Put your knowledge to work in context.
The Pennsylvania CDL Air Brakes knowledge test is the written endorsement exam a commercial driver takes when the vehicle they will operate is equipped with air brakes. In Pennsylvania, an air brake restriction applies to your CDL if you pass the general knowledge test but not the air brakes test, so clearing this exam is what removes that restriction and lets you legally drive air-brake-equipped trucks, buses, and tractor-trailers. The Pennsylvania CDL Air Brakes case studies are 5 cases and about 2,487 words.
1Primary Circuit Pressure Loss on a Loaded Tractor-Trailer
Driving a 2020 Freightliner Cascadia pulling a loaded 53-foot van, gross combination weight 78,000 lb, on I-81 near Hazleton. The tractor has a dual air brake system with separate primary and secondary gauges.
528 words, about 3 min2Pre-Trip Leak Test on a Combination Vehicle
During a pre-trip inspection of a 2018 Kenworth T680 tractor with a 53-foot dry van, the driver builds air pressure until the governor cuts out at 125 psi. With the engine off and the parking brake released, the primary gauge drops 3 psi in one minute and the secondary drops 2 psi.
625 words, about 3 min3Pressure Loss and Hot Brakes on a Steep Grade
A driver of a 2016 Volvo VNL with a loaded dump trailer, gross weight 96,000 lb, descends a 7% grade on PA-44 for 2.5 miles. The speed limit is 45 mph.
459 words, about 2 min4Parking Brake Rollback on a Loaded Delivery Truck
A driver parks a 2019 International DuraStar 26-foot box truck with air brakes, loaded to 25,500 lb, on a 6% uphill driveway with no curb. The driver sets the parking brake, places the transmission in neutral, releases the service brake, and the truck rolls backward about 3 feet before stopping.
452 words, about 2 min5Brake Fade on a Long Interstate Descent
A driver of a 2021 Peterbilt 579 with a 53-foot refrigerated trailer, gross 80,000 lb, descends a 6% grade for 4 miles on I-80 near Bloomsburg. The driver wants to hold 55 mph and uses light, continuous brake pressure.
423 words, about 2 min