Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET1982SUBURBAN C20, 5.7L ENG VIN M, STANDARD TRANSREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCEFUEL DELIVERYROCHESTER MODELS M4MC & M4ME 4-BARRELOVERHAULDISASSEMBLYAIR HORN
1982 Chevrolet Suburban C20, 5.7L Eng VIN M, Standard Trans
Air Horn
1982 Chevrolet Suburban C20, 5.7L Eng VIN M, Standard TransSECTION Air Horn
- Remove upper choke lever from end of choke shaft by removing retaining screw. Rotate upper choke lever to remove choke rod from slot in lever. Remove choke rod from lower (inner) lever inside float bowl casting. Remove rod by holding lower lever outward with small screwdriver and twisting rod counterclockwise.
- Remove vacuum hose from primary vacuum break unit. Remove secondary metering rods by removing small screw in top of metering rod hanger. Lift upward on metering rod hanger until secondary metering rods are completely out of air horn. Metering rods may be disassembled from hanger by rotating ends out of holes in end of hanger.
- Drive pump lever pivot pin inward until pump lever can be removed. Disconnect pump rod from pump lever. Note location of pump rod for reassembly reference.
- Remove air horn-to-float bowl attaching screws. Countersunk screws (2) are located next to venturi. Remove secondary air baffle deflector (if equipped) from beneath 2 center attaching screws. Remove air horn from float bowl by lifting straight up. Gasket should remain on float bowl for later removal.
- Remove primary vacuum break attaching screws and vacuum break diaphragm. Disconnect diaphragm from air valve rod and remove rod from air valve lever.
- Invert air horn to remove pump plunger stem seal (if used). Using a small screwdriver, remove staking holding seal retainer in position. Remove and discard retainer and seal. Use care removing pump plunger stem seal from air horn to prevent damage to air horn casting.
- It is not necessary to remove choke valve and shaft unless bent or damaged. Choke valve screws are staked in position. Staking must be removed before screws are removed.
- Further disassembly of air horn is not required. Air valve screws are permanently staked in position. However, a repair kit is available for air valve closing spring and center plastic eccentric cam.
RENDER: 1.0x
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.