Cincinnati 175 CB - Hydraulic Pressures and Cylinders

3. Pilot Pressure
Turn OFF main drive motor. Install a 0-600 PSI gage
in the manifold test port as shown in Figure 37. Start
main drive motor and read pilot pressure. Pilot
pressure is created by an orifice plug (1/4 pipe) in the
manifold and is non-adjustable. Turn OFF main drive
motor and remove gage.
A return line micronic filter (10 micron) is located adjacent
to the hydraulic manifold, Figure 35. The filter cartridge
should be replaced after each 1,000 operating hours, or
when dirt indicator on filter is in the RED zone with main
drive motor running. Failure to replace filter as specified
could lead to erratic operation of the machine due to
sluggish or sticking valve operation.
CHECKING AND SETTING
HYDRAULIC PRESSURES
I PILOT PRESSURE
90 ±10 PSI
This hydraulic system is equipped \'\Tith male quick-
disconnect fittings at the most frequently checked pressure
ports. Pressure gages with female quick disconnects are
furnished with the machine.
1. Main Relief Pressure.
CYLINDERS
Replacing Piston Rod Seal:
1. Run ram to the maximum down position. Block both
ends of the ram.
Adjust the ram parallel to bed. Turn OFF main drive
motor. Install a 0-5000 PSI gage in the relief valve
test port as shown in Figure 37. Restart the main
drive motor and inch the ram upward by manually
actuating solenoid SV1-A until the pistons bottom out
on the upper cylinder heads. Actuate solenoid SVI-A
again and read main -~lief pressure (do not keep SVI-A
actuated for more than 5 seconds at a time). If the
pressure is incorrect, see below, loosen locknut and
turn socket head screw to adjust. Turn the adjusting
screw clockwise to increase or counterclockwise to
decrease the pressure. Retighten locknut after
adjustment is complete. Turn motor OFF and remove
pressure gage.
1~ SQ.
13 3
32 DIA. HOLE FOR 8' x 2
HEX HEAD SCREW
~H---~----'H~--l
FIGURE 38
FIGURE 39
Turn OFF nlachine and LOCK the electrical disconnect.
~ -13 UNC HOLE
FOR
slLONG SQ.
HEAD SCREW
Remove ram pin cover plate on front of ram. Using
extractor bart Figure 38, remove the ram shoe, Figure
39.
2.
3.
200-250 PSI
2500 PSI I
FIGURE 37
MAIN RELIEF
IMAIN .RELIEF PRESSURE
I COUNTERBALANCE PRESSURE
2. Counterbalance Pressure
Turn OFF main drive motor. Install a 0-600 PSI gage
in either counterbalance valve test ports as shown in
Figure 37. Set the machine to run a full length down
stroke in low speed. Restart the main drive motor.
The counterbalance pressure is checked while running
in low speed down stroke (see below). If . the pressure
is incorrect,adjust by loosening locknut and turning
hex head bolt on counterbalance valve. Turn the
adjusting bolt clockwise to increase or counterclockwise
to decrease the pressure. Check and adjust other
counterbalance valve. It is more important to have
both counterbalance valves set to the same pressure
than it is to have the exact pressure setting specified
below. Retighten locknut after adjustment is
completed. Turn motor OFF and remove the pressure
gage.
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