Cherry Aerospace G-689, Original Instructions Manual

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4
F I L L A N D B L E E D I N S T R U C T I O N S
To replace a small amount of oil in the tool, remove rear cap screw (39) located on the side of the head (13) being sure NOT to
cycle the tool. Attach the Cherry air bleeder (700A77), connect the tool to the air line and slowly cycle several times. This will
ensure the removal of any air from the hydraulic system and its replacement with fluid.
Should it become necessary to completely refill the tool (such as would be required after the tool has been dismantled and re-
assembled), take the following steps:
1. After removing the head assembly, fill handle (61) with the
recommended oil to within 1/8" (3.175 mm) of the top of the
handle casting.
2. Replace the head assembly, being sure gasket (88) and O-
Ring (87) are properly in place. Tighten cap screws (89 and
90) uniformly to prevent leakage around gasket.
3. Connect tool to air line and remove both cap screws (39)
from the side of the head assembly.
4. Using a pressurized oil can filled with Dexron III ATF (or
equivalent), force the fluid into the front hole until it flows
freely from the rear hole. Reverse the procedure until air
bubbles cease appearing at either hole.
5. Replace both cap screws (39), cycle the trigger several
times and then repeat steps 3 and 4 above.
6. To ensure the positive removal of all air from the hydraulic
system, we recommend the use of Cherry air bleeder
(700A77). Follow the instructions for the air bleeder above.
T R O U B L E S H O O T I N G
1. Check the air line for correct pressure at the tool. It must be
90 to 110 psi (6,2 to 7,6 bar).
2. Check for oil leakage:
•
Oil leaking around the cap screws (39) in the head
indicates that the screws are loose or the Stat-O-Seals
(38) need replacing.
•
If oil should leak through the by-pass hole at the base of
the handle (61) the O-rings (64) are worn or damaged.
•
Oil leaking from the front of the head (13) indicates that
O-rings (5 and 11) are worn or damaged; replace.
3. Check for excessive air leakage from the air valve:
•
If spring (73) is broken or dislodged, air will bleed directly
through the bottom of the air valve and the head piston
retreats to its full stroke without returning. See air valve
instructions on Page 5.
•
If O-ring (78) on valve plug (79) is worn or damaged,
replace.
•
If O-rings (74) on valve spool (75) are worn or damaged,
replace.
4. Check movement of head piston (14). If it does not move
freely or is slow in operation:
•
Valve stem (18) may be held off its seat (21) by
contaminants, allowing oil to by-pass. Drain tool, flush
thoroughly and refill with new oil.
•
O-rings (15) or (66) may be damaged and require
replacement.
•
Head piston (14) may be mechanically locked due to
damaged parts.
•
Muffler (80) or air filter (76) inside valve spool sub-
assembly (93) may be plugged with dirt. Clean them
thoroughly with normal solvent and back-blow with
compressed air.
•
Hole in metering screw (77) in valve spool sub-assembly
(93) may be blocked or damaged. Hole diameter should
be .028" (.7112 mm). Clear and size or replace valve
spool sub-assembly (93). Valve spool (75), metering screw
(77) and filter (76) are not sold separately.
5. Check movement of shift piston (24). If it does not move
freely:
•
The small hole in release piston sub-assembly (28) may
be plugged preventing oil flow. Drain gun, flush thoroughly
and refill with fresh oil. See Fill and Bleed instructions.
•
Hole through valve stem (18) may be plugged by
contaminants. Drain gun, flush thoroughly and refill with
fresh oil.
•
Pulling head components may need maintenance.
Disassemble the pulling head, clean and replace worn
parts. Re-assemble following instructions on page 10.