Mack E7, Руководство по обслуживанию

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200 BENCH PROCEDURES
Page 5-27
Figure 5-27 — Valve Assembly
[213 EX] Cylinder Head Inspection
Pressure Test — It is recommended that cylinder
heads be pressurized and checked for internal
cracks and leaks. Refer to Cylinder Head and
Cylinder Block Leak Test procedures in the
TROUBLESHOOTING section of this manual.
Check cylinder head deck surface for warping,
pitting or other imperfections. Deck surface
flatness for a new head must not vary more
than 0.0015 inch (0.0381 mm) over 18 inches
(45.7 cm) of surface area. Resurface or replace
as necessary.
When resurfacing, remove a minimum amount
of material from deck to obtain a flat, uniform
surface. Standard head height is 6.397–6.391
inches (162.483–162.310 mm). A maximum
of 0.010 inch (0.254 mm) of material may be
removed, making the minimum height of a
resurfaced head 6.381 inches (162.077 mm).
When the deck is resurfaced, fire ring groove
and valve seat insert dimensions must be
reestablished. Correct dimensions are shown
in this section.
[213 EH] Fire Ring Groove
DESCRIPTION
Fire ring grooves are located in the machined flat
surface of the cylinder head that mates with the
engine block. These grooves correspond with the
fire ring machined lip on cylinder liner. This
design provides a locking groove for the fire ring
to seat as well as a positive-combustion pressure
seal.
After resurfacing the cylinder head deck, it is
necessary to reestablish the fire ring groove
depth using fire ring groove cutter J 29600-C.
Figure 5-28 — Fire Ring Groove Cutter J 29600-C
1. Valve spring keepers
2. Upper washer
3. Valve spring
4. Oil seal
5. Lower washer
(Roto-Coil)
6. Valve
200483a
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2
3
4
5
6
1. Alignment fixture
2. Hold-down capscrews
3. Spacers
4. Washers
5. Cutter head (J 37719)
6. Wing nuts
7. Thickness gauges
8. Cutter base
7
6
5
4
3
2
1
8
200287a
5-101.bk Page 27 Friday, March 17, 2006 11:05 AM