5.4 Pump Operation - Model P-84
The model P-84 is equipped with a 4-way, 3-position
control valve. It is designed for use with double-
acting cylinders. See figures 9 and 10.
1. Position lever on 4-way valve to select function as
follows:
(A) Flow directed to port "A"; port "B" returns flow
to the reservoir.
(N) Neutral - ports "A" and "B" open to the reservoir.
(B) Flow directed to port "B"; port "A" returns flow
to the reservoir.
WARNING: Valve contains no load holding
device. Be sure load is supported by
blocking, mechanical stands or other
appropriate supports before moving valve lever to the
neutral (N) position.
A
B
(A)
Figure 9, 4-Way Valve Diagram (P-84)
(B)
Port
"B"
Figure 10, Control Valve Lever Positions
and Hose Connections (P-84)
A
B
A
B
(N)
(B)
(A)
(N)
Port
"A"
air
Figure 11, Air Removal
2. Operate pump to perform work.
3. Change valve positions as needed.
WARNING:
cylinder only when both hoses are
connected to the pump. If one coupler is
left unconnected, high pressure will build behind the
coupler which could cause personal injury and/or
equipment damage.
6.0 AIR REMOVAL
Removing air from the hydraulic system will help the
cylinder to advance and retract smoothly.
6.1 Pump With Single-Acting Cylinder
1. Loosen and remove oil fill plug to provide reservoir
venting during the following steps.
2. Fully close release valve.
3. Position pump in the horizontal position at higher
elevation than cylinder. See Figure 11.
4. Position cylinder with the plunger end down (up if
using pull cylinder).
5. Operate pump to fully extend the cylinder (retract
if using pull cylinder).
6. Open release valve to retract cylinder (extend if
using pull cylinder). This will force the trapped air
to move up to the pump reservoir.
7. Repeat steps 2 through 6 as needed, until cylinder
operation is smooth.
8. Add oil if necessary. See Section 9.1.
9. Reinstall oil fill plug.
6.2 Pump With Double-Acting Cylinder
1. Loosen oil fill plug several turns to allow reservoir
venting during the following steps.
2. Position pump in the horizontal position at higher
elevation than cylinder. See Figure 11.
3. Put cylinder in horizontal position with ports up.
4. Fully advance and retract the cylinder 2 to 3 times.
5. Repeat steps 2 through 4 as needed, until cylinder
operation is smooth.
6. Add oil if necessary. See Section 9.1.
7. Reinstall oil fill plug.
7.0 RELIEF VALVE ADJUSTMENT
1. All models except P-84: Install a 0-15,000 psi
[0-1000 bar] pressure gauge in the pump oil
outlet port. Close the release valve (turn knob fully
clockwise until it stops).
air
Single-acting
Cylinder
6
Operate
double-acting
Double-acting
Cylinder