Komatsu 830E-AC Shop Manual page 762

Installation of Check Balls and Plugs in Quill
The check balls (4, Figure 8-20) in the side of the
quill assembly (2) are held in place with threaded
plugs (3).
If a plug is missing and the check ball is not found in
the cylinder, the opposite side hoist cylinder and the
plumbing leading to the hoist valve should be exam-
ined for damage. The hoist valve itself should also be
checked to see if the ball or plug has caused internal
damage to the spool. Peening of the necked down
sections of the spool may result. Spool sticking may
also occur under these circumstances.
Refer to Figure 8-21 for SS1158 tool that can be
made for installing or removing the check ball plugs.
Plugs should be checked during any cylinder repair
to be sure they are tight. If found to have any move-
ment, they should be removed and the ball seat in
the quill checked to see if it is deformed.
• If deformation of the ball seat has occurred, the
quill should be replaced.
• If the ball seat area is not deformed, measure the
plug thickness as shown in Figure 8-20:
Older Plug is 0.25 ± 0.02 in. thick.
Newer plug is 0.38 ± 0.02 in. thick.
FIGURE 8-21. SS1158 PLUG INSTALLATION/REMOVAL TOOL
L8-20
1. Use the newer plugs and make certain threads
in quill tube and on plugs are clean and dry
(free of oil and solvent).
2. Use Loctite "LOCQUIC" Primer "T" (TL8753, or
equivalent), and spray mating threads of both
plugs (3, Figure 8-20) and quill assembly (2).
Allow primer to dry 3 to 5 minutes.
3. Apply Loctite Sealant #277 (VJ6863, or equiva-
lent) to mating threads of both plugs and quill
assembly.
4. Place check balls (4) in quill tube (2) and install
plugs (3) with concave side facing ball. Using
SS1158 tool, tighten plugs to 95 N·m (70 ft lbs)
torque. Allow parts to cure for 2* hours before
exposing threaded areas to oil.
* Note: If "LOCQUIC" primer "T" (TL8753) was not
used, the cure time will require 24 hours instead of 2
hours.
5. Stake plug threads in two places (between
holes) as shown in Figure 8-20 to prevent loos-
ening of plug.
If removal of the plug is necessary in a later rebuild, it
will be necessary to carefully drill out the stake marks
and destroy the plug. A new plug should be installed
and staked as previously detailed.
Hoist Circuit Component Repair L08038