TM 5-3895-374-24-2
GENERAL
The maintenance section of this book covers only
those operations with which maintenance personnel may
not be too familiar. It is expected that the average
mechanic’s training and experience will permit him to
perform the more common maintenance functions without
the need for detailed instructions.
AIR VALVE INSPECTION
(See Valve/Gasket Kit on Pages 21 & 23)
The valve assemblies should be removed from your
compressor and new valves installed to the valve plate after
every 2000 hours of operation.
1.
Refer
to
the
instructions
furnished
with
the
valve/gasket kit to replace the valves.
2.
Refer to Figure 6-1. Disconnect and remove the
tubing to the inlet unloader(s). Remove the inlet
filter/silencer from the inlet unloader cover.
3.
Loosen and remove the inlet unloader capscrews,
then pull the inlet unloader cover away from the air
head, using care not to damage the inlet cover
o-ring.
4.
Loosen and remove the capscrews securing the
intercooler manifold to the air head.
5.
Loosen and remove the air head capscrews from
the air head, and remove the air head from the
valve assembly. If the valve assembly and the air
head are removed from the cylinder together,
observe the assembly direction of the valve plate
before removing from air head. Make note of this
direction in order to re-assemble the air head and
valve assembly to the cylinder.
6.
Reverse
the
disassembly
procedures
to
re-
assemble the compressor. (See Torque Valve
Table below.)
Figure 6-1. Valve and air head assembly.
TORQUE VALUE TABLE
NATIONAL COARSE
GRADE 2
GRADE 5
GRADE 8
Dia. Pitch
Ft. Lbs.
Kg - Meters
Ft. Lbs.
Kg - Meters
Ft. Lbs.
Kg-Meters
1/4"-20
4
.55
6
.82
9
1.24
5/16"-18
8
1.10
12
1.66
18
2.49
3/8"-16
15
2.10
23
3.18
31
4.29
7/16"-14
24
3.32
36
4.98
51
7.05
1/2"-13
37
5.12
56
7.74
80
11.06
9/16"-12
53
7.33
81
11.20
116
16.04
5/8"-11
68
9.40
113
15.63
160
22.12
3/4"-10
131
18.12
203
28.07
286
39.55
We recommend the use of a torque wrench on all bolts, capscrews, and nuts using the values in the following table. The values given are
for threads lubricated with oil or grease.
To determine the grade of the bolt or capscrew being tightened, use the following information.
Grade 2: No markings or vendor identification on the head.
Grade 5: Letter "S" or 3 lines and/or vendor identification on the head.
Grade 8: Letter "V" or 6 lines and/or vendor identification on the head.
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