TM 5-3805-281-24-1
Theory of Operation
1--Left Control Valve--
23--Swing Lift Check Valve
36--Left Propel Neutral
48--Arm Regenerates
5-Spool
24--Power Passage-to-Arm
Passage Lift Check
Valve (in Arm II Spool)
2--Right Control Valve--
I Neutral Passage
Valve
49--Front Pump Control
4-Spool
Check Valve
37--Orifice and Bucket
Valve
3--Rear Pump Control
25--Arm I Lift Check Valve
Power Passage Lift
50--Front Pump Bypass
Valve
26--Restriction Orifice (in
Check Valve
Shut-Off Valve Outlet
4--Flow Combiner Valve
housing)
38--Bucket Dump Circuit
Port
Circuit Check Valve
27--Arm Head End
Relief and
51--Bypass Shut-Off Valve
5--Flow Combiner Valve
Reduced Leakage Pilot
Anti-Cavitation Valve
Pilot Port
6--System Relief Valve
Valve
39--Bucket Flow Control
52--Boom Down Circuit
Isolation Check Valve
28--Arm Head End
Poppet Valve
Relief and
7--System Relief Valve
Reduced Leakage
40--Bucket Flow Control
Anti-Cavitation Valve
Isolation Check Valve
Relief Valve
Pilot Valve B
53--Auxiliary Circuit Relief
8--System Relief and
29--Arm Head End
41--Boom Reduced
and Anti-Cavitation
Power Boost Valve
Reduced Leakage
Leakage Check Valve
Valve
9--Left Propel Valve
Check Valve
42--Boom I Power
54--Rear Pump Control
10--Right Propel Valve
30--Arm Out Circuit Relief
Passage Lift Check
Valve Pilot Inlet Filter
11--Auxiliary Valve
and Anti-Cavitation
Valve
55--Bucket Load Circuit
12--Bucket Valve
Valve
43--Boom Up Circuit Relief
Relief and
13--Boom Reduced
31--Boom II Power
and Anti-Cavitation
Anti-Cavitation Valve
Leakage Pilot Valve
Passage Lift Check
Valve
56--Arm In Circuit Relief
14--Boom Manual Lower
Valve
44--Boom Regenerative
and Anti-Cavitation
Release Screw
32--Auxiliary Power
Valve (in Boom I
Valve
15--Boom II Valve
Passage Lift Check
Spool)
57--Bucket Flow Control
16--Boom I Valve
Valve
45--Orifice and Arm II
Pilot Valve A
17--Arm I Valve
33--Auxiliary Circuit Relief
Power Passage Lift
58--Front Pump Control
18--Arm II Valve
and Anti-Cavitation
Check Valve
Valve Pilot Inlet Filter
19--Bypass Shut-Off Valve
Valve
46--Arm II Neutral Passage
59--Pilot Pressure Signal
20--Swing Valve
34--Front Pump Bypass
Lift Check Valve
Passage Filter
21--Arm Rod End Reduced
Inlet Port
47--Check Valve and
60--Control Valve Circuits
Leakage Pilot Valve
35--Propel Flow Control
Orifice (in Arm II
22--Arm Rod End Reduced
Valve
Spool)
9025
Leakage Check Valve
05
39
CED,TX08227,3117
1904MAY982/2
6-38
