SENR3977
8 Page, UHE
©
1988 Caterpillar
All Rights Reserved
Printed in U.S.A.
SENR3977
September 1988
446 Backhoe Loader
Hydraulic System
6XF1-UP
SENR3977
8 Page, UHE
NO. DESCRIPTION NO. DESCRIPTION
1 STEERING CYLINDER 31 STICK CONTROL VALVE
2 HAND METERING UNIT 32 BUCKET CYLINDER
3 HMU SIGNAL CHECK VALVE 33 RELIEF VALVE-HEAD END
4 HMU INLET CHECK VALVE 34 RELIEF VALVE-ROD END
5 STEERING ACCUMULATOR 35 BUCKET CONTROL VAL VE
6 SUPPLEMENTAL STEERING VALVE 36 BOOM CYLINDER
7 TILT CYLINDER 37 RELIEF VALVE-ROD END
8 RELIEF VALVE-HEAD END 38 RELIEF VALVE-HEAD END
9 RELIEF VALVE-ROD END 39 RH SWING CYLINDER
10 TILT CONTROL VALVE 40 ORIFICE CHECK VALVES
11 MAKEUP VALVE 41 BOOM CONTROL VALVE
12 LIFT CYLINDERS 42 RELIEF VALVE
13 LIFT CONTROL VALVE 43 LH SWING CYLINDER
14 RELIEF V ALVE-AUXILLARY CYLINDER 44 RELIEF VALVE
15
SUPPLEMENTAL STEERING STATUS SWITCH
45 INLET MANIFOLD
16 AUXILLARY CONTROL VALVE 46 SWING CONTROL VALVE
17 STEERING PRIORITY VALVE 47 AUXILLARY CONTROL VALVE
18 BRAKE ACCUMULATOR 48 RH STABILIZER CYLINDER
19
ACCUMULATOR CHARGING VALVE
49 ORIFICE CHECK VALVE
20 BRAKE ACCUMULATOR STATUR SWITCH 50 STABILIZER LOCK VALVE
21 BRAKE VALVE 51 ORIFICE CHECK VALVE
22
CASE DRAIN FILTER
52 RH STABILIZER CONTROL VALVE
23 BREAKER RELIEF VALVE 53 STABILIZER LOCK VALVE
24
HYDRAULIC TANK
54 ORIFICE CHECK VALVE
25 RETURN OIL FILTER 55 ORIFICE CHECK VALVE
26 HYDRAULIC PUMP GROUP 56 LH STABILIZER CYLINDER
27 OIL COOLER 57 LH STABILIZER CONTROL VALVE
28
STICK CYLINDER
58 EXTENDIBLE STICK CYLINDER
29 RELIEF VALVE-HEAD END 59 EXTENDIBLE STICK CONTROL VALVE
30 RELIEF VALVE-ROD END 60 INLET MANIFOLD
446 BACKHOE LOADER HYDRAULIC SYSTEM SCHEMATIC
TEST POINT PRESSURE TAP
A PUMP PRESSURE
B SIGNAL PRESSURE
