Maintenance - Greenlee 7904SB QUICK DRAW 90 Handbuch

Maintenance

Maintenance and repairs should be performed in a dust
free area by qualified technicians.
This unit requires minimum maintenance because it
has a closed hydraulic system and all internal parts
are lubricated by the hydraulic fluid. Lubricate lever pins
lightly. Keep contaminants away from ram and cylinder.
Store with handle down and hydraulic pressure released.
Adding Hydraulic Oil
1. Place driver in vise in vertical position with handles
up. Unscrew reservoir handle (21) and remove
bladder plug (20). Open release valve knob (27) to
assure the ram is fully extended.
2. Fill bladder (29) to point of overflow with Greenlee
hydraulic oil.
3. Purge air from system:
Pump handle (22) several times to remove air from
the pumping chamber. Close release valve knob
and pump handle until ram (3) completes its full
travel. Repeat as necessary.
Note: Open release valve knob slowly so ram
extends slowly. Rapid return of oil and
air may cause oil to overflow the rubber
bladder.
If this procedure fails to remove air, remove bladder
plug and open release valve knob. Place thumb
over plug hole in bladder and squeeze bladder while
pumping handle several times. Close the release
valve knob and pump the handle until the ram
completes its full travel. Repeat as necessary.
If this procedure does not remove air, remove
plunger (24) and fill plunger cavity with clean oil
as outlined in Reassembly in the Maintenance
section of this manual.
4. Fill rubber bladder to the point of overflow and
replace bladder plug. Wipe bladder clean of excess
oil and reassemble reservoir handle.
Troubleshooting And Repair
To function properly, the punch driver must be free of
oil leaks, must build oil pressure, and the ram section
(right angle head) must rotate by hand force.
Oil Leaks
Check for external oil leaks.
Check that release valve knob and stem are closed
tightly and seating properly.
Remove reservoir handle (21) and check for oil leaks
around bladder (29) and bladder plug (20).
Greenlee Textron / Subsidiary of Textron Inc.
7904SB/7906SB Hydraulic Punch Driver
Failure to Build Pressure
Fill with oil and purge air from the system.
See Adding Hydraulic Oil.
Ram Section Will Not Rotate
Loosen and readjust set screw (13). Hold punch driver
with ram section down. Apply small amount of penetrat-
ing oil to cylinder (1) at the attachment point, then work
ram section back and forth. Apply a small amount of
SAE 30 oil to cylinder collar next to the pump block.
Rebuilding
If no leaks are visible and the unit will not build oil
pressure, disassemble and rebuild the punch driver.
Disassembly—Pump
Note: Separate ram section from pump section.
Remove set screw (13). Unscrew ram
section from pump section.
1. Remove reservoir handle (21), and bladder plug
(20); drain oil from the bladder (29).
2. Remove O-ring (35) and the bladder (29). Remove
retaining rings (37) from one end of both handle
pins (30) and remove handle pins and handle (22).
3. Grasp plunger (24) with pliers; pull and twist to
remove. Loosen set screw (12) from release valve
knob (27); remove knob. Unscrew release stem (28)
to remove from pump block (2). Remove retaining
ring (41) and oil filter (40). Unscrew inlet check seat
(23) and remove ball (32), and retaining ring (31).
Unscrew jam screw (26). Remove spring (39)
and ball (6).
Disassembly—Ram
Note: See illustration on the next page.
1. Thread an installation rod into the tapped hole
in ram (3). Place a flat washer and threaded
hex nut on the installation rod. Tighten the nut until
the spring retaining plate (4) is no longer applying
force against the retaining rings (5).
2. Remove the retaining rings (5) from the installation
rod and remove the spring retaining plate (4) and
compression spring (7).
3. Screw a draw stud into end of ram (3); push the ram
out of the cylinder (1).
You have now disassembled the punch driver.
Thoroughly clean all parts and inspect the three
ball seats (intake, discharge and release stem)
for nicks, scratches, or other damage.
10 4455 Boeing Dr., Rockford, IL 61109-2988 815/397-7070