ASE T4 Brakes (Medium/Heavy Truck) case studies
ASE T4 Brakes (Medium/Heavy Truck) · Put your knowledge to work in context.
T4 is one of the T Series (T1–T8) Medium-Heavy Truck Certification Tests offered by the National Institute for Automotive Service Excellence. ASE describes the T Series as designed "to identify and recognize those Medium and Heavy Truck Technicians who can demonstrate knowledge of the skills necessary to diagnose, service, and repair different systems of Class 4 through Class 8 trucks and tractors." T4 is the brakes test in that series, and it is aimed at working technicians who service medium- and heavy-duty trucks and tractors rather than light vehicles - the light-truck brake content lives in the A Series instead. The ASE T4 Brakes (Medium/Heavy Truck) case studies are 5 cases and about 2,655 words.
1Slow Air Build on a Class 8 Tractor
A 2016 Class 8 tractor with a Cummins ISX and a Bendix twin-cylinder compressor comes in with a slow air build complaint. Shop temperature is 18°F.
537 words, about 3 min2Long Pushrod Stroke and a Seeping Wheel Seal
A 2013 Class 7 straight truck has 16.5 × 7 in S-cam drum brakes on the front axle and automatic slack adjusters. The complaint is a right-front brake pull and a left-front pushrod stroke that measures 2 1/4 in after a manual adjustment; the vehicle limit is 2 in.
550 words, about 3 min3Intermittent ABS and ATC Lamp After Wheel Seal Service
A 2017 Class 8 tractor with 4S/4M ABS and ATC is in for an intermittent ABS lamp and an ATC lamp that stays on. The fault code is for the right rear wheel speed sensor.
562 words, about 3 min4Low, Spongy Pedal After Caliper Replacement
A 2015 medium-duty truck with four-wheel disc brakes, hydro-boost, and ABS comes in after another shop replaced both front calipers and hoses. The complaint is a low, spongy pedal.
512 words, about 3 min5Spring Parking Brake Will Not Release on One Side
A 2014 Class 8 tractor with rear spring parking brakes will not release the left rear brake. With the dash park valve released (driving position), the left rear wheel drags and the left spring brake pushrod remains extended.
494 words, about 2 min