MICROMATIC ROTAC SB-18 Operating instructions

RM – 26-10-7707 Rev. E Page 1 of 39
REPAIR MANUAL
ROTAC Models:
SB-18 & SB-18.2
Bills of Material Part Numbers:
Micromatic # / Bromma Article #)
For further information contact:
MICROMATIC LLC
525 Berne St.
Berne, IN. 46711-1298
Ph 260 589 2136 Fax [phone]
www.micromaticllc.com

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REVISION HISTORY
REV. DATE DESCRIPTION BY
A 11DEC20
REVISED / ADDED INSTRUCTIONS REGARDING ECO 11815 & 11864
;
1/2 - 13 TORQUE WAS 126 FT∙LBS, NOW 93 FT∙LBS
STINSON
B 02SEP21
REVISED/ADDED NEW ASSEMBLY TOOL KIT REGARDING ECO
12151; TOOL KIT PART NUMBER IS
26-97-0348 AND 26-97-0349; TOOL NUMBER SK-4133 IS NOW
REPLACED BY SK-5238-02
LUTHMAN
C 10SEP21 REVISED ASSEMBLY TOOL KIT BY ADDING TWO A010152 DOWEL
PINS TO THE BOM
LUTHMAN
D 11FEB22 REMOVE SEALS A010263, A010264, AND 26-09-0714; THEY NEED
REPLACED WITH 26-09-2813 SHAFT SEAL AND 26-09-0539 O-RING
REGARDING ECO 12368
LUTHMAN
E 15MAR22 REMOVE SEALS 26-09-2813 SHAFT SEAL & 26-09-0539 O-RING,
REPLACED BY SOLUTION USING 26-09-2901 & 26-09-2941 PER ECO
12452; 1/2 - 13 TORQUE WAS 93 FT∙LBS, NOW 115 FT∙LBS
STINSON
F 05AUG22 COMPLETELY REWRITTEN WITH ADDED GRAPHICS AND STEP BY
STEP DIRECTIONS. ADDED GEN2 SB-18.2 MODELS (26-10-7747 &
26-10-7748)
BIVENS

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INDEX OF SECTIONS
1) INTRODUCTION
2) DISASSEMBLY
3) EVALUATION AND CORRECTIONS
4) PREPARATION AND SEAL INSTALLATION
5) ASSEMBLY WITH ASSEMBLY TOOLS
6) ASSEMBLY WITHOUT ASSEMBLY TOOLS
7) REFERENCE INFORMATION AND SPECIFICATIONS

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1) INTRODUCTION
a) This document provides disassembly, inspection, assembly procedures and other relevant
information for TWO generations of the SB-18 ROTAC® Rotary Actuator model exclusively
manufactured for BROMMA:
i) 1st Generation (GEN1) = SB-18-1V-DE-FLATS-FT and SB-18-1V-DE-KEY-FT
(1) 26-10-7707 (BR1002277) shaft with flat ends
(2) 26-10-7712 (BR1001276) shaft with round end and key slots
ii) 2nd Generation (GEN2) = SB-18.2-1V-DE-FLATS-FT and SB-18.2-1V-DE-KEY-FT
(1) 26-10-7747 (BR1709884) shaft with flat ends
(2) 26-10-7748 (BR1709888) shaft with round end and key slots
b) Actuator servicing should not be attempted without a new seal kit
i) Reference SECTION 7 for seal kit numbers.
c) Assembly with and without tools
i) It is highly recommended to use assembly tools – SECTION 5
(1) Reference SECTION 7 for assembly tool kit part numbers.
ii) To perform assembly without tools – SECTION 6.
d) Terminology
e) GEN2 differences and compatibility with GEN1:
i) Assembly:
(1) GEN2 assembly IS a direct fit / completely interchangeable with GEN1.

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ii) Shaft:
(1) GEN2 Includes two (2) wear pad mounting slots on both sides of the vane.
(a) Four (4) pads total in assembly for axial wear control.
(2) The shaft with and without wear pads IS interchangeable between Gen1 and Gen2
models.
iii) Heads:
(1) GEN2 heads have Journal bearings pressed in head.
(2) GEN2 Shaft seal grooves are different in size and quantity.
(3) GEN2 head IS interchangeable onto Gen1 when using GEN2 shaft seals.
iv) Shaft Seals:
(1) GEN2 has new material, size and quantities of seals used.
(2) GEN2 seals are NOT interchangeable with Gen1 heads.
v) Shoulder Seal:
(1) Additional wavy spring energizer per side, total of four (4) per actuator assembly.
(2) GEN2 wavy spring and quantity IS interchangeable with GEN1 heads and assemblies
vi) Pressure Relief Cartridge:
(1) Same function and pressure settings.
(2) GEN2 cartridges are NOT interchangeable with GEN1 manifold.
vii) Manifold:
(1) Pressure cartridge cavities different, pressure relief cartridge specific.
(2) The manifold with the pressure relief cartridge installed IS interchangeable between
GEN1 and GEN2 models.
viii) External Shims
(1) GEN2 does NOT have the external shim discs that some newer GEN1 actuators have.
(2) GEN1 shim discs CAN BE installed on GEN2 actuators however they are not required.
2) DISASSEMBLY
a) Preparation:
i) Reference exploded view drawings for relative part locations shown in SECTION 7.
ii) A plastic or wood covered workbench is the best to avoid damaging parts.
iii) A work bench with a hole through it OR wooden blocks to act as spacers during the
assembly process is recommended.
b) Clean:
i) Clean the assembly area. This area MUST be clean to prevent contamination.
ii) Clean the exterior of unit thoroughly. Parts MUST be clean to prevent contamination.
iii) Cleanliness ensures contamination from small particulate matter does not lead to damage.

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iv) A clean disassembly helps to identify that any material found inside the actuator is a result
of wear, system contamination or damage. Ultimately, a more accurate evaluation of the
actuator and operating system will be obtained.
c) Mark parts:
i) Before disassembly, the body, heads, and shaft should be marked in such a way as to aid
in reassembly to return parts to their relative positions to avoid installing the shaft
backwards.
d) Shaft:
i) Remove all burrs and dings from all
exposed shaft edges, around key-
seats and end chamfers on both
ends of the shaft.
ii) Any raised ‘dings’ or burrs MUST be
addressed otherwise damage will
occur to the seals, seal glands and
the bearings as the shaft is removed
and reinserted.
e) Manifold Removal:
i) Remove six (6) SHCS bolts.
ii) Remove two (2) O-rings.
(1) Inspect O-rings for any damage.
(2) Clean O-rings.
iii) Remove cartridge only if necessary.
f) Head Removal:
i) DO NOT PRY HEADS OFF!!!
(1) Damage will occur to body or heads if you attempt to insert a pry tool between the
head and body to pry heads off.
ii) Remove assembly screws / head bolts from both heads.
(a) Removing material ‘smeared’ over the head bolts from high impact damage may be
required to access and remove bolts.
iii) Recommend removing head dowels.
(1) An air hammer is recommended to drive out head
dowels.
iv) Insert ½-13 screws (Jack Screws) into the two tapped
holes
v) NOTE: a plastic set screw/plug may need removed.
vi) Tighten each “Jack Screw” evenly and in an alternating
fashion so as to separate heads from body by evenly
raising the head off the body by using these two
screws as ‘jacks’.
vii) Alternate Method:
(1) Remove all Head Bolts AND four (4) long Head Dowels.

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(a) Removing material ‘smeared’ over the head bolts from high impact damage may be
required to access and remove bolts.
(b) An air hammer is recommended to drive out head dowels.
(2) With the unit standing upright, strike end of shaft with plastic mallet or non-marring
hammer and allow the shaft to push the opposite head/end off.
g) Shaft Removal:
i) Be certain to have addressed all dings and burrs as identified earlier.
ii) Pull the shaft out, with a straight even pull, taking extreme CAUTION that the shaft does
not fall and nick the body or damage the journals or ‘A’ diameter of the shaft.
iii) Remove all seals and inspect for cuts, nicks, or any other unusual conditions of the seal.
3) EVALUATION AND CORRECTIONS
a) Examine oil residue inside actuator. This may give a clue as to why any damage has occurred.
b) Contaminated oil will cause scoring of internal surfaces.
c) Varnish on internal parts can be a sign of hydraulic system running too hot.
d) Metallic particles may originate from valve spools, actuator internal parts and hydraulic system
components.
e) The appearance of any contamination will require flushing and cleaning of the hydraulic
system.
f) Remove shaft seals and closely examine seal grooves for any corrosion, contamination, or
damage.
g) Wash all parts thoroughly and examine for defects.
h) Shaft:
i) Shaft should be thoroughly cleaned of all contamination.
ii) All critical areas of shaft addressed as identified earlier
iii) Care must be taken to not damage the shaft – especially the edge of the ‘A’ diameter and
the shaft journals (see Shaft Diagram).
iv) Cracks:
(1) Examine the vane for cracks on "A" diameter,
keyways, and other areas where stress may be
applied.
(2) Spot check by Magnaflux can be used to check for
cracks. FOLLOW DIRECTIONS ON BACK OF
THE CANS CAREFULLY.
v) Corrosion:
(1) Rust will likely be present on the shaft at edge of
the outer seal. This area should be lightly
polished in a radial direction to remove the rust.
(2) ANY polishing or clean up performed on the shaft
must be performed in a radial fashion to prevent
linear scratching.
(3) A fine polishing paper or ‘Scotch Brite’ pad of 600 grit or higher can be used.

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(4) Using a lower grit to polish the shaft can lead to shaft seal leaks.
vi) Scoring or galling:
(1) Check side faces of the shaft vane and side faces of the ‘A’ Diameter for scoring or
galling.
(a) Any scratches or galling of the part which are .010 in (0.25mm) or more deep
requires replacement of the part.
(2) It is possible to refurbish shafts however, it is recommended that this type of repair be
performed by the actuator factory or a highly qualified source.
vii) Inspect Shaft Journal Diameter:
(1) The Journal Diameter of the shaft is a Critical
dimension that MUST be maintained.
(2) Using a pair of micrometers measure the diameter of
the shaft journal approximately ½ in (12mm) from
outer edge.
(3) Refer to SECTION 7 at the end of this document for
specifications on the maximum and minimum
allowable diameters.
(4) Replace the shaft if its size is out of specifications.
viii) Round shafts with key slots:
(1) If the key seats are widened it will allow the key to
move, damaging mating coupling and ultimately
cause failure of the shaft and/or mating part.
(2) Key slot width specification is 0.7894/0.7874 inches.
i) Body:
i) Edges
(1) Edge where body bore meets side face of body
MUST be ‘sharp’ without a radius or burrs.
(2) Shoe seal groove edges should not have any burrs.
ii) Scoring
(1) Any light scoring can be polished out with 400-grit
emery cloth or equivalent.
(2) Scoring of .010” or more deep indicates
replacement of this part is necessary.
(3) When pressurized, the body will expand and
contract. For this reason, plating is not
recommended by the factory for repair.
iii) Cracks may be found across the dowel holes, screw
holes or ports. This indicates replacement is needed.
iv) Dowel holes may be elongated or out of round. This
indicates replacement is necessary.

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j) Heads:
i) Scoring on face of head MUST be repaired.
ii) Journals:
(1) Measure the diameter of the journal.
(2) Refer to SECTION 7 at the end of this
document for the specifications for maximum
and minimum allowable diameters.
(a) GEN1 heads require replacement if they
are out of specification.
(b) GEN2 heads can be serviced by removing
and replacing the journal bearing and final
machining it to the specified diameter.
iii) Seal Glands
(1) Corrosion and other contamination MUST be removed from the seal grooves.
(2) Seal Gland edges must not have any burrs or other damage.
(3) The edge of the seal glands are NOT to be heavily rounded.
k) Seals:
i) Do NOT reuse seals - all seals should be replaced!
ii) Refer to the Seal Kits Table in SECTION 7 Section at the end of this document.
iii) Compare to the new seal kit – Note: There may be additional seals not used.
iv) Cutting or shaving of seals can occur during disassembly if extreme care is not taken. This
can occur in several different ways and will lead to reduced actuator performance and is
why seals should not be reused.
v) Refer to assembly instructions for proper procedure.

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SEAL REPLACEMENT AND REASSEMBLY
4) PREPARATION AND SEAL INSTALLATION
a) Complete guidelines specified in the Evaluation and Corrections Section
b) Parts should be re-cleaned if necessary.
c) Ensure shaft journals at seal areas have not been scratched.
d) A small pliable brush or non-lint towel with a high flash point solvent should be used to clean
seal grooves, dowel holes, screw holes and other hard-to-get-at areas.
e) Remove all burrs that may be on any part.
f) DO NOT break corners on Shaft "A" diameter or heads of the body I.D. These sharp corners
are important to the operation and function of the actuator. They should be sharp but also burr
free.
g) Seal Installation into parts is common between assembly methods with assembly tools
and without assembly tools.
h) Vane Seal Installation:
i) Install rubber vane seal energizer
ii) Install vane seal cap which has ‘Earmuff’
shape.
(1) Vane cap MUST be a press fit into
corresponding pockets on shaft.
(2) If necessary, VERY LIGHTLY tap
‘Earmuffs’ with a flat hammer to slightly
enlarge ‘Earmuff’ diameter.
(3) Use wooden handle of hammer to press seal ‘Earmuff’ of seal into pocket of shaft.
(a) Slight ‘skiving’ of the seal by the sharp edge of the pocket is ideal.
(4) ‘Earmuff’ portion of seal should NOT easily come out of pocket in shaft when long leg
of the seal is lifted on.
(5) The ‘Earmuff’ portion of the vane seal cap is the ONLY portion of the seal which should
‘Stick’ in the corresponding vane groove. The rest of the vane seal cap should be free
to float in the shaft groove.
i) Shaft Seal Installation into Heads (x2):
i) Check seal groove edges and remove any burrs, dings,
or nicks.
ii) Thoroughly clean seal groove(s) with high flash point
solvent and non-lint cloth.
iii) ‘Kidney Bean’ the seal to aid installation. See image.

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iv) GEN1 SB-18 Actuator:
(1) Install Back-up Ring and O-ring (Item #25 & #24) into groove in head.
(2) The Back-up Ring (Item #25) MUST be against outside wall of groove.
(3) The O-ring (Item #24) installs into the same groove as Item #25 and MUST be on the
inboard position and the groove.
(4) CRITICAL: AFTER the seals are installed, lightly coat the entire exposed surface of
the O-ring with clean hydraulic oil.
v) GEN2 SB-18.2 Actuator:
(1) Install O-ring into innermost and outermost seal grooves.
(2) Install seal cap over O-rings.

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(3) Use the ‘Kidney Bean’ method for deforming seals to fit into seal groove.
(a) NOTE: If seal is kinked or damaged during installation it MUST be replaced to
avoid external hydraulic fluid leaks.
(4) The middle seal groove is not used; however, it is sized to accept the shaft seal parts
in the event there is damage to one of the other seal glands.
(5) CRITICAL: AFTER the seals are installed, lightly coat the entire exposed surface of
the seal caps with clean hydraulic oil.
vi) GEN1 SB-18 Obsoleted Seal Versions
(1) Older actuators may have different seals in them than shown above.
(2) The older actuators have improved shafts and these seals in them and are designated
with a ‘C’ on the end of the shaft as shown in the image below.
(3) There are two different variants older models may have.
(a) Variant 1 = O-ring and “L” shaped Seal.
(b) Variant 2 = Orange Spacer, O-ring and Seal.
(c) Variant 3 = O-ring and Back-Up Ring.
(d) Refer to images below for each of the obsoleted variants.
(4) In the instances of older units with these shaft seal variants, the seals and seal kit
identified for GEN1 SB-18 are replacements for these seals.
(5) Refer to SECTION 7 for more information on seals and kits.

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j) Shoulder Seal Installation into Heads (x2):
i) Ensure there are no dings or
rounded edges on the shoulder
seal pocket.
ii) Place wavy spring(s) (Item #20)
into pocket in head.
(1) GEN1 has one (1) wavy
spring / side
(2) GEN2 has two (2) wavy
springs / side
iii) Install hub seal ring (Item #19) on
top of wavy spring.
iv) Install shoulder seal (Item #18) on
top of the shoulder seal ring into
the diameter of the pocket in the
head.
(1) Ensure that hub seal (Item
#18) has a tight diametrical fit to the pocket in the head.
(2) If necessary, SLIGHTLY stretch the seal to ensure the diametrical fitment is snug.
(3) The shoulder seal should be free to move in and out of the pocket when pressed upon.
If seal sticks down / into the pocket when pressed, the cause must be remedied.
(4) The fitment of seal is essential to the proper performance of the actuator.
v) Note: Brushing a light layer of assembly grease, petroleum jelly, over seal onto head will
help retain seals for installation in a later step.
k) Head Seal Installation into Heads (x2):
i) Place head seal (O-ring) into the head seal groove in each head.
ii) To assist with assembly of the O-ring wanting to pop out of the D-shaped groove:
(1) Brush a light layer of assembly grease (petroleum
jelly) into the groove.
(2) Place the O-ring down into the groove in the long
straight section first.
(3) Use one hand with fingers spread as wide as possible
to hold the seal down into the groove.
(4) Use other hand to grasp the opposite side of the O-ring
outward beyond the seal groove towards the opposite
side with the radius.
(5) Allow the O-ring to slowly relax and guide it into the
grove simultaneously.
(6) Brush a light layer of assembly grease (petroleum jelly)
over the entire surface of the head seal O-ring.
iii) Set heads aside to use later in assembly onto the body.

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5) ASSEMBLY WITH ASSEMBLY TOOLS
a) It is recommended that assembly tools be used to assemble the actuator.
i) The assembly tools simplify assembly and significantly reduce the likelihood of damaging
critical parts and features during the assembly process.
b) A following Section below outlines a method to assemble the actuator without assembly tools.
c) Assembly tool kit part numbers are identified in SECTION 7.
d) Differences between GEN1 SB-18 and the GEN2 SB-18.2 models are outlined below.
e) Reference the Exploded View sheets in SECTION 7 for Item #’s.
f) Assembly Tool Kits:
i) There are two different assembly kits available for each shaft end type (Flat or Round).
Reference the Assembly Tools figures.
ii) A detailed Bill of Material for the tool kits is available in SECTION 7.
iii) During the assembly of the unit, the seals MUST be protected to avoid damage – the
assembly tools provide the highest level of protection.

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iv) If necessary, to temporarily ‘Hold’ parts in place, for example the dummy half keys,
petroleum jelly can be used.
(1) The ‘Earmuff’ portion of the vane seal cap is the ONLY portion of the seal which should
‘Stick’ in the corresponding vane groove. The rest of the vane seal cap should be free
to float in the shaft groove.
g) “Dummy Head” (SK-4312), “Dummy Dowels” (A010152), Bolts (26-12-0141) Tools:
i) Refer to Section 6 to assemble without using
assembly tools.
ii) Check both sides of Body at the edge of the internal
bore to the outer wall and ensure there are no burrs,
nicks, or other defects. This edge MUST remain
SHARP and without any radius or chamfers.
(1) If this edge is rounded or damaged in any way,
the performance of the actuator will be
significantly degraded.
iii) Orientation of Body:
(1) Lay the Body onto a flat surface as shown in
“Orientation of Body” image. The head dowel
hole on the right side should be lower than the head dowel hole on the left side.
iv) Place Dummy Head on top of body and line up the
two opposing dowel holes.
v) Insert BOTH Dummy Dowels through the head into
the Dummy Head to align the two parts.
vi) Install both SHCS Bolts (1/2”-13 UNC) through the
clearance holes in the Dummy Head and into the
threaded holes in the Body to fasten Dummy Head
onto actuator Body.
vii) Remove Dummy Dowels.
viii) Flip the assembly of the Body and Dummy Head
over such that the Dummy Head is on a flat surface.
h) Shoe Seal and Cushion Installation:
i) Ensure shoe seal groove is free of any burrs,
nicks, or contamination.
ii) Install the shoe seal cushion and shoe seal cap
into the seal grove.
iii) Assembly grease like petroleum jelly can be used
to hold the seal in place
iv) Lubricate the shoe seal cap and the ID of the body
(Item #1).
v) Insert the vane seal cushion and "C" shaped shaft
vane seal cap in the vane seal groove.
vi) Apply assembly grease (Petroleum Jelly) as
necessary to hold the seals in position.
i) Vane Seal Protector Tool (SK-4318):

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i) Refer to Section 6 to assemble without assembly tools.
ii) Place the assembly tool “Vane Seal Protector” on top
of the body and align the two opposing dowel holes.
(1) NOTE: MUST ensure the vane seal protector
edge that has a ‘Tapered Lead In’ is on the TOP
side and away from the Body. This tapered lead
in aids installation of the shaft.
iii) Insert the two “Dummy Dowels” through the dummy
head holes and into the corresponding body holes to
align the two together.
iv) Feel the transition at the joint between the Body and
Vane Seal protector and ensure a smooth transition.
(1) The diameter of the body shall NOT be
smaller/inside of the vane seal protector as this
WILL damage the vane cap seal on the shaft
during installation.
j) Shoe Seal Protector Tool (SK-5238-02):
i) Refer to Section 6 to assemble without assembly
tools.
ii) Workbench with hole in it or spacer blocks is
necessary at this step.
(1) The actuator assembly tools build the actuator on
its side. Therefore, the shaft of the actuator
protruding from the heads require either a hole in
the workbench or spacer blocks to be placed
under the Dummy Head”
iii) The Shoe Seal Protector prevents the shoe seal from
being cut/skived by the sharp edge of the ‘A’ diameter
of the shaft during installation. Failure to protect the
shoe seal cap seal during installation will result in
damage and poor actuator performance.
iv) Orient the Shoe Seal Protector such that the tapered lean-in edge is at the top and the
radiused edge is pointing down and then insert the Shoe Seal Protector partially down into
the hole in the dummy head.
v) Newer tool kits have an O-ring in the hole of the dummy head that will grip and hold the
shoe seal protector in position.
vi) For older tool kits that do not have the O-ring in the dummy head slide the shoe seal
protector over the shaft journal with the shaft oriented as shown in the next step for shaft
installation.

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k) Shaft Installation with Tools:
i) Refer to Section 6 to
assemble without assembly
tools.
ii) Flat End Shafts:
(1) The hole in the flat of
the shaft end MUST be
oriented as shown.
iii) Round End Shafts:
(1) The key slots in the
shaft MUST be oriented
as shown.
iv) To ease installation, position the shaft such that the vane points mostly to the side relative
to the ports on the body as shown.
v) Slide the shaft down into the Shoe Seal Protector sleeve that is held in the Dummy Head.
(1) Alternatively: Slide the shaft with the shoe seal protector on the journal down into the
hole in the Dummy Head.
vi) CAUTION: The Shoe Seal Protector Sleeve will fall if the Dummy Head tool being used
does not have the O-ring feature to hold it. Therefore, take steps to prevent tool from
being dropped and damaged by placing a towel or something similar under it.
vii) Lower shaft until the vane comes to rest on the Dummy Head.
viii) Verify the vane cap seal has not come out of the seal pocket.
l) Bearing pad Installation:
i) GEN2 Actuators - Place two (2) bearing
pads A010269 (item #25) into each of the
grooves in the side face of the shaft vane as
shown.
(1) Pads will freely move in grooves.
(2) Pads MUST be slightly proud / above the
surface of the shaft vane, use thumb nail
to verify.
ii) GEN1 Actuators - Do NOT have bearing
pads. External disc shims are installed on
the outside of the assembly.
iii) IMPORTANT: NOT INSTALLING PADS
WILL LEAD TO ACTUATOR FAILURE.
m) Head Installation with Tools:
i) Remove the following tools, set aside in a safe location:
(1) Vane Seal Protector
(2) Two (2) Dummy Dowels
(3) Shoe Seal Protector Sleeve
ii) Identify proper head for 1st installation:
(1) Refer to image for Head Identification.

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(2) Verify fitment by evaluating dowel hole positions.
(3) If the incorrect head is used, the mounting and dowel holes
will not line up.
iii) Select Shaft Dependent Shaft Seal Protector Tools:
(1) Flat End Shafts use the SK-
4391 Shaft Seal Protector.
(2) Round End Shafts use the SK-
3229 Shaft Seal Protector.
iv) Insert the appropriate Shaft Seal
Protector Tool into the head as
shown.
(1) IMPORTANT: Ensure that the shoulder seal parts are not
dislodged from pocket in head.
(2) NOTE: It is recommended to insert the Shaft Protector
Tool into the head vs onto the shaft to reduce the potential of dislodging the shoulder
seal parts during head assembly onto the body.
v) Dummy Key Tool install for Round Shaft Ends:
(1) Brush a LIGHT layer of assembly
grease (petroleum jelly) into key
slot in shaft. The grease will hold
the dummy key into place during
assembly.
(2) Press Dummy Key Tool SK-4399
into slot in shaft ensuring it is fully
flush with shaft. Extra pressure
will be necessary to squeeze out
grease and fully seat the key.
(3) Verify key is flush with surface of
shaft, if raised. press firmly to
squeeze out excess grease.
(4) IMPORTANT: Dummy Key must
NOT be raised above surface of
shaft. Failure to adhere to this will
result in damage to the shaft seals and an external hydraulic fluid leak.
vi) Carefully pick up the head with two hands opposite one another, align the Shaft Seal
Protector Tool with shaft, and SLOWLY lower the head down over the shaft.
(1) Resistance may be encountered at various points while lowering the head, this is
normal as the seals pass over edges on the shaft. LIGHTLY increase force to
overcome resistance.

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(2) CAUTION: Excessive force, speed or tapping
could dislodge seals.
(3) CAUTION PINCH HAZARD: Fingers can be
pinched if head is allowed to fall uncontrolled
onto the body.
vii) While there is still a gap between the head and
body, look inside to ensure shoulder seal parts
and head seal have not shifted and become
dislodged.
viii) Carefully remove one hand and grasp the raised
flange portion of the head where the mounting
holes are located to control speed of lowering
head onto body. Remove fingers from gap prior to
completing the lowering of the head onto the body.
ix) Insert Dummy Dowels:
(1) Once head is fully seated onto body, rotate head
as necessary to align dowel holes and fully insert
two (2) Dummy Dowel Tools.
x) Install two (2) head bolts:
(1) Apply medium strength thread locker to the ends of
two (2) ½-13 x 1.75” long head bolts and tighten
each bolts lightly snug – DO NOT fully torque bolts.
(a) NOTE: Final Torque and remainder of bolt
installation is completed at a later step.
xi) Remove tools and set aside:
(1) Two (2) Dummy Dowels
(2) Shaft Seal Protector
(3) Dummy half key for Round End Shafts
(a) NOTE: To remove Dummy Keys, thread in #10-32 bolt and pull to remove key.
xii) Remove Dummy Head Tool:
(1) Flip the assembly over such that the Dummy Head tool is on the top side.
(2) Remove the two (2) SHCS bolts holding the Dummy Head Tool onto the body.
(3) Set aside the Dummy Head and two (2) SHCS bolts.
xiii) REPEAT STEPS above for second
head installation.
(1) IMPORTANT: BE CERTAIN TO
INSTALL THE TWO (2)
BEARING PADS INTO THE
GROOVES IN SHAFT VANE.
xiv) Verify Shaft Orientation:
(1) Flip Actuator up such that it is
setting on the mounting feet.
(2) Shaft should be positioned as
shown it the Shaft Orientation
image for both shaft types.

RM – 26-10-7707 Rev. E Page 20 of 39
n) Head Dowels and Bolts Installation:
i) Flip Actuator up such that it is setting on the mounting feet.
ii) Install four (4) head dowels:
(1) Head dowels are to be a slight press fit. DO NOT ream
or enlarge dowel holes in actuator to make dowel
installation easier. Doing so will void warranty and result
in poor actuator performance and likely failure.
(2) It is recommended that the dowel pins be frozen to
negative 67°C to ease installation.
(a) Alternatively, the dowel holes can be lubricated with oil.
(3) Place one dowel into dowel hole with the slight
chamfered end being put into hole and the large
radiused / curved end outward.
(4) While actuator is laying securely on the side face of the
head, NOT the shaft, use a hand sledgehammer to
pound dowel down into the hole.
(5) Use an air hammer with a round pointed end to finish
driving dowel down into the hole such that the dowel is
equal distance from protrusion of the head on both
sides.
(6) Repeat for the remaining three (3) dowels.
iii) Install remainder of head bolts:
(1) It is recommended NOT to reuse head bolts.
(2) Apply medium strength thread locker to the ends of twelve (12) of the ½-13 x 1.75”
long head bolts and tighten each bolt snugly.
(3) Repeat thread lock application and installing head bolts on opposite side of the
actuator.
(4) Use torque wrench and top torque ALL head bolts on BOTH sides of the actuator to
torque specified in the Torques chart located in SECTION 7.
iv) Install four (4) Head Plugs:
(1) NOTE: Older actuators will not have these plugs
(2) Two (2) plugs per side into the head. Tighten until snug,
do NOT overtighten.
o) Pressure Relief Cartridge:
i) Refer to the parts listing on the Exploded Views for part
numbers