16
Rev. 1/23
GB784SH INSTALLATION TOOL S/N: 1008 AND ABOVE
PLEASE CONTACT GAGE BILT FOR ALL OTHER SERIAL NUMBERS.
WARNING
:
Disconnect tool from its air source before disassembly.
CAUTION:
Spring piston (784124) will eject outward when removing piston cap (784108) during shift piston (784125) disassembly
OVERHAUL
1.
Remove nose assembly and adapter from tool before attempting disassembly of head cylinder (784221).
2.
Loosen and remove (4) button socket head cap screws (400061) and remove head cylinder (784221) from handle
-
machined (784309).
3.
Place head cylinder (784221) in a vise vertically with the front cap (784103) upwards.
4.
Remove front cap (784103) with socket wrench (784204) from service tool kit (GB784SHTK). Remove (4) piston stops (784107).
5.
Turn the head cylinder (784221) in the vise so the rear cap (784132) is upwards. Remove the (2) socket head cap screws (405334)
and adjuster knob assembly (784139) with a
3/32”
hex key. Remove the adjusting ring (784138).
6.
Remove the rear cap (784132). Push the head piston (784112) towards the rear to remove the shift piston (784125).
Note:
Valve (784116), valve seat (784119) and shift stop (784127) must be replaced as a valve assembly (784118).
The re
-
assembly sequence is the opposite of disassembly. (See Filling and Bleeding procedures pgs. 11
-
12). Apply Loctite® #242
and torque the button head cap screws (400061) uniformly to 40 inch lbs. (4.52 Nm) to prevent leakage around the gasket (745124).
HEAD
1.
Clamp the shift piston (784125) into the large hole of clamp wrench assembly (784201), locating on a polished surface. Tighten
the
cap screws on the clamp wrench assembly (784201) securely.
2.
Place the clamp wrench assembly (784201) in a vise so the shift piston (784125) is facing upward.
3.
Place shift piston tool (784203) over the threads and against the shoulder of the head piston (784112) to protect the seals.
4.
Remove the piston cap (784108) with a second clamp wrench assembly (784201) tightened around the smaller hole.
5.
Remove the valve seat (784119) with an
11/16”
wrench.
6.
Remove the valve (784116) and valve spring (784115).
SHIFT PISTON DISASSEMBLY
1.
Using a
5/32” (4
mm) hex key, turn socket head cap screw (405334), attached to adjuster knob assembly (784139), counter clock
wise until it stops. Remove the retaining ring (S768) with a sharp or pointed instrument. The socket head cap screw (405334) can
then be turned clockwise so the shift stop (784127) can be removed.
2.
Remove the shift screw (784128) with a
3/16”
hex key. Hold socket head cap screw (405334) with a
5/32” (4
mm) hex wrench.
3.
Remove the socket head cap screw (405334) and index washer (784136).
4.
Push the shift screw (784128) out.
5.
Remove the release piston assembly (784130) from the rear cap (784132).
Note: After servicing the tool, to reassemble, reverse the above procedures. Make sure to use proper tools and tighten all
parts to manual torque specifications. (See page 10).
REAR CAP DISASSEMBLY
