operators_manual

What is an Air
Compressor?
Air systems have an air compressor that
provides compressed air to the system.
All compressors, regardless of make or
model, run continuously while the engine is
running. System pressure is controlled by
the governor. The governor acts in
conjunction with the unloading mechanism
in the compressor cylinder block to start
and stop compression of air. The
compressor is unloaded when the system
pressure reaches 120 psi (827 kPa) and
compression is reestablished when system
pressure falls to 100 psi (690 kPa).
Preventive Maintenance
The following service checks are provided
for your information only and should be
performed by a certified mechanic. Contact
your dealer or the engine manufacturer's
Maintenance Manual for further information
on servicing air compressors. After
completing any repairs to the air system,
always test for air leaks, and check the
brakes for safe operation before putting the
vehicle in service. Below is a list of areas
to maintain for the air compressor:
• Inspect compressor air filter
element, if so equipped, and
replace element if clogged. Check
compressor mounting and drive for
alignment and belt tension. Adjust
if necessary.
• Remove compressor discharge
valve cap nuts and check for
presence of excessive carbon. If
excessive carbon is found, clean or
replace the compressor cylinder
head. Also, check compressor
discharge line for carbon, and
clean or replace the discharge line
if necessary.
• Disassemble compressor and
thoroughly clean and inspect all
parts. Repair or replace all worn or
damaged parts, or replace
compressor with a factory
exchange unit.
CAUTION
When draining the engine cooling sys-
tem is required, to prevent damage
from freezing, the compressor must al-
so be drained at the cylinder head and
block. Engine damage could occur if
the cooling system is not periodically
drained and maintained. See Cooling
System for further information.
Brake System
General information about your vehicle's
brake system and its components.
To operate your vehicle safely and
profitably, you need some understanding of
its brake systems. For more on brakes, see
the Index, under Brakes.
WARNING
Do not work on the brake system with-
out the parking brake set and wheels
chocked securely. If the vehicle is not
secured to prevent uncontrolled vehi-
cle movement, it could roll and cause
death, serious personal injury or dam-
age to the vehicle.
MAINTENANCE - What is an Air Compressor?
Y53-6047-2HEN (03/18) 213
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