SEALS, GASKETS & SEALANTS

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SEALS, GASKETS & SEALANTS
Installing
Seals
and Gaskets
OBJECTIVES
Identify common gaskets and seals
 Properly install common engine gaskets
including cylinder head & valve cover
gaskets.
 Properly install typical lip seals.
 Properly use silicone Sealers and
adhesives when installing engine parts.

PURPOSE OF A GASKET

Purpose of a Gasket
– To confine; gas, oil, water, vacuum or exhaust
– Seal out foreign objects such as; Dirt, Water
– Must withstand heat, cold, pressure, erosion,
corrosion, moisture and oil
GASKET MATERIALS

Gasket Materials
– synthetic rubber
– cork-rubber
– embossed steel (Corrugated)
– paper
GASKET MATERIALS
cork-rubber
synthetic rubber/Neoprene
GASKET MATERIALS
embossed steel (Corrugated)
paper
WHAT CAUSES LEAKS

Causes of leakage,
– Worn or damaged seals
– Worn or damaged gaskets
– Worn or bent parts or shafts
– Fasteners over tighten or to loose
– wrong parts or gaskets
– nicks or burrs
– Improper installation
Gasket Replacement
When Replacing gaskets ask yourself ,
"Why did this gasket fail"
 List different things to look for.
 Did the gasket fail suddenly or over a period
of time?
 Check the Torque

– is it to Tight
– is it to Loose
Check for warp is the valve cover bent
or the bolt holes pulled through
 Do both surfaces match up
 Examine the gasket very close, are the
holes in the same spot

Gasket Replacement
Gasket Replacement
If you just replace the gasket it may go
out again.
Also some Bolts need to be checked
for torque for example some head
gaskets need to be retorqued.
When using installing gaskets check
the manufactures instructions for the
proper procedures.
GASKET INSTALLATION

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Follow instructions.
Thoroughly clean & dry the mating surface.
Match to old gasket.
Check for proper fit. Is it the right shape, do the
bolt holes all line up.
Never reuse gaskets.
Ask yourself, Do you need Sealer. Use high tack
or 3M Weather stripping to hold in place. Only
use Silicone on mating lines and where two
gasket are joined together, like on valve covers.
GASKET INSTALLATION
Note
where
sealer is
to be
applied.
 Thanks to
Alldata for
picture

GASKET INSTALLATION
Use alcohol or brake clean on a clean rag
to wipe the oil off of the gasket surface
 Is the surface dry
 Tighten in steps
 Use the torque pattern when tightening
 Torque to proper specs
 Use a quality gasket, saving a buck or
two on a cheap gasket or trying to reuse
a gasket is not worth it.

CYLINDER HEAD GASKET

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When tightening a cylinder head gasket that is
not torque to Yield it is best to tighten in steps.
How much should you go, my rule of thumb
has been if under 60 lbs. Tighten in 2 steps.
If over 60 lbs. tighten in three steps. For
example if it is to be tighten to 100 foot lbs.
Tighten in this sequence 35 – 70 – 100.
Many other bolts are to be tighten in steps
check the specifications for the car.
CYLINDER HEAD GASKET

Must be capable of withstanding tremendous
heat and pressure.
CYLINDER HEAD GASKET

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Follow gasket makers instructions on whether
or not to use a sealant. Most want you to just
clean and dry the surface.
What type of sealant and how much? Most
head gaskets do not want any sealant. If you
have an aluminum head and a cast iron block
(sometimes referred to as a bi-metal engine) it
will expand at different rates, if you use a
sealant you are going to have a leak. Most
manufactures will use a graphite gasket to
allow for motion during the expansion.
CYLINDER HEAD GASKET

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Run a tap or thread chaser in bolt holes.
Multi-layer steel gasket
CYLINDER HEAD GASKET

Always tighten the bolts in the correct
sequence look at the pattern.
CYLINDER HEAD GASKET
Look at the pattern, starts in the center and
rotates out.
CYLINDER HEAD GASKET
USING STRAIGHTEDGE
Check in several directions what is the specifications?
How much can be taken off?
Torque to Yield Bolts
Torque to yield (TTY) bolts are used in
many engines today, the bolts need to be
replaced. When installing them you need
to have them clean and oiled then tighten
to manufacture’s preload setting. Then
tightened them in a series of stages
usually about 90 degree’s at a time.
Torque to Yield Bolts
Never reuse a torque to yield bolt. They
are beyond their elastic range, past their
yield point and will break.
 A example would be for a Torque to
yield (TTY) bolt when installing them
you would torque them down to 35 foot
pounds then tighten an additional 70
degrees.
 Every car is different check the manual.

Degree wheel
If your not
familiar with a
degree, Learn
the angles on it.
Where do
gaskets go?
VALVE COVER GASKETS
Check cover flanges for straightness.
 Use load spreaders when available.

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Do not use a sealant. Use high tack or
3M Weather stripping to hold in place.
VALVE COVER GASKETS
Some times referred to as a camshaft cover
VALVE COVER GASKETS
INTAKE MANIFOLD
GASKETS
Steel
Paper
EXHAUST GASKETS
Ring
fiber facing material on one side
and perforated steel on the other.
Fiber surface against the head,
Steel on the manifold.
Doughnut
Exhaust Rings called
Exhaust Doughnuts
OIL PAN GASKETS
Rear main seal
Molded gaskets, oil pan and intake manifold
Rope rear main seal
Rear main seal
VALVE STEM SEALS

Deflector seals usually called umbrella seals
that move with the valve and Positive Seals
attach to the valve boss and GM O-rings
VALVE STEM SEALS
umbrella seals
Deflect the oil
valve
VALVE STEM SEALS

Positive Seals attach to the valve guide.
SEALS

We have come along way from the old felt & leather seal.
Most seals today are made of Nitrile. Some Seals are made of
Viton, Silicone, or Polyacrylics. For more information on
what seals are made of go to the CR website to find out.

The first job of the seal is to keep the oil in and the dirt out
but it can also be used to separate fluids and to with stand
different pressures. Proper installation and inspection is very
important
SEALS
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1.
2.
3.
4.
Seals can be
Spring-loaded
Springless
Single-lip
Multi-lip
SEALS
SKF New web site
SEALS

A. The flexible material component of the seal which produces the
lip. In this design there is only one lip, the primary sealing lip.
B. The outer shell of the seal holds the seal in place.
C. The garter spring (found in most seal designs) is a coiled wire
spring that provides a controlled radial load over time.
SEAL INSTALLATION
Inspect the shaft that the seal rides on
it might be bent or damaged. You
may have to install a sleeve or clean
up with crocus cloth or replace with a
new part
SEAL INSTALLATION
Install with lip (and garter spring) toward
liquid.
 Lubricate lip before installation.
 Use sealant on the outside of steel seals.
 Use a seal installer.

Check out the power point on seals
and seal failures
Speedi-Sleeve shaft repair

Clean and measure the diameter of the
worn shaft
Speedi-Sleeve shaft repair

Place the sleeve on the shaft then put
on the installation tool
Speedi-Sleeve shaft repair

Hammer or press the sleeve onto the
shaft far enough to cover the worn area
USING SEALANTS
Use proper sealant for application.
 Do not use a sealant unless specified in
service manual or by gasket manufacturer.
 Types of sealants

– Hard drying like 3M Weather stripping or a
glue to keep a gasket in place
– Aerobic (RTV)cures when exposed to air
– Anaerobic cure after the components are put
together (Thread lockers)
Aerobic (RTV)
RTV - Room Temperature Vulcanizing
 called Silicone Sealant
 Replaces most gaskets
 forms a rubber seal by absorbing moisture
in the air
 Sets in about ten minutes Dries in about 2
hours fully cures in 24 hours.
 Cure times will vary with Temperature,
Humidity, and size of the gap

Aerobic (RTV)
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Blue is the most common color but also
comes in Black, gray, bronze,clear, red
and white(white is for the bathroom)
Aerobic (RTV)
Make sure that it is O2 Sensor safe if
used around the engine
 Do not use around Gasoline
 Clean and dry surface before using
 When using around bolt holes go all the
way around the hole.
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Thread lockers
 Anaerobic
cures after the
components are put together
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Locks Bolts & Studs against Vibration
loosening
Clean and dry all parts removing dirt, oil,
grease and/or any foreign material
Thread lockers
 Four
colors
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Use on screws up to ¼ - Purple
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# 242 Able to Remove up to 3/4" Bolts - Blue
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# 271 High Strength Hard to Remove up to 1" Dia. - Red
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# 290 Wicking Grade for Preassembled Parts - Green
 # could be different due to size of bottle
Purple Thread lockers
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Low strength
Use on screws up to ¼
Applied BEFORE Assembly
Carburetors, relay locks,
headlamps, throttle body
assembly, choke
assembly and fuel
injection set screws, body
panel mounting fasteners
Blue Thread lockers

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Medium Strength for all bolts ¼ or
larger
Able to Remove with hand tools
Prevents parts from loosening from
vibration
Protects threads from corrosion
Recommend for valve cover
bolts,rocker arm nuts, carburetor
studs, motorcycle, jet skis
snowmobiles etc.
Applied BEFORE Assembly
Red Thread lockers
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High Strength Hard to Remove
Works well for studs and press
fit
Locks against heavy vibration
Requires extra effort to remove
or special tools like heat
OEM specified as 271
Applied BEFORE
Assembly
Green Thread lockers
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Wicking Grade for
Pre-assembled Parts
Use on Calibration and
adjustment screws
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Applied AFTER Assembly
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OEM specified as 290
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There is also a Green High
Strength for sleeves
Thread / Pipe Sealant
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Liquid Teflon
Thread Sealant for metal
tapered pipe threads and
fittings, replaces teflon tape
Suggested applications
Stainless steel fittings, head
bolts into through holes (water
Jacket), oil PSI sending
units/sensors, oil and coolant
lines, intake manifold switches,
rear axle fill plug, fuel fittings
Teflon Tape

Prevents leaks Just wrap tape around
threads on pipes that carry air or liquid

Use on stainless,
aluminum, plastic, iron,
copper, or brass.
O-Rings

O-rings come in several sizes the most
common standard sizes are
1/16, 3/32, 1/8, 3/16, 1/4
O-Rings
O-Rings come in several shapes an O
being the most common but you can
find others in D shape, Square-ring and
a modified X.
 O-Rings also come in different types of
materials. Make sure what you are
using is compatible with the fluid it is
next to.
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O-Rings material types
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For this little leak
A
L Thanks to Federal Mogul for some of the pictures and
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