Seals and Gaskets

8/12/2019 Seals and Gaskets

1/53

SEALS, GASKETS & SEALANTS

P

H

S

A

U

T

O

SA

L

S

InstallingSeals

and Gaskets


2/53

OBJECTIVES

Identify common gaskets and seals

Properly install common engine gaskets

including cylinder head & valve cover

gaskets.

Properly install typical lip seals.


3/53

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


4/53

GASKET MATERIALS

Gasket Materials synthetic rubber

cork-rubber

embossed steel (Corrugated) paper


5/53

GASKET MATERIALS

cork-rubber

synthetic rubber


6/53

GASKET MATERIALS

embossed steel (Corrugated)

paper


7/53

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


8/53

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

Gasket Replacement


9/53

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


10/53

If you just replace the gasket it may goout again. Clean off all of the old

gasket. Clean and dry the parts, Use

sealer if needed. Tighten in steps

Also some Bolts need to be checked

for torque for example some head

gaskets need to be retorqued when

using some gaskets check the

manufactures instructions.

Gasket Replacement


11/53

Torque to yield (TTY) bolts are used inmany engines today, they need to be

replaced. When installing them you need

to have them clean and oiled then tightento manufactures preload setting. Then

tightened them in a series of stages

usually about 90 degrees at a time.

Also never retorque a torque to yield bolt.

They are beyond their elastic range, past

their yield point and will break.

Torque to Yield Bolts


12/53

A example would be for a Torque to yield

(TTY) bolt when installing them you would

torque them down to 35 foot pounds thentighten an additional 70 degrees.

Torque to Yield Bolts


13/53

GASKET INSTALLATION

Follow instructions.

Thoroughly clean the mating surface.

Match to old gasket.

Check for proper fit. Right shape, bolt

holes all line up

Never reuse gaskets.

Ask yourself, Do you need Sealer


14/53

GASKET INSTALLATION

Use alcohol or brake clean on a clean ragto 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 is not worth it.


15/53

CYLINDER HEAD GASKET

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.

Take it to 35 - 70100.

Many other bolts are to be tighten in steps

check the specs for the car.


16/53


Must be capable of withstanding tremendous

heat and pressure.


17/53


Follow gasket makers instructions on whether

or not to use sealant.

What type of sealant and how much? Most

head gaskets do not want any sealant. If youhave an aluminum head and a cast iron block

it will expand at different rates, if you use a

sealant you are going to have a leak.


18/53


Run a tap or thread chaser in bolt holes.

Multi-layer steel gasket


19/53


Always tighten the bolts in the correct

sequence look at the pattern.


20/53


Look at the pattern, starts in the center and

rotates out.


21/53

USING STRAIGHTEDGE

Check in several directions what is the specifications?

How much can be taken off?


22/53

VALVE COVER GASKETS

Check cover flanges for straightness.

Use load spreaders when available.

Use a sealant only when necessary and

not to much.


23/53

VALVE COVER GASKETS


24/53

INTAKE MANIFOLD

GASKETS

Steel

Paper


25/53

EXHAUST GASKETS

Exhaust Rings called

Exhaust Doughnutsfiber facing material on one sideand perforated steel on the other.Fiber surface against the head,

Steel on the manifold.


26/53

OIL PAN GASKETS

Rear main seal Molded gaskets oil pan and intake manifold


27/53

VALVE STEM SEALS

Deflector seals usually called umbrella sealsthat move with the valve and Positive Sealsattach to the valve boss and GM O-rings


28/53

VALVE STEM SEALS

umbrella seals

Deflect the oil

valve


29/53

VALVE STEM SEALS

Positive Seals attach to the valve guide.


30/53

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 outbut it can also be used to separate fluids and to with stand

different pressures. Proper installation and inspection is very

important
http://www.chicago-rawhide.com/industry/seals/sealfun2.htm


31/53

SEALS

Seals can be

1. Spring-loaded

2. Springless3. Single-lip

4. Multi-lip


32/53

SEALS

SKF New web site
http://www.skf.com/portal/skf/home/products?newlink=firsthttp://www.skf.com/portal/skf/home/products?newlink=firsthttp://www.chicago-rawhide.com/industry/seals/sealfun2.htm


33/53

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.


34/53

Inspect the shaft that the seal rides on

it might be bent or damaged. Youmay have to install a sleeve or clean

up with crocus cloth or replace with a

new part

SEAL INSTALLATION


35/53

SEAL INSTALLATION

Install with lip (and garter spring) towardliquid.

Lubricate lip before installation.

Use sealant on the outside of steel seals. Use a seal installer.


36/53

Check out the power point on seals

and seal failures


37/53

Speedi-Sleeve shaft repair

Clean and measure the diameter of the

worn shaft
http://chicago-rawhide.com/auto/speedi/speedi.htm


38/53


Place the sleeve on the shaft then put

on the installation tool
http://chicago-rawhide.com/auto/speedi/speedi.htm


39/53


Hammer or press the sleeve onto the

shaft far enough to cover the worn area
http://chicago-rawhide.com/auto/speedi/speedi.htmhttp://chicago-rawhide.com/auto/speedi/speedi.htm


40/53

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 Weatherstripping 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)


41/53

Aerobic (RTV) RTV - Room Temperature Vulcanizing

called Silicone Sealant

Replaces most gaskets

forms a rubber seal by absorbing moisturein 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


42/53

Aerobic (RTV) Blueis the most common color but also

comes in Black, gray, bronze,clear, redand white(white is for the bathroom)


43/53

Aerobic (RTV)

Make sure that it is O2 Sensor safe ifused 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.


44/53

Thread lockers

Anaerobic cures after the componentsare put together

Use on screws up to Purple

# 242 Able to Remove up to 3/4" Bolts Blue

# 271 High Strength Hard to Remove up to 1" Dia. Red

# 290 Wicking Grade for Preassembled Parts Green

# could be different due to size of bottle


45/53

Purple Thread lockers

Low strength

Use on screws up to

Applied BEFORE Assembly

Carburetors, relay locks,headlamps, throttle bodyassembly, chokeassembly and fuelinjection set screws, bodypanel mounting fasteners


46/53

Blue Thread lockers Medium Strength for all bolts 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


47/53

Red Thread lockers High Strength Hard to Remove

Works well for studs and press

fit

Locks against heavy vibration

Requires extra effort to removeor special tools like heat

OEM specified as 271

Applied BEFOREAssembly


48/53

Green Thread lockers

Wicking Grade forPre-assembled Parts

Use on Calibration and

adjustment screws Applied AFTER Assembly

OEM specified as 290

There is also a Green HighStrength for sleeves


49/53

Thread / Pipe Sealant

Thread Sealant for metaltapered pipe threads andfittings replaces teflon tape

Suggested applications Stainless steel fittings, head

bolts into through holes (waterJacket), oil PSI sending

units/sensors, oil and coolantlines, intake manifold switches,rear axle fill plug, fuel fittings


50/53

Teflon Tape Prevents leaks Just wrap

tape around threads

Use on stainless,

aluminum, plastic, iron,copper, or brass.


51/53

O-Rings O-rings come in several sizes the most

common standard sizes are

1/16, 3/32, 1/8, 3/16, 1/4


52/53

O-Rings

O-Rings come in several shapes an O

being the most common but you can

find others in D shape, Square-ring anda modified X.

O-Rings also come in different types of

materials make sure what you are usingis compatible with the fluid it is next to.

P


53/53

The End

For this little leak

P

H

S

A

U

TO

SA

LThanks to Federal Mogulfor some of the picturesand
http://www.federal-mogul.com/http://www.chicago-rawhide.com/industry/seals/sealfun2.htmhttp://www.federal-mogul.com/

Seals and Gaskets

Documents