Required tools
You can perform the service procedures described in this manual using common mechanic’s tools.
Special tools, if required are shown. Use calibrated pressure gauges to ensure accuracy. Use snubbers to
protect pressure gauges.
Port locations and gauge installation
The following sections list the ports for each type of hydraulic unit. The fitting size and recommended
pressure gauge are also specified.
The following table and drawings show the port locations and gauge sizes needed.
Port information
Port identifier
Pressure obtained
Gauge size
Port size
M1, M2
System pressure
1000 bar [10 000 psi]
9/16-18
M3 (M6)
Charge pressure
50 bar [1000 psi]
9/16-18
M4, M5
Servo pressure
50 bar [1000 psi]
9/16-18
L1, L2
Case pressure
10 bar [100 psi]
030-042
7/8-14
055-100
1-1/16-12
130
1-5/16-12
180-250
1-5/8-12
X1, X2
HDC/EDC control pressure
50 bar [1000 psi]
7/16-20 or 9/16-18
X3
External control pressure
50 bar [1000 psi]
9/16-18
S
Charge pump inlet
Vacuum gauge,
Tee into inlet line
030-042
1-1/16-12
055-075
1-5/16-12
100-180
1-5/8-12
250
1-1/2 SAE-split flange
Service Manual
Series 90 Pumps
Pressure measurement
22
520L0818 • Rev 0101 • August 2015
