Mitsubishi Montero (1998+). Manual - part 138

completion of the inspection. Magnetic particle inspection applies to

ferrous materials only.

         PENETRANT INSPECTION

         Zyglo

         The Zyglo process coats the material with a fluorescent dye

penetrant. The part is often warmed to expand cracks that will be

penetrated by the dye. When the coated part is subjected to inspection

with a blacklight, a crack will glow brightly.   Developing solution

is often used to enhance results. Parts made of any material, such as

aluminum cylinder heads or plastics, may be tested using this process.

         Dye Check

         Penetrating dye is sprayed on the previously cleaned

component. Dye is left on component for 5-45 minutes, depending upon

material density. Component is then wiped clean and sprayed with a

developing solution. Surface cracks will show up as a bright line.

         ULTRASONIC INSPECTION

         If an expensive part is suspected of internal cracking,

Ultrasonic testing is used. Sound waves are used for component

inspection.

         X-RAY INSPECTION

         This form of inspection is used on highly stressed

components. X-ray inspection maybe used to detect internal and

external flaws in any material.

         PRESSURE TESTING

         Cylinder heads can be tested for cracks using a pressure

tester. Pressure testing is performed by plugging all but one of the

holes in the head and injecting air or water into the open passage.

Leaks are indicated by the appearance of wet or damp areas when using

water. When air is used, it is necessary to spray the head surface

with a soap solution. Bubbles will indicate a leak. Cylinder head may

also be submerged in water heated to specified temperature to check

for cracks created during heat expansion.

         CLEANING PROCEDURES

         * PLEASE READ THIS FIRST *

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         GENERAL

         All components of an engine do not have the same cleaning

requirements. Physical methods include bead blasting and manual

removal. Chemical methods include solvent blast, solvent tank, hot

tank, cold tank and steam cleaning of components.

         BEAD BLASTING

         Manual removal of deposits may be required prior to bead

blasting, followed by some other cleaning method. Carbon, paint and

rust may be removed using bead blasting method. Components must be

free of oil and grease prior to bead blasting. Beads will stick to

grease or oil soaked areas causing area not to be cleaned.

         Use air pressure to remove all trapped residual beads from

components after cleaning. After cleaning internal engine parts made

of aluminum, wash thoroughly with hot soapy water. Component must be

thoroughly cleaned as glass beads will enter engine oil resulting in

bearing damage.

         CHEMICAL CLEANING

         Solvent tank is used for cleaning oily residue from

components. Solvent blasting sprays solvent through a siphon gun using

compressed air.

         The hot tank, using heated caustic solvents, is used for

cleaning ferrous materials only. DO NOT clean aluminum parts such as

cylinder heads, bearings or other soft metals using the hot tank.

After cleaning, flush parts with hot water.

         A non-ferrous part will be ruined and caustic solution will

be diluted if placed in the hot tank. Always use eye protection and

gloves when using the hot tank.

         Use of a cold tank is for cleaning of aluminum cylinder

heads, carburetors and other soft metals. A less caustic and unheated

solution is used. Parts may be lift in the tank for several hours

without damage. After cleaning, flush parts with hot water.

         Steam cleaning, with boiling hot water sprayed at high

pressure, is recommended as the final cleaning process when using

either hot or cold tank cleaning.

         COMPONENT CLEANING

         * PLEASE READ THIS FIRST *

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         SHEET METAL PARTS

         Examples of sheet metal parts are the rocker covers, front

and side covers, oil pan and bellhousing dust cover. Glass bead

blasting or hot tank may be used for cleaning.

         Ensure all mating surfaces are flat. Deformed surfaces should

be straightened. Check all sheet metal parts for cracks and dents.

         INTAKE & EXHAUST MANIFOLDS

         Using  solvent cleaning or bead blasting, clean manifolds for

inspection. If the intake manifold has an exhaust crossover, all

carbon deposits must be removed. Inspect manifolds for cracks, burned

or eroded areas, corrosion and damage to fasteners.

         Exhaust heat and products of combustion cause threads of

fasteners to corrode. Replace studs and bolts as necessary. On "V"

type intake manifolds, the sheet metal oil shield must be removed for

proper cleaning and inspection. Ensure that all manifold parting

surfaces are flat and free of burrs.

         CYLINDER HEAD REPLACEMENT

         * PLEASE READ THIS FIRST *

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         REMOVAL

         Remove intake and exhaust manifolds and valve cover. Cylinder

head and camshaft carrier bolts (if equipped), should be removed only

when the engine is cold. On many aluminum cylinder heads, removal

while hot will cause cylinder head warpage. Mark rocker arm or

overhead cam components for location.

         Remove rocker arm components or overhead cam components.

Components must be installed in original location. Individual design

rocker arms may utilize shafts, ball-type pedestal mounts or no rocker

arms. For all design types, wire components together and identify

according to the corresponding valve. Remove cylinder head bolts.

Note length and location. Some applications require cylinder head

bolts be removed in proper sequence to prevent cylinder head damage.

See Fig. 1. Remove cylinder head.

Fig. 1:  Typical Cylinder Head Tightening or Loosening Sequence

This Graphic For General Information Only

         INSTALLATION

         Ensure all surfaces and head bolts are clean. Check that head

bolt holes of cylinder block are clean and dry to prevent block damage

when bolts are tightened. Clean threads with tap to ensure accurate

bolt torque.

         Install head gasket on cylinder block. Some manufacturer’s

may recommend sealant be applied to head gasket prior to installation.

Note that all holes are aligned. Some gasket applications may be

marked so certain area faces upward. Install cylinder head using care

not to damage head gasket. Ensure cylinder head is fully seated on

cylinder block.

         Some applications require head bolts be coated with sealant

prior to installation. This is done if head bolts are exposed to water

passages. Some applications require head bolts be coated with light

coat of engine oil.

         Install head bolts. Head bolts should be tightened in proper

steps and sequence to specification. See Fig. 1. Install remaining

components. Tighten all bolts to specification. Adjust valves if

required. See VALVE ADJUSTMENT in this article.

NOTE:    Some manufacturers require that head bolts be retightened

         after specified amount of operation. This must be done to

         prevent head gasket failure.

         VALVE ADJUSTMENT

         Engine specifications will indicate valve train clearance and

temperature at which adjustment is to be made on most models. In most

cases, adjustment will be made with a cold engine. In some cases, both

a cold and a hot clearance will be given for maintenance convenience.

         On some models, adjustment is not required. Rocker arms are

tightened to specification and valve lash is automatically set. On

some models with push rod actuated valve train, adjustment is made at

push rod end of rocker arm while other models do not require

adjustment.

         Clearance will be checked between tip of rocker arm and tip

of valve stem in proper sequence using a feeler gauge. Adjustment is

made by rotating adjusting screw until proper clearance is obtained.

Lock nut is then tightened. Engine will be rotated to obtain all valve

adjustments to manufacturer’s specifications.

         Some models require hydraulic lifter to be bled down and

clearance measured. Different length push rods can be used to obtain

proper clearance. Clearance will be checked between tip of rocker arm

and tip of valve stem in proper sequence using a feeler gauge.

         On overhead cam engines designed without rocker arms actuate

valves directly on a cam follower. A hardened, removable disc is

installed between the cam lobe and lifter. Clearance will be checked

between cam heel and adjusting disc in proper sequence using a feeler

gauge. Engine will be rotated to obtain all valve adjustments.

         On overhead cam engines designed with rocker arms, adjustment

is made at push rod end of rocker arm. Ensure that the valve to be

adjusted is riding on the heel of the cam on all engines. Clearance

will be checked between tip of rocker arm and tip of valve stem in

proper sequence using a feeler gauge. Adjustment is made by rotating

adjusting screw until proper clearance is obtained. Lock nut is then

tightened. Engine will be rotated to obtain all valve adjustments to

manufacturer’s specifications.

         CYLINDER HEAD OVERHAUL

         * PLEASE READ THIS FIRST *

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         DISASSEMBLY

         Mark valves for location. Using valve spring compressor,

compress valve springs. Remove valve locks. Carefully release spring

compressor. Remove retainer or rotator, valve spring, spring seat and

valve. See Fig. 2.