Danfoss Series 42 Service Manual

Required tools
You can perform the service procedures in this manual using common mechanic’s hand-tools. Calibrate
gauges frequently to ensure accuracy. Use snubbers to protect pressure gauges.
Port locations and pressure gauge installation
A pump with a manual displacement control (MDC) and no filtration adapter is shown. With non-
feedback controls, the positions of the case drains may vary. With a filtration adapter, the porting in the
filtration options area varies.
Ports and pressure gauges
Proper service and diagnosis may require pressure measurement at various points in the hydraulic circuit.
The Series 42 pump has several locations at which to take these measurements. The following illustration
shows the locations of the various gauge ports. The table shows the recommended gauge size and the
fitting size for each port. Refer to this information when installing pressure gauges.
Gauge ports
Gauge
port
Pressure measured Recommended gauge
size
O-ring boss
28/32 cc 41 / 51 cc
M1 & M2 System pressure for ports A and B 600 bar [8700 psi] 9/16/-18 9/16/-18
M3 Charge pressure 60 bar [870 psi] 3/4-16 * 3/4-16 *
M4 & M5 Servo pressure 60 bar [870 psi] 9/16-18 9/16-18
L1 & L2 Case pressure 35 bar [510 psi] 1-1/16-12 1-5/16-12
S Charge pump inlet pressure 1 bar [30 in Hg vacuum] 1-1/16-12 1-5/16-12
* Some older models may use a 9/16-18 O-ring fitting.
28/32 cm
3
base unit with MDC and no filtration adapter
Servo pressure
gauge port M5
Case Drain
Port L2
Charge pressure
gauge port M3
(charge pressure
supply for no
charge pump
option)
Charge pump
inlet port S
Servo pressure
gauge port M4
Case drain
port L1
System pressure
gauge port M2
System
pressure
port B
System
pressure
port A
System pressure
gauge port M1
RIGHT SIDE VIEW
LEFT SIDE VIEW
P108 067E
Service Manual
Series 42 Axial Piston Closed Circuit Pumps
Pressure Measurement
520L0638 • Rev 0300 • July 2015 23

Danfoss Series 42 Specifications

General

Brand	Danfoss
Model	Series 42
Category	Water Pump
Language	English