Chevrolet Silverado / GMC Sierra. Service manual — part 219

Valve lifters, valve rocker arms, and valve rocker arm supports

Valve to the valve guide

Valve spring to cylinder head location

Engine block bearing cap location and direction

Oil pump drive and driven gears

REPLACING ENGINE GASKETS

Gasket Reuse and Applying Sealant

Do not reuse any gasket unless specified.

Gaskets that can be reused will be identified in the service procedure.

Do not apply sealant to any gasket or sealing surface unless specified in the service
procedure.

Separating Components

Use a rubber mallet in order to separate the components.

Bump the part sideways in order to loosen the components.

Bumping of the component should be done at bends or reinforced areas of the component to
prevent distortion of the components.

Cleaning Gasket Surfaces

Use care to avoid gouging or scraping the sealing surfaces.

Use a plastic or wood scraper in order to remove all the sealant from the components.

Do not use any other method or technique to remove the sealant or the gasket material from
a part.

Do not use abrasive pads, sand paper, or power tools to clean the gasket surfaces.

These methods of cleaning can cause damage to the component sealing surfaces.

Abrasive pads also produce a fine grit that the oil filter cannot remove from the engine
oil.

This fine grit is an abrasive and can cause internal engine damage.

Assembling Components

Assemble components using only the sealant (or equivalent) that is specified in the service

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

procedure.

Sealing surfaces must be clean and free of debris or oil.

Specific components such as crankshaft oil seals or valve stem oil seals may require
lubrication during assembly.

Components requiring lubrication will be identified in the service procedure.

Apply only the amount of sealant specified in the service procedure to a component.

Do not allow the sealant to enter into any blind threaded holes, as the sealant may prevent
the fastener from clamping properly or cause component damage when tightened.

Tighten the fasteners to the proper specifications.

USE OF ROOM TEMPERATURE VULCANIZING (RTV) AND ANAEROBIC SEALANT

Sealant Types

The following 2 major types of sealant are commonly used in engines:

Anaerobic sealant room temperature vulcanizing (RTV)

Anaerobic sealant, which include the following:

Gasket eliminator

Pipe

Threadlock

Anaerobic Type Room Temperature Vulcanizing (RTV) Sealant

Anaerobic type room temperature vulcanizing (RTV) sealant cures in the absence of air. This
type of sealant is used where 2 components, such as the intake manifold and the engine block, are
assembled together.

Use the following information when using RTV sealant:

IMPORTANT: Do not overtighten the fasteners.

IMPORTANT: The correct sealant and amount of sealant must be used in the

proper location to prevent oil leaks, coolant leaks, or the
loosening of the fasteners. DO NOT interchange the sealants. Use
only the sealant, or equivalent, as specified in the service
procedure.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

Do not use RTV sealant in areas where extreme temperatures are expected. These areas
include:

The exhaust manifold

The head gasket

Any other surfaces where a different type of sealant is specified in the service
procedure

Always follow all the safety recommendations and the directions that are on the RTV
sealant container.

Use a plastic or wood scraper in order to remove all the RTV sealant from the components.

The surfaces to be sealed must be clean and dry.

Use a RTV sealant bead size as specified in the service procedure.

Apply the RTV sealant bead to the inside of any bolt holes areas.

Assemble the components while the RTV sealant is still wet to the touch, within 3 minutes.

Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Anaerobic Type Gasket Eliminator Sealant

Anaerobic type gasket eliminator sealant cures in the absence of air. This type of sealant is used
where 2 rigid parts, such as castings, are assembled together. When 2 rigid parts are disassembled

NOTE:

Do not allow the RTV sealant to enter any blind threaded hole.
RTV sealant that is allowed to enter a blind threaded hole can
cause hydraulic lock of the fastener when the fastener is
tightened. Hydraulic lock of a fastener can lead to damage to
the fastener and/or the components. Hydraulic lock of a
fastener can also prevent the proper clamping loads to be
obtained when the fastener is tightened. Improper clamping
loads can prevent proper sealing of the components allowing
leakage to occur. Preventing proper fastener tightening can
allow the components to loosen or separate leading to
extensive engine damage.

IMPORTANT: Do not wait for the RTV sealant to skin over.

IMPORTANT: Do not overtighten the fasteners.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

and no sealant or gasket is readily noticeable, then the 2 parts were probably assembled using an
anaerobic type gasket eliminator sealant.

Use the following information when using gasket eliminator sealant:

Always follow all the safety recommendations and directions that are on the gasket
eliminator sealant container.

Apply a continuous bead of gasket eliminator sealant to one flange.

The surfaces to be sealed must be clean and dry.

Anaerobic Type Threadlock Sealant

Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for
threadlocking and sealing of bolts, fittings, nuts, and studs. This type of sealant cures only when
confined between 2 close fitting metal surfaces.

Use the following information when using threadlock sealant:

Always follow all safety recommendations and directions that are on the threadlock sealant

NOTE:

Do not allow the sealant to enter a blind hole. The sealant may
prevent the fastener from achieving proper clamp load, cause
component damage when the fastener is tightened, or lead to
component failure.

IMPORTANT:

Gasket eliminator sealed joint fasteners that are partially
torqued and the gasket eliminator sealant allowed to cure
more than 5 minutes, may result in incorrect shimming and
sealing of the joint.

Do not overtighten the fasteners.

Apply the gasket eliminator sealant evenly to get a
uniform thickness of the gasket eliminator sealant on
the sealing surface.

Tighten the fasteners in sequence, if specified, and to
the proper torque specifications.

After properly tightening the fasteners, remove the
excess gasket eliminator sealant from the outside of the
joint.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado