Maintenance Information - "c", "k", "r" & "v" Series GMC Pickup R1500

MODEL IDENTIFICATION

Note. For the 1988-91 model years General Motors manufactured two (2) different truck models; the "R" & "V" models (similar to the older 1973-1987 model trucks), and the new "C" & "K" models. The new models use the old model designations except for payloads (Was: C10/15, Now: C1500).

Note. The Crew-Cab Bonus Cab (Single Rear Wheel) and Dually are only available (1988-91) in "R" & "V" models; and all Extended Cabs only in the new "C" & "K" design. From 1992 all trucks are new design "C" & "K" models.

Scheme 1

VIN LOCATION

The Vehicle Identification Number (VIN) is located on the left side of the dash panel at the base of the windshield. The VIN chart explains the code characters.

SERVICE PARTS IDENTIFICATION LABEL

Label is located inside glove box door and has the vehicle's VIN, wheelbase, paint information, and a list of all production options and special equipment.

VIN CODE ID EXPLANATION

Numbers preceding the explanations in the legend below refer to the sequence of characters as listed on VIN identification label. See VIN example below.

VIN Code ID Explanation. Scheme 2

SEVERE & NORMAL SERVICE DEFINITIONS

Note. Use the Severe Service schedule if the vehicle to be serviced is operated under ANY (one or more) of these conditions

Service is recommended at mileage intervals based on vehicle operation, emission classification, and Gross Vehicle Weight Rating (GVWR, VIN Position 4). Emission classification is identified by engine VIN code (except diesel-powered vehicles). Manufacturer's Schedules identify items to be serviced based on type of operation. Service schedules are based on the following primary operating conditions

Severe Service

1. Short Trips (4 Miles Or Less)
2. Freezing Temperatures
3. Towing Or Heavily Loaded
4. Severe Dust Conditions
5. Hot Weather, Stop-And-Go Driving
6. Extensive Idling Conditions (Taxi Or Delivery Type Service)

Normal Service

1. No Severe Service Operating Conditions

Scheme 3

Note. For more information regarding lifting and hoisting refer to the JACKING & HOISTING article in the WHEEL ALIGNMENT section.

Scheme 4

DRAINING, FLUSHING AND REPLACEMENT OF DIESEL COOLANT

1. Open the air bleed valve in the engine coolant outlet (thermostat housing). (Scheme 5)
2. Fill the surge tank bottle until coolant comes out of the air bleed valve.
3. ON VEHICLES WITH REAR HEATER, close the air bleed valve. Start the engine and bring the engine speed to 2000 RPM for 2 to 3 minutes to flush any air for rear heater. Shut off the engine and open the air bleed valve. Fill the surge tank until coolant comes out the air bleed valve.
4. Close the air bleed valve and install pressure cap on the surge tank.
5. Monitor the cold coolant level in the surge tank. Add coolant as needed to bring the coolant level to the "Full Cold" mark.
6. Verify there are no leaks.

Scheme 5

Note. For more information regarding Diesel Idle Speed Adjustments refer to the ADJUSTMENTS - 6.5L DIESEL article in the ENGINE PERFORMANCE section.

DRAINING FUEL FROM WATER/FUEL SEPARATOR (DIESEL)

1. Turn off engine and block drive wheels.
2. Remove fuel filler cap(s) to release any pressure or vacuum in the vehicle fuel tank(s).
3. Place a suitable container under the filter drain hose.
4. Open the drain valve. (Scheme 6)
5. Start engine and allow to idle for 1 to 2 minutes or until clear fuel is observed.
6. Close the drain valve and stop the engine.
7. Replace fuel filler cap(s).
8. Dispose of drained mixture in a proper manner.

Scheme 6

Note. For more information regarding Diesel Idle Speed Adjustments refer to the ADJUSTMENTS - 6.5L DIESEL article in the ENGINE PERFORMANCE section.

CHANGING FUEL FILTER (DIESEL)

1. Turn off engine and block drive wheels.
2. Remove fuel filler cap(s) to release any pressure or vacuum in the vehicle fuel tank(s).
3. Place a suitable container under the filter drain hose.
4. Start engine and open the drain valve. (Scheme 6)
5. Once fuel begins to flow from the drain hose open the air bleed valve on the top of fuel filter housing. (Scheme 7)
6. Stop the engine.
7. After all fuel has drained from filter housing, close the fuel drain valve (Scheme 6), and the air bleed valve. (Scheme 7).
8. Dispose of drained mixture in a proper manner.
9. Loosen the element nut on the top of the fuel filter housing. (Scheme 7) An oil filter type wrench may be used.
10. Remove housing cap and lift out old fuel filter element.
11. Verify filter housing and all mating surfaces are free of any water or other contamination. Some clean fuel may be left in housing, as it will be absorbed by the new filter element.
12. Install new fuel filter by aligning the widest key slot located under the element assembly cap with the widest key in the housing.
13. Push the element assembly downward until the mating surfaces make contact.
14. Install and tighten element nut by hand.
15. Bleed air from fuel/water separator as follows.
16. Open air bleed valve on top of filter housing (Scheme 7).
17. Connect hose to the air bleed valve on the top of the filter housing (Scheme 7).
18. Disconnect the fuel injection pump shutdown solenoid (pink wire) located on the fuel injection pump. (Scheme 8)
19. Crank the engine in 10 to 15 second intervals until clear fuel is observed at the air bleed hose (Wait 1 minute between cranking intervals to avoid overheating the starter).
20. Close the air bleed valve.
21. Connect the shutdown solenoid wire and reinstall fuel filler cap(s).
22. Start the engine and allow to idle for 5 minutes.
23. Check fuel filter assembly for leaks.
24. Dispose of drained mixture in a proper manner.

Scheme 7

Scheme 8

STARTING OUT OF FUEL DIESEL

1. Add 5 gallons of diesel fuel to fuel tank.
2. Open air bleed valve on top of filter housing (Scheme 7).
3. Connect hose to the air bleed valve on the top of the filter housing (Scheme 7).
4. Place a suitable container under the filter drain hose.
5. Crank the engine in 10 to 15 second intervals until clear fuel is observed at the air bleed hose (Wait 1 minute between cranking intervals to avoid overheating the starter). CAUTION: If engine starts during step #5, stop engine and close air bleed valve before attempting restart.
6. Close the air bleed valve.
7. Crank the engine in 10 to 15 second intervals until the engine starts. (Wait 1 minute between cranking intervals to avoid overheating the starter).

Scheme 9

Scheme 10

Note. For more information regarding Diesel Idle Speed Adjustments refer to the ADJUSTMENTS - 6.5L DIESEL article in the ENGINE PERFORMANCE section.

Scheme 11

Note. For more information regarding CDVR testing and service refer to the SYSTEM/COMPONENT TESTS - 6.5L DIESEL article in the ENGINE PERFORMANCE section.

Scheme 12

Scheme 13

Scheme 14

Note. For more information regarding EGR system service refer to the EGR FUNCTION TESTING article in the ENGINE PERFORMANCE section.

BRAKE SERVICE INFORMATION

Note. For more information regarding brake system service refer to the BRAKE SYSTEM article in the BRAKES section.

Scheme 15

Scheme 16

Scheme 17

Scheme 18

AXLE & TRANSMISSION IDENTIFICATION

Note. For more information regarding Axle identification refer to the DRIVE AXLE RATIO IDENTIFICATION article in the DRIVE AXLES section.

Note. For more information regarding Automatic Transmission ID refer to the TRANSMISSION OIL PAN GASKET ID article in the AUTOMATIC TRANS SERVICE section.

WHEEL & TIRE SPECIFICATIONS

Wheel and tire information can be found on the decal attached to rear of driver's door.

Scheme 19

Scheme 20

Scheme 21

WHEEL TORQUE

Tighten the lug nuts firmly to torque specified in the wheel lug nut tightening table using patterns (Scheme 21)

WHEEL LUG NUT TORQUE SPECIFICATIONS

BATTERY SPECIFICATIONS

REAR WHEEL ANTI-LOCK BRAKE SYSTEM

The anti-lock brake system contains electronic equipment that can be susceptible to interference caused by improperly installed or high output radio transmitting equipment. Since this interference could cause the possible loss of the anti-lock braking capability, such equipment should be installed by qualified professionals.

On models equipped with anti-lock brake systems, ALWAYS observe the following cautions

1. DO NOT attempt to bleed hydraulic system without first referring to the appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES Section.
2. DO NOT mix tire sizes. As long as tires remain close to the original diameter, increasing the width is acceptable. Rolling diameter must be identical for all 4 tires. Some manufacturers recommend tires of the same brand, style and type. Failure to follow this precaution may cause inaccurate wheel speed readings.
3. Use ONLY recommended brake fluids. DO NOT use silicone brake fluids in an ABS-equipped vehicle.

AXLE FLUID

REPLACING BLOWN FUSES

Before replacing a blown fuse, remove ignition key, turn off all lights and accessories to avoid damaging the electrical system. Be sure to use fuse with the correct indicated amperage rating. The use of an incorrect amperage rating fuse may result in a dangerous electrical system overload.

BATTERY WARNING

BRAKE PAD WEAR INDICATOR

Indicator will cause a squealing or scraping noise, warning that brake pads need replacement.

BRAKE PAD REPLACEMENT

CATALYTIC CONVERTER

To prevent catalytic converter overheating, DO NOT allow engine to idle for more than 20 minutes.

COOLANT (PROPYLENE-GLYCOL FORMULATIONS)

To avoid possible damage to vehicle use only ethylene-glycol based coolants with a mixture ratio from 44-68% anti-freeze. DO NOT use 100% anti-freeze as it will cause the formation of cooling system deposits. This results in coolant temperatures of over 300° F (149°C) which can melt plastics. 100% anti-freeze has a freeze point of only -8° F (-22°C).

DIESEL FUEL ANTI-FUNGAL ADDITIVES

DIESEL FUEL CONTAMINATION

DIESEL FUEL REQUIREMENTS

Note. A Diesel Fuel #1 & #2 combination (Blended Fuel) may be used, and is recommended for mild winter driving.

JUMP STARTING (DIESEL)

STARTING FLUID USE (DIESEL)

ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS

FUEL SYSTEM SERVICE

HALOGEN BULBS

RADIATOR FAN

WARRANTY INFORMATION

FUSE PANEL LOCATION

The fuse block is located behind a cover in the dash to the left of the steering column.

Scheme 22

Fuse & Circuit Breaker Identification

1. 1 - Ints-Lps 5 Amp - Instrument Panel Lights, Headlight Warning Buzzer, Rear Defogger Switch Light
2. 2 - Pwr-Accy 30 Amp (Circuit Breaker) - Power Door Locks, Rear Defogger
3. 3 - Horn-Dim 20 Amp - Horn, Dome & Glove Box Lights, Clock, Courtesy Lights, Lift Gate Release Solenoid, Cigarette Lighter
4. 4 - Ign-Gau 20 Amp - Ignition, Gauges, Rear Defogger Relay, Automatic Transmission Converter Clutch, Cruise Control
5. 5 - Choke 20 Amp - Choke
6. 6 - Stop-Haz 15 Amp - Stoplights, Hazard Warning Lights
7. 7 - T/L-Ctsy 20 Amp - Light Switch, Taillights & Parking Lights
8. 8 - Turn-B/U 15 Amp - Turn Signal Lights, Back-Up Lights
9. 9 - Htr-A/C 25 Amp - Heating & A/C
10. 10 - Radio 15 Amp - Radio
11. 11 - ECM B 10 Amp - Electronic Control Module
12. 12 - ECM I 10 Amp - Electronic Control Module
13. 13 - Pwr Wdo 30 Amp (Circuit Breaker) - Power Windows
14. 14 - Wiper 25 Amp - Windshield Wipers & Washers
15. 15 - Crank 3 Amp

Scheme 23

Fuse & Circuit Breaker Identifiaction

1. 1 - Choke 20 Amp - Electric Choke
2. 2 - Htr-A/C 20 Amp - Heater & A/C, Alternator Gauge
3. 3 - Aux-Htr-A/C 25 Amp - Auxiliary Heater & Rear A/C
4. 4 - Gau/Idle 20 Amp - Warning Gauges, Idle Stop Solenoid, Warning Lights, Diesel Glow Plugs Relay (Diesel Engines), Diesel Fuel Heater (Diesel Engines)
5. 5 - Radio 15 Amp - Radio, Automatic Transmission (MD8), Auxiliary Battery
6. 6 - Stop-Haz 15 Amp - Hazard Flasher, Stoplights
7. 7 - Ign 20 Amp - Tachometer, Diesel Warning Lights, Cruise Control, Auxiliary Fuel Tank, 4-Wheel Drive Indicator Light, Rear Window Defogger, Automatic Trans. (M40)
8. 8 - T/L-Ctsy 20 Amp - Courtesy Lights, Taillights & Parking Lights
9. 9 - Wiper 25 Amp - Windshield Washer/Wiper
10. 10 - Turn-B/U 15 Amp - Back-Up Light Switch, Turn Signal Flasher
11. 11 - Horn-Dim 20 Amp - Horn, Cargo & Dome Lights, Headlight Warning, Cigarette Lighter, Clock
12. 12 - Inst-Lps 5 Amp - Instrument Panel Lights, Light Switch Rheostat, Headlight Warning, Rear Window Defogger Switch Light
13. 13 - Wdo 30 Amp (Circuit Breaker) - Power Tailgate Window, Power Windows
14. 14 - Pwr-Accy 30 Amp (Circuit Breaker) - Power Tailgate Window (Rear Switch), Power Door Locks, Rear Defogger