Heavy Duty Truck Systems – Chapter 4 – Preventative Maintenance – Lecture Summary &
Practice Questions
What are S-cam type foundation brakes mounted to? - ✔✔spider
In a truck air brake system, which sub-circuit is primarily responsible for actuating front axle
service brakes when the system is functioning normally? - ✔✔secondary circuit
What service braking is actuated by the primary circuit on a typical tandem drive axle, air brake
equipped tractor? - ✔✔drive axle brakes
All of the following are reasons to keep accurate records and documentation, except: - ✔✔To
ensure the technician dose his or her job
A good PM program can reduce overall maintenance cost by _________ - ✔✔eliminating
repairs caused by dirt, water, and other contaminants
Technician A says you should begin troubleshooting a rough running engine by removing the
injectors and looking for signs of fouling. Technician B says you should perform primary engine
checks on filters, operating pressures, and engine timing before disassembling any major
system. Who is right? - ✔✔B only
If a high sulfur diesel fuel (.05% or more) is being burned, the oil change interval must be
_________ - ✔✔decreased
A cylinder compression check should be performed when the following problems exist, EXCEPT:
- ✔✔no cranking
Technician A says that oil in the air system is ok, it will help lube the air valves. Technician B says
oil traces in the air tanks is normal for diesel engines. Who is right? - ✔✔B only
Practice Questions
What are S-cam type foundation brakes mounted to? - ✔✔spider
In a truck air brake system, which sub-circuit is primarily responsible for actuating front axle
service brakes when the system is functioning normally? - ✔✔secondary circuit
What service braking is actuated by the primary circuit on a typical tandem drive axle, air brake
equipped tractor? - ✔✔drive axle brakes
All of the following are reasons to keep accurate records and documentation, except: - ✔✔To
ensure the technician dose his or her job
A good PM program can reduce overall maintenance cost by _________ - ✔✔eliminating
repairs caused by dirt, water, and other contaminants
Technician A says you should begin troubleshooting a rough running engine by removing the
injectors and looking for signs of fouling. Technician B says you should perform primary engine
checks on filters, operating pressures, and engine timing before disassembling any major
system. Who is right? - ✔✔B only
If a high sulfur diesel fuel (.05% or more) is being burned, the oil change interval must be
_________ - ✔✔decreased
A cylinder compression check should be performed when the following problems exist, EXCEPT:
- ✔✔no cranking
Technician A says that oil in the air system is ok, it will help lube the air valves. Technician B says
oil traces in the air tanks is normal for diesel engines. Who is right? - ✔✔B only
