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Get Full Access Automotix DIY provides automotive consumers and do it yourselfers; the most comprehensive repair information about 1991 GMC K1500 Pickup car and truck repair procedures including GMC engine diagrams, wiring diagrams, repair work estimating measures, technical service bulletins, auto body work guidance, starter & alternator replacement procedures, serpentine belt replacement procedures, radiator & hose replacement procedures, tune-up & drivability specifications, quick lube illustrations, preventive maintenance guide, engine light reset instructions, parts removal and install procedures, fuel filter replacement directions, component location diagrams, air filter locations & replacement instructions, a/c system specifications, and general auto service procedures. You don't have to be a car mechanic or technician to know how to fix your 1991 GMC K1500 Pickup automobile. Try the Automotix DIY solution today!
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We have info for following modifications of 1991 GMC K1500 Pickup

  • 1991 GMC K1500 Pickup Sierra 4.3 V6 GAS, CID:262, Fuel Injection, Aspiration:262, Engine VIN:, Desg:Z
  • 1991 GMC K1500 Pickup Sierra 5.0 V8 GAS, CID:305, Fuel Injection, Aspiration:305, Engine VIN:, Desg:H
  • 1991 GMC K1500 Pickup Sierra 5.7 V8 GAS, CID:350, Fuel Injection, Aspiration:350, Engine VIN:, Desg:K
  • 1991 GMC K1500 Pickup Sierra 6.2 V8 DIESEL, CID:379, Fuel Injection, Aspiration:379, Engine VIN:, Desg:C
  • 1991 GMC K1500 Pickup Sierra XC 4.3 V6 GAS, CID:262, Fuel Injection, Aspiration:262, Engine VIN:, Desg:Z
  • 1991 GMC K1500 Pickup Sierra XC 5.0 V8 GAS, CID:305, Fuel Injection, Aspiration:305, Engine VIN:, Desg:H
  • 1991 GMC K1500 Pickup Sierra XC 5.7 V8 GAS, CID:350, Fuel Injection, Aspiration:350, Engine VIN:, Desg:K
  • 1991 GMC K1500 Pickup Sierra XC 6.2 V8 DIESEL, CID:379, Fuel Injection, Aspiration:379, Engine VIN:, Desg:C

BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

POWER BRAKE UNITS, GENERAL MOTORS -> Bendix Brake Boosters -> HYDRO-BOOST II -> BLEEDING BOOSTER -> CLEANING & INSPECTION -> DESCRIPTION -> DISASSEMBLE & ASSEMBLE
Vehicle: 1991 GMC K1500 Pickup Sierra XC 5.7 V8 GAS

DESCRIPTION

Hydro-Boost II is an hydraulically operated power brake booster. The hydraulic brake booster consists of an open center spool valve and an hydraulic cylinder combined into a single housing. The power steering pump provides the hydraulic fluid pressure to operate both the power brake booster and the power steering gear.

A dual master cylinder is bolted to the brake booster and is operated by a pushrod projecting from the booster cylinder bore.

The Hydro-Boost II also has an accumulator system which stores sufficient fluid under pressure to provide one power assisted brake...

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BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

ANTI-LOCK BRAKES, GENERAL MOTORS -> Four Wheel Anti-Lock Brake System -> DESCRIPTION
Vehicle: 1991 GMC K1500 Pickup Sierra 5.0 V8 GAS

This braking system Fig. is designed to reduce the occurrence of wheel lock-up during severe braking conditions. To accomplish this function, the system regulates hydraulic brake line pressure by using an Electronic Hydraulic Control Unit (EHCU) module. This control module has two types of valves. Isolation valves which maintain pressure to each front wheel separately and rear wheels combined. Dump valves which dump pressure to each front wheel separately and rear wheels combined. These valves are controlled by a microcomputer which is part of the EHCU module. During a severe brak...

CLICK HERE TO GET FULL ACCESS TO 1991 GMC K1500 Pickup BRAKE SERVICE PROCEDURES

BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

HYDRAULIC BRAKE SYSTEMS, GENERAL MOTORS -> SYSTEM SERVICE -> BLEEDING BRAKES -> BLEEDING MASTER CYLINDER -> BLEEDING PARKING BRAKE -> Flushing Hydraulic System -> Manual Bleeding -> Pressure Bleeding
Vehicle: 1991 GMC K1500 Pickup Sierra 5.0 V8 GAS

BLEEDING BRAKES

Manual Bleeding
  • If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off.
  • Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure.
  • If master cylinder is suspected to have air in the bore, it must be bled first, as follows:
    • Disconnect forward brake pipe connection at master cylinder.
    • Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port.
    • Connect and tighten forward...

CLICK HERE TO GET FULL ACCESS TO 1991 GMC K1500 Pickup BRAKE SERVICE PROCEDURES

BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

ANTI-LOCK BRAKES, GENERAL MOTORS -> Rear Wheel Anti-Lock Brake System -> SYSTEM SERVICE -> ELECTRONIC CONTROL UNIT (ECU) -> Except G, R, P & V Models -> G, R, P & V Models -> ISOLATION/DUMP VALVE ASSEMBLY -> SPEED SENSOR -> SPEEDOMETER CALIBRATION
Vehicle: 1991 GMC K1500 Pickup Sierra XC 5.0 V8 GAS

ELECTRONIC CONTROL UNIT (ECU)

Do not touch electrical connections and pins or allow them to come into contact with brake fluid.

  • Disconnect battery ground cable.
  • Disconnect electrical connectors from ECU.
  • Pry up tab at rear of ECU and remove unit toward front of vehicle.
  • Slide unit into bracket until tab locks into hole.
  • Inspect electrical connectors for brake fluid contamination, clean with alcohol as needed, then connect electrical connectors to ECU.

ISOLATION/DUMP VALVE ASSEMBLY

  • Disconnect brake lines from control valve, the plug lines and open fittings.
  • Remove bolts (25) securing...

CLICK HERE TO GET FULL ACCESS TO 1991 GMC K1500 Pickup BRAKE SERVICE PROCEDURES

BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

POWER BRAKE UNITS, GENERAL MOTORS -> Delco-Moraine Brake Boosters -> TANDEM DIAPHRAGM TYPE -> Assemble -> BOOSTER SERVICE -> DESCRIPTION -> Disassemble
Vehicle: 1991 GMC K1500 Pickup Sierra XC 5.7 V8 GAS

DESCRIPTION

These units, Figs. and , have a vacuum power chamber that consists of a front and rear shell, a housing divider, front and rear diaphragm and plate assemblies, an hydraulic pushrod and a diaphragm return spring.

The unit operates in much the same manner as the Single Diaphragm unit described above. The diaphragm and plate assemblies use the pressure differential created by engine intake manifold vacuum and atmospheric pressure to assist the hydraulic pushrod.

BOOSTER SERVICE

Disassemble
  • Remove boot, silencer, vacuum check valve, grommet and front housing seal Fig. ...

CLICK HERE TO GET FULL ACCESS TO 1991 GMC K1500 Pickup BRAKE SERVICE PROCEDURES

BRAKE SERVICE PROCEDURES FOR 1991 GMC K1500 Pickup AUTOMOBILES

Includes anti-lock brakes, disc, drum, power and hydraulic brake services diagnostics and procedures for domestic and imported 1991 GMC K1500 Pickup cars and light trucks from 1990+.

ANTI-LOCK BRAKES, GENERAL MOTORS -> Four Wheel Anti-Lock Brake System -> SYSTEM SERVICE -> BLEEDING EHCU MODULE
Vehicle: 1991 GMC K1500 Pickup Sierra 4.3 V6 GAS

BLEEDING EHCU MODULE

The EHCU Module should be bled after replacement or if trapped air is in the unit. If bleeding is required the module must be bled thoroughly before the wheel cylinders and calipers.

There are two bleeders on top of the unit that appear to be normal bleeders, Fig. . These are modulator bleeders and must remain closed when the unit is not pressurized.

The internal bleeders are on either side of EHCU module. The valves are used to open the internal passages within the EHCU module. Both bleed valves must be rotated 1/4-1/2 a turn counterclockwise before beginning t...

CLICK HERE TO GET FULL ACCESS TO 1991 GMC K1500 Pickup BRAKE SERVICE PROCEDURES

Shop online for auto body parts, engines, wheels, lights...

Click here to view more details about 1999 GMC Yukon Fender Flares, Front, Passenger Side1999 GMC Yukon Fender Flares, Front, Passenger Side, A high quality, OE replacement fender trim; Backed by 1-year, unlimited-mileage warranty..

Source: Auto Body Parts Store

$6.06

Click here to view more details1997 GMC K1500 Fuel Pump, A high quality, direct fit OE replacement fuel pump; With 2 years limited Trustbuilt warranty..

Source: Auto Body Parts Store

$77.57

Click here to view more details2012 GMC Canyon Driver Side Head Light Assembly, Driver Side Head Light Assembly; With Black Bezel; Without Extreme Package, , .

Source: Wheels / Rims, Mirrors & Lights Store

$75.50

Click here to view more details1998 GMC K1500 Pickup Sierra XC V8, 5 L, 305 CID Rebuilt Engine, SFI, roller lifters, plastic timing cover, Warranty: 3-Year/100,000 Mile, .

Source: Rebuilt Engines Store

$1,640.00

Click here to view more details1988 GMC K1500 Pickup Used Cooling Fan Assembly, Fan Assm, Very Good.

Source: Used Auto Parts Store

$105.00

Click here to view more details1994 GMC K1500 Pickup Used Fan Clutch, 8-350 (5.7L), ID BT, Very Good.

Source: Used Auto Parts Store

$62.00
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