Service
FS 105
May 2009
MAINTENANCE INSTRUCTIONS – HYDRAULIC ROTARY ACTUATORS
GENERAL
MOOG FLO-TORK ROTARY ACTUATORS REQUIRE CLEAN, FILTERED
HYDRAULIC OIL FOR SATISFACTORY OPERATION, THE SAME AS
ANY OTHER HYDRAULIC COMPONENT. THE STANDARD BUNA-N
SEALS ARE DESIGNED FOR PETROLEUM BASE FLUIDS. DURING
RE-ASSEMBLY, TORQUE ALL BOLTS IN ACCORDANCE WITH
TORQUE TABLE.
MODELS 900 THROUGH 30,000
MAXIMUM OPERATING PRESSURE: 3000 psi NON-SHOCK
KEY CONSIDERATION IN THE DISASSEMBLY OF THE UNIT IS DETERMINING THE PINION SHAFT
KEYWAY RELATIONSHIP TO THE RACK POSITION TO MAINTAIN PROPER TIMING AT RE-ASSEMBLY.
NOTE:
STANDARD UNITS ARE TIMED WITH THE PINION SHAFT KEYWAY AT 12 O’CLOCK
WHEN LOOKING AT THE BEARING CAP SIDE AS SHOWN ON THE ENCLOSED TYPICAL DRAWING.
DISASSEMBLY
1. Remove all cylinder head tie bolts/tie rods.
2. Remove cylinder heads.
3. Determine the rack is at mid-point of travel (equal amounts of rack
extended on each side of housing). Note and record pinion shaft
keyway location for re-assembly.
4. Back off the bearing cap set screw. Using a spanner wrench,
unscrew the threaded bearing cap from the housing.
5. Remove O-ring from housing.
6. Pull pinion from the housing with the bearing on it, placing unit
over a pan or tub as it is filled with gear lubricating oil which will
drain from the housing when the pinion is removed.
7. Remove the cylinder tubes.
8. Remove the piston/rack(s).
9. Remove the back bearing from the housing (if necessary).
10. Remove all remaining O-rings and seals. Replace with new O-rings
and seals at re-assembly.
11. Thoroughly clean and inspect all parts for wear or damage.
Replace with new parts as required. Lubricate with light oil before
re-assembly.
RE-ASSEMBLY
1. Install new O-rings, back-up rings and seals in proper grooves
(see drawing).
2. Install back bearing in housing.
3. Slide a cylinder tube over one end of the piston/rack assembly. If
it is a double rack unit, slide a cylinder tube over one end of the
second piston/rack assembly.
4. Slide piston/rack assembly and cylinder tube into the housing. If it
is a double rack unit, slide both piston/rack assemblies and cylinder
tubes into the same side of the housing.
5. Attach cylinder head(s) and bolts. Snug bolts up but do not torque
until re-assembly is complete.
6. Center rack in housing. (Equal spacing of rack on both sides of
housing.)
7. Install pinion with the shaft keyway location as noted during
disassembly. (Standard unit timing will have keyway at 12 o’clock
location when looking at the front mounting face.)
8. Install cylinder tube(s) on the other side of housing.
9. Attach cylinder head(s) and bolts. Snug bolts up, but do not torque
until re-assembly is complete.
10. Lay unit down and fill housing to top of the rack with ISO grade 68
gear oil or other equivalent gear lubricant.
11. Install front pinion bearing and O-ring.
12. Install bearing cap. Tighten bearing cap until snug, then further
tighten slightly to ensure a positive seal.
13. Insert nylon locking pellet in bearing cap set screw hole. Tighten set
screw locking bearing cap.
14. Torque cylinder head bolts evenly by applying force alternately to
opposite corners of the head. Torque values per bolt size are shown
in the torque table.
Moog Flo-Tork
1701 N. Main St. P.O. Box 68, Orrville, Ohio 44667-0068
PHONE: 330-682-0010 FAX: 330-683-6857
900-30,000
MODEL NO.
FASTENER SIZE
RECOMMENDED TORQUE FOR
CYLINDER HEAD BOLTS
900 & 1800
1/4 - 20
6
ft-lbs
3700 & 7500
5/16 - 18
12
ft-lbs
15,000 & 30,000
7/16 - 14
22
ft-lbs
TORQUE TABLE
