GMC C Series 1993, Руководство по ремонту

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1. Use J 8087 or equivalent (figure 22).
2. Set the gage so the thrust pin must be forced in
about 7 mm (1/4 inch) to enter the gage in the
cylinder bore.
3. Center the gage in the cylinder and turn the dial
to “O ’’ '
4. Carefully work the gage up and down the cylin­
der to determine taper and turn it to different
points around the cylinder wall to determine the
out-of-round condition. ; ’ !
5. If the cylinders are found to exceed the speci­
fied figure for out-of-round or taper, honing or
»■’ boring will be necessary.
6. If the cylinders were found to have less than
0.005 inch taper or wear, they can be condh
tioned with a hone and fitted with the high limit
standard size piston. A cylinder bore of less
than 0.005 inch wear or taper may not entirely
clean up when fitted to a high limit piston. If it is
desired to entirely clean up the bore in these
cases, it will be necessary to rebore for an
oversize piston. If more then 0.005 inch taper or
wear, they should be bored and honed to the
smallest oversize that will permit complete
resurfacing of all cylinders.
7. If honing is not required, the cylinder bore
should be cleaned with a hot water and deter­
gent wash. After cleaning, the cylinder bores
should be swabbed several times with light
engine oil using a clean cloth and then wiped
with a clean dry cloth.
B O R I N G
1. Before using any1 type boring bar, the top of the
cylinder block should be filed to remove any dirt or
burrs. This is very important, if not checked, the
boring bar may be tilted which would result in the
rebdred cylinder wall not being at right angles to
: the crankshaft. ,
2. The piston to be fitted should be measured with a
micrometer, measuring at the center of the piston
skirt and at right angles to the piston pin. The cylin­
der should be bored to the same diameter as the,
piston and honed to give, the specified clearance. ■
3. The instructions furnished by the manufacturer of
the equipment being used should be Carefully fol­
lowed.
H O N I N G ■
1. When the cylinders need honing,, follow' the hbnp
manufacturer’s recommendations for the use of the
hone and cleaning and lubrication during honing.
Use only clean, sharp, stones of the proper grade
for amount of material to be removed. Dull, dirty,
stones cut unevenly and generate excessive heat.
2. Occasionally during the honing operation, the cylin­
der bore should be.thoroughly cleaned and the pis-,
ton selected for the individual cylinder checked fbr
correct fit. v /
N O T IC E : H a n d le th e p is to n s w ith c a re a n d d o
n o t a tte h ip t to fo rc e th e m th ro u g h th e c y lin ­
d e r u n til th e c y lin d e r h a s b e e n h o n e d to c o r­
r e c t s iz e a s t h e p i s t o n c a n b e d i s t o r t e d
th ro u g h c a re le s s h a n d lin g .
3. When finish honing a cylinder bore to fit a piston,
the hone should be moved up and down at a suffi­
cient speed to obtain very fine uniform surface fin­
ish marks in a cross-hatch pattern of about 45
dbgree to 65 degree included angle. The finish
marks should be clean but not sharp, free from
imbedded particles arid torn or folded metal.
4.
Permanently mark the piston tor the cylinder to
which it has been fitted.
5. Clean the bores with hot water and detergent.
Scrub with a stiff bristle brush and rinse thoroughly
with hot water. It is essential that a good cleaning
operation be performed. If any of the abrasive
material is allowed to remain in the cylinder bores,
it will wear the new rings and cylinder bores in
addition to the bearings lubricated by the contami­
nated oil. The bores should be swabbed and then
wiped with a clean dry cloth. Cylinders should not
be cleaned with kerosene or gasoline. Clean the
repiainder of the cylinder block to remove the
excess material spread during the honing opera­
tion.
PISTON AND CONNECTING
n d b ASSEMBLIES
D I S A S S E M B L Y
E R e m o v e o r D i s c o n n e c t ( F i g u r e s 2 3 a n d 2 4 )
Tools Required:
, J 24086-B Piston Pin Remover and Installer Set
1. Piston rings. In most cases the rings should be
discarded arid replaced with new ones at assem­
bly. If the rings are to be reused, however, they
should be installed on the same piston from which
they were removed.
Figure 23— Replacing the Piston Rings
r
• Cylinder out-of-round and taper as follows:
6A2-14 V8 ENGINES, GASOLINE