Pressure change
Control option
PC adjustment
LS adjustment
J Frame
LS, LD, LB, LE, PC, RP
42 bar/rev [609 PSI/rev]
17.2 bar/rev [250 PSI/rev]
BB, BC, BP, BS
36 bar/rev [534 PSI/rev]
AB, AC, AD, AJ, AS
8.5 bar/rev [123 PSI/rev]
Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
520L0607
• Rev AI • Sep 2013
21
Adjustments
PC Control
PC setting is indicated in the pump model code. Refer to the
Series 45 J Frame Open Circuit Axial Piston
Pumps Technical Information Manual,
520L0676
, for more information.
Before performing adjustments, read page 15,
Pressure measurement.
1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in case
drain port L1 or L2 to measure case pressure.
C
2. Start the prime mover and allow fluid to reach normal operating temperature. Operate a hydraulic
function to its full extension, loading the pump at maximum pressure and zero flow.
3. Loosen the PC set screw and turn the PC adjusting plug until the desired setting is indicated on the
pressure gauge at port M1¹. Clockwise rotation increases pressure, counterclockwise rotation
decreases; approximate gain 42 bar [610 psi] per turn.
If the pressure does not increase, an external system relief valve may require adjustment. External
system relief valve must be set above the PC setting for proper operation.
4. While holding the position of the PC adjusting plug, torque the PC set screw to 7.5 - 10.8 N•m
[5.5 - 8 lbf•ft].
5. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
configuration.
Warning
Escaping hydraulic fluid under
pressure can have sufficient
force to penetrate your skin
causing serious injury and/or
infection. Relieve pressure in
the system before removing
hoses, fittings, gauges, or
components.
Unintended movement of the
machine or mechanism may
cause injury to the technician
or bystanders. To protect
against unintended
movement, secure the
machine or disable/disconnect
the mechanism while
servicing.
1
P C setting is referenced to case pressure. Subtract case pressure from system pressure to compute the actual setting.
PC control adjustment
PC adjusting plug
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
Case drain port L1
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
Gauge port M1
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
PC set screw
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
P104 365E
Caution
Contamination can damage
internal components and void
the manufacturer’s warranty.
Take precautions to ensure
system cleanliness when
removing and reinstalling
system lines.