Maintenance
4-5
HP6A Manual
Hydraulic System:
System Description:
The stroking action of the Rocker Arm is accomplished by applying air pressure to the top and bottom of
the air cylinder, located in the middle of the Rocker arm. To control the speed of the air cylinder there is a
closed hydraulic loop system. The Hydraulic fluid flow is restricted by the stroking speed control valve.
As more or less fluid is allowed to pass through the speed control valve the faster or slower the Rocker
Arm will stroke.
System Check:
With the machine running, watch the Rocker Arm and see if there is any jerking, or bouncing when the
Rocker Arm is changing directions, slow down the stroking speed to 40 SPM. Jerking and bouncing
indicate air in the hydraulic system.
Note:
At very slow stroking speeds, there may be some bouncing of the Rocker Arm at the
bottom of the stroke. This is normal. Increase the stroking speed slightly.
System Refilling and Bleeding:
Locate the Hydraulic Bleeder kit (514-3-30C) that came with the HP6A. It should include the following:
(1) 502-11-17H – 3/8” to ¼” adapter
(2) 514-4-17W – ¼” fitting
(2 ft) 514-4-26 – ¼” air line
(1.5 ft) RX-514-3-30B – Clear Bleeder Tubing
1) Turn the main air off.
2) Remove power from machine.
3) Remove the Plug (7) from the top of the Reservoir (2). Fill the Reservoir (if it is not full) with specified
hydraulic oil. Fill to the mark on the reservoir, do not over fill.
4) Insert one of the ¼” fittings into the 3/8” to ¼” adapter. Insert the ¼” air line into the fitting. Screw
the adapter into the Hydraulic Reservoir where the plug was removed.
5) Screw the other ¼” fitting into an air nozzle.
6) Open the Stroking Speed control valve all the way. (This is the lever on the right hand side of the
carriage. Turn it Horizontal.)
7) Disconnect the Upper Hydraulic Mounting brackets (4) from the Rocker Arm.
8) Push the Hydraulic Cylinder Rod (5) all the way down.
9) Slip the length of Bleeder Hose over the Bleed Valve (6). Run the other end of the hose into a small
container.
10) Open the bleed valve. Apply no more than 15 PSI to the ¼” air line that runs to the top of the
Hydraulic Reservoir. As the air is applied to the reservoir, fluid will come out of the Bleed Valve.
NOTE:
Do not let all of the fluid run out of the Hydraulic Reservoir. This will induce more air into the
Hydraulic System.
11) Close the Bleed Valve and re-fill the reservoir.
12) Repeat the above procedure until there are no air bubbles coming through the bleed Hose.
13) Raise the Hydraulic Cylinder Rod (5) fully.
14) Repeat the filling and draining procedure again until there are no air bubbles coming through the
bleed hose.
15) Reattach the Hydraulic Cylinder Rod to the Rocker arm via the Mounting Brackets.
16) Reapply air and electrical to the machine.
17) Start the machine stroking at 40 SPM, if there is still bouncing or jerking of the Rocker Arm repeat the
bleeding procedure. Not all of the air has been removed from the Hydraulic System.