Component Disassembly; Gasket Sealing Surfaces; Hose Removal Tips; Tools - Jeep cherokee 1989 Owner's Manual

for Grade 2 and Grade 3 fasteners. Higher grades can tolerate higher
torque values.
Fasteners laid out In a pattern, such as cylinder head bolts, oil pan
bolts, differential cover bolts, etc., must be loosened or tightened in
sequence t o a v o ~ d warping the component. This sequence will nor-
mally be shown in the appropriate Chapter. If a specific pattern is not
given, the following procedures can be used t o prevent warping.
Initially, the bolts or nuts should be assembled finger-tight only. Next,
they should be t~ghtened one full turn each, In a criss-cross or diagonal
pattern. After each one has been tightened one full turn, return t o the
first one and tighten them all one-half turn, followmg the same pat-
tern. Fmally, tighten each of them one-quarter turn at a time until each
fastener has been tightened t o the proper torque. To loosen and remove
the fasteners, the procedure would be reversed.

Component disassembly

Component disassembly should be done w i t h care and purpose t o
help ensure that the parts go back together properly. Always keep track
o f the sequence in which parts are removed. Make note of special
characteristics or marks on parts that can be installed more than one
way, such as a grooved thrust washer on a shaft. It is a good idea
t o lay the disassembled parts out on a clean surface in the order that
they were removed. It may also be helpful t o make sketches or take
instant photos of components before removal.
When removing fasteners from a component, keep track of their loca-
tions. Sometimes threading a bolt back in a part, or putting the washers
and nut back on a stud, can prevent mix-ups later. If nuts and bolts
cannot b e returned t o their original locations, they should be kept in
a compartmented box or a series of small boxes. A cupcake or muffin
tin is ideal for this purpose, since each cavity can hold the bolts and
nuts from a particular area (i.e. oil pan bolts, valve cover bolts, engine
mount bolts, etc.). A pan of this type is especially helpful when work-
ing on assemblies with very small parts, such as the carburetor, alter-
nator, valve train or interior dash and trim pieces. The cavities can be
marked w i t h paint or tape t o identify the contents.
Whenever wiring looms, harnesses or connectors are separated, it
is a good idea t o identify the t w o halves with numbered pieces of mask-
ing tape so they can be easily reconnected.

Gasket sealing surfaces

Throughout any vehicle, gaskets are used t o seal the mating sur-
faces between t w o parts and keep lubricants, fluids, vacuum or
pressure contained in an assembly.
Many times these gaskets are coated with a liquid or paste-type
gasket sealing compound before assembly. Age, heat and pressure can
sometimes cause the t w o parts t o stick together so tightly that they
are very difficult t o separate. Often, the assembly can be loosened by
striking it w i t h a soft-face hammer near the mating surfaces. A regular
hammer can be used if a block of wood is placed between the hammer
and the part. Do not hammer on cast parts or parts that could be easily
damaged. With any particularly stubborn part, always recheck t o make
sure that every fastener has been removed.
Avoid using a screwdriver or bar t o pry apart an assembly, as they
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Maintenance techniques, tools and working facilities
can easily mar the gasket sealing surfaces of the parts, which must
remain smooth. If prying is absolutely necessary, use an old broom
handle, but keep in mind that extra clean u p will be necessary if the
wood splinters.
After the parts are separated, the old gasket must be carefully
scraped off and the gasket surfaces cleaned. Stubborn gasket material
can be soaked w i t h rust penetrant or treated w i t h a special chemical
t o soften it so it can be easily scraped off. A scraper can be fashioned
from a piece of copper tubing by flattening and sharpening one end.
Copper is recommended because it is usually softer than the surfaces
t o be scraped, which reduces the chance of gouging the part. Some
gaskets can be removed with a wire brush, but regardless of the method
used, the mating surfaces must be left clean and smooth. If for some
reason the gasket surface is gouged, then a gasket sealer thick enough
t o fill scratches will have t o be used during reassembly of the com-
ponents. For most applications, a non-drying (or semi-drying) gasket
sealer should be used.

Hose removal tips

Warning: the vehicle is equipped with air conditioning, do not discon-
nect any of the A/C hoses without first having the system depressurized
by a dealer service department or an air conditioning specialist,
Hose removal precautions closely parallel gasket removal precau-
tions. Avoid scratching or gouging the surface that the hose mates
against or the connection may leak. This is especially true for radiator
hoses. Because o f various chemical reactions, the rubber in hoses can
bond itself t o the metal spigot that the hose fits over. To remove a
hose, first loosen the hose clamps that secure it t o the spigot. Then,
w i t h slip-joint pliers, grab the hose at rhe clamp and rotate it around
the spigot. Work i t back and forth until i t is completely free, then pull
it off. Silicone or other lubricants will ease removal if they can be
applied between the hose and the outside of the spigot. Apply the same
lubricant t o the inside of the hose and the outside o f the spigot t o
simplify installation.
As a last resort (and if the hose is t o be replaced w i t h a n e w one
anyway), the rubber can be slit w i t h a knife and the hose peeled from
the spigot. If this must be done, be careful that the metal connection
is not damaged.
If a hose clamp is broken or damaged, d o not reuse it. Wire-type
clamps usually weaken w i t h age, so it is a good idea t o replace them
w i t h screw-type clamps whenever a hose is removed.

Tools

A selection of good tools is a basic requirement for anyone who plans
t o maintain and repair his or her o w n vehicle. For the owner w h o has
f e w tools, the initial investment might seem high, but when compared
t o the spiraling costs of professional auto maintenance and repair, it
is a wise one.
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