clutch GMC C-SERIES 1999 User Guide

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4-31
Power Take-Off (PTO) (If Equipped)
Before using a PTO, refer to the body builder's or
operator's instructions.
To engage a PTO:
1. Make sure the vehicle is stopped.
2. Shift the transmission into NEUTRAL (N) or
PARK (P), if equipped.
3. The brake or clutch pedal must be pressed and
released once before PTO can be enabled. Do not
hold the brake or clutch pedal down.4. The cruise control switch must be in ON prior to
engaging the PTO switch to enable PTO operation.
This sets the PTO base engine idle at 1200 rpm.
5. Use SET/COAST to change the engine speed to the
lower preset value of 1400 rpm. Use
RESUME/ACCEL to change the engine speed to the
upper preset value of 1800 rpm. You may toggle
between upper and lower by moving the switch
between SET/COAST and RESUME/ACCEL.
The PTO will become inoperative when any of the
conditions are changed or the CHECK GAGES light
comes on.
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5-33
5. Then replace the pressure cap. Be sure the arrows on
the pressure cap line up like this.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This
improves fuel economy and reduces fan noise. Under
heavy vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise.
This is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
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6-12 Tampering With Noise Control
System Prohibited
Federal law prohibits the following acts or the
causing thereof:
1. The removal or rendering inoperative by any person,
other than for purposes of maintenance, repair or
replacement, of any device or element of design
incorporated into any new vehicle for the purpose of
noise control, prior to its sale or delivery to the
ultimate purchaser or while it is in use; or
2. The use of the vehicle after such device or element
of design has been removed or rendered inoperative
by any person.
Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:

Removal of the noise shields or any
underhood insulation.Engine:

Removal or rendering engine speed governor (if
equipped) inoperative so as to allow engine speed to
exceed manufacturer specifications.
Fan and Drive:

Removal of fan clutch (if equipped) or rendering
clutch inoperative.

Removal of the fan shroud (if equipped).
Air Intake:

Removal of the air cleaner silencer.

Reversing the air cleaner cover.
Exhaust:

Removal of the muffler and/or resonator.

Removal of the exhaust pipes and exhaust
pipe clamps.
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6-37 Clutch Pedal Free Travel
If you have a manual transmission, your clutch will need
adjustment when pedal free travel gets down to about
1 1/4 inch (32 mm), as measured at the clutch pedal pad.
You should have 1 1/2 to 2 inches (38 to 51 mm) of
clutch pedal free travel. Your Maintenance Schedule has
more on this.
If your clutch ever needs service, be sure to use only
genuine GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see your Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
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6-39
ITEM NO. ITEM REMARKS
1 Brake Camshaft
, Brake Caliper
Rails (If Equipped)$One fitting each (apply sparingly). For caliper rails,
apply Aero Shell #5 Lubricant.
2 Steering Column Slip Joint* One fitting.
3 Steering Drag Link Ends One fitting at each end.
4 Steering Column U
-Joints One fitting each joint.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster
One fitting.
7 Brake Cam Roller Pins at interface
of pin and shoe
Apply engine oil.
8 Front Steering Knuckles One fitting each side, lower bushing (hand
-operated
grease gun only). Hand
-pack upper bearing.
9 Front Wheel Bearings Hand
-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads*
(Multi
-Leaf Only)Apply chassis lubricant.
12 Clutch Release Bearing* Cup or fitting.
13 Battery Terminal
(except ªSTº type)Keep coated with petroleum jelly.
14 Parking Brake Bell Crank*$ One fitting.
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6-70
Name Circuits Protected
HYD BRK Brake Pump Motor Relay
HYD BRK Brake Alarm ModuleName Circuits Protected
B/U IGN3 Fuel Filter Relay, Blower Motor
Relays, ABS Power Relay,
Back
-Up Lamps, Auxiliary Wiring
Relay, IGN 3 Relay, Power
Window Relay, Vehicle Interface
Module, Transmission
Temperature Gage
STOP Stoplamps
WASH/WIPE Windshield Wipers/Washer,
Accessory Relay
DOME/PNL Dome Lamp, Radio Receiver,
Instrument Panel Lights,
A/C Controller,
Headlamp/Seatbelt Module
BLOWER Blower Motor
A/C A/C Clutch Compressor,
A/C Controller
TRN/HAZ Turn Signals, Hazard Flashers
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7-5
Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be performed after 100,000 miles
(166 000 km) at the same intervals. The services shown
after 100,000 miles (166 000 km) should be performed
at those same intervals.
This vehicle has a computer that lets you know when to
change your engine oil. This is not based on mileage,
but on engine revolutions and engine operating
temperature. When the computer has calculated that the
oil needs changing, the Oil Life Indicator will indicate
that a change is necessary.
See ªFootnotesº at the end of this Maintenance Schedule
for further explanation of maintenance services and
Caterpillar

diesel application.
100 Miles (160 km)
Wheel stud nut service. (45)
500 Miles (800 km)
Wheel stud nut service. (45)
1,000 Miles (1 600 km)
Wheel stud nut service. (45)(46)
3,000 Miles (5 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Clutch pedal free travel service. (10)
Rear axle air shift motor service. (11)
6,000 Miles (10 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Chassis lubrication service (or every 6 months,
whichever occurs first). (12)
Lubricate door hinge pins and rollers with engine oil.
Wheels and tires service. (15)
Hydraulic brake service (or every 6 months,
whichever occurs first). (7)
Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)
Clutch pedal free travel service. (10)
9,000 Miles (15 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
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7-6 12,000 Miles (20 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Lubricate door hinge pins and rollers with engine oil.

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Clutch pedal free travel service. (10)

Throttle linkage service. (19)

Thermostatically controlled engine cooling
fan service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours,
whichever occurs first).
15,000 Miles (25 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Steering system service. (13)

Front and rear suspension service. (14)

Spring
-to-axle U-bolts and shackle bolts service. (16)

Exhaust system service (or every 6 months,
whichever occurs first). (3)(4)(17)

Air brake service (or every 6 months, whichever
occurs first). (39)
18,000 Miles (30 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Inspect door hinge pins and bushings and replace as
necessary. Lubricate door hinge pins and rollers with
engine oil.
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7-7

Replace air conditioning filter dryer (or every
18 months, whichever occurs first, and whenever
refrigerant charge is lost for any reason).

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic brake caliper service (or every 6 months,
whichever occurs first). (22)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Clutch pedal free travel service. (10)

Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first);
lubricate linkage.
21,000 Miles (35 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
24,000 Miles (40 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Lubricate door hinge pins and rollers with engine oil.

Wheel bearing (grease type) service (or every
24 months, whichever occurs first, and whenever
hubs are removed). (23)

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Clutch pedal free travel service. (10)

Throttle linkage service. (19)

Thermostatically controlled engine cooling
fan service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

Air intake system service (or every 24 months,
whichever occurs first). (4)(5)(24)

Thermostatically controlled air cleaner service
(or every 24 months, whichever occurs first).
(3)(4)(25)

(Continued)
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7-8 24,000 Miles (40 000 km) (Continued)

Evaporative Control System service (if equipped) (or
every 24 months, whichever occurs first). (3)(26)

Rear axle air shift motor service. (11)
Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours,
whichever occurs first).
Air brake chamber service (or every 2 months,
whichever occurs first). (41)
Trailer brake hand control valve service (or every
3 months, or 900 hours, whichever occurs first). (42)
27,000 Miles (45 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
30,000 Miles (50 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Chassis lubrication service (or every 6 months,
whichever occurs first). (12)
Replace fuel filter(s) (or every 12 months, whichever
occurs first). (3)Air cleaner filter replacement service (or every
24 months, whichever occurs first). (3)(4)(27)
Steering system service. (13)
Front and rear suspension service. (14)
Spring
-to-axle U-bolts and shackle bolts service. (16)
Exhaust system service (or every 6 months,
whichever occurs first). (3)(4)(17)
Air brake service (or every 6 months, whichever
occurs first). (39)
Lubricate door hinge pins and rollers with engine oil.
Wheels and tires service. (15)
Hydraulic brake service (or every 6 months,
whichever occurs first). (7)
Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)
Clutch pedal free travel service. (10)
Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first). (40)
33,000 Miles (55 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
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