THIS
MODEL
HAS
BEEN
DISCONTINUED;
SEE
G686B
‐
S
FOR
REPLACEMENT
5
O V E R H A U L
The disassembly and re-assembly pro-
cedures can be accomplished by following
the instructions and the drawi n g s o n
p a g e s 1 1 a n d 1 3 .
U s e extreme
care during disassembly and re-
assembly not to mar, nick or burr any
smooth surface that comes i n
c o n t a c t w it h O - r i n g s .
B e f o r e
installing O-rings, be sure to apply an O-
ring lubricant. It is recommended that
special assembly tools, which can b e
o r d e r e d u n d e r p a r t n u m b e r
G685KT,
be used to overhaul this tool.
Service kit,
G686B-SKS
(which contains a
complete set of O-rings, backup rings,
screws, washers and gaskets) should be
ordered. The 680A159 setting gage is
included with the G685B-S tool.
A I R V A L V E S U B - A S S E M B L Y
To disassemble
First disconnect tool from its air source.
Remove retaining ring (78) and muffler (77). Insert a valve plug extractor (P-1178) or a 5/16-18 threaded rod or bolt into end
of valve plug (76) and pull it out. Using the same procedures, pull out valve spool sub-assembly (99).
NOTE: It should never be necessary to remove valve sleeve (69) unless the ports in the sleeve have become plugged from
contaminated air. The O-rings on this sleeve are static and hence do not wear.
If it is suspected that the ports are plugged, use needle nose pliers to grasp end of spring (70), turn clockwise and pull to
dislodge from groove in power unit.
With spring removed, the valve sleeve (69) can be pulled out using the valve sleeve removal tool (837B530).
To re-assemble
Reverse the above procedures being certain that all O-rings are properly lubricated. To avoid damaging the O-rings (71),
carefully install valve sleeve (69) with your fingers. Gently push and wiggle sleeve to allow O-rings to slip past inner ports.
The Spring (70) is best installed using a valve spring installation tool (836B530) to push the large diameter coil into the
groove. This requires care as the G685B-S will not operate if this spring (70) is not anchored firmly.
Prior to installing Plug (76) make sure that Plug, O-Ring (101) and the cavity in the handle is clean and free of grease.
After assembling the O-Ring (101) on the Plug, carefully push the plug in. Make sure to push all the way down, until fully
exposing the Retaining Ring Groove (careful use of a mallet is permissible).
Push the Muffler (77) in and carefully install the Retaining Ring (78) making sure it is securely snapped in.
H E A D S U B - A S S E M B L Y
Always remove the complete pulling head from the tool before attempting to disassemble the head assembly. Disconnect tool
from air source.
Remove the six socket head cap screws (82). Lift head assembly from the pistol grip (83). Remove O-rings (41). Empty the oil
into a container by draining from head, hoses and power unit. Dispose of oil according to environmental regulations.
Select a work table with a good vise. Place head cylinder (13) in the vise with the front end cap (3) of the head cylinder (13)
up. Tighten the vise securely.
THE G685KT TOOL KIT
