Gradall LOED 534A Service Manual - Manual (Page 43)

Clean all parts in solvent and blow dry with com-
pressed air. Inspect all parts and if any are found
to be worn or deformed replace them with new ones.
Clamp tang end of plunger (No. 4) in a vise. To
clean the pilot hole (No. 27) that runs down through
the inside of the plunger to the cross hole (No. 28),
use a rod or a drill with an O.D. approximately the
same size as the hole. Insert the instrument through
the passage several times being careful at all
times not to mar the seat on which the poppet rests.
To clean the cross hole at the bottom of the pass-
age, use an instrument in the same fashion as
previously described. Now blow the entire passage
out with compressed air.
Insert the small spring (No. 16) over the end of the
small poppet (No. 17). Now insert the small spring
guide (No. 18) into the other end of the spring.
Take this assembly and slip it into the sleeve
(No. 15) with the poppet exposed. Insert the adjust
rod (No. 13) through the hole in the end of the
sleeve. The cam (No. 14) now slides over the
adjust rod, and the larger spring (No. 12) slides
over the end of the cam.
Insert this assembly into the end of the plunger
(No. 4), making sure that all parts stay in align-
ment. Do not insert this assembly too far or the
ball holes (No. 29) will be closed off by the cam
(No. 14).
Form a cup around the ball holes (No. 29)
your finger and slowly insert the balls (No. 10). If
any difficulties are experienced in keeping the
balls in place apply a small amount of grease
(lubricate #630-AA) in the ball holes. While
holding the balls, slip the detent sleeve (No. 9)
down over the plunger (No. 4) gently pushing your
fingers off the balls while at the same time the
balls are being inserted into the detent sleeve.
Once the balls are inside the sleeve take your
thumb and apply a little pressure on the spring
(No. 12) and gently move the sleeve untit you feel
the balls positioned in the detent sleeve.
Since the seal and wiper (No. 26) at the tang end
of the valve need not be removed when servicing
the automatic kickout assembly, no instructions
are needed at this time for their removal or as-
sembly. If this seal and wiper do require inspection
or repair, proceed as per instructions on page B-10
and Figure #12, page 15.
MAINTENANCE PROCEDURE - FORWARD - REVERSE VALVE
(Reassembly)
Take the plunger (No. 4) out of the vise and dip
the tang end in oil. Now gently insert it into the
plunger bore of the housing (No. 11) being careful
not to move the detent sleeve (No. 9). Insert the
plunger into the bore until the detent sleeve
touches the counterbore of the housing. Now gently
push forward on the sleeve and the plunger
until the “O” ring (No. 19) on the detent sleeve is
seated in the counterbore. Use a left-to-right half-
rotation motion when inserting the “O” ring on the
cam (No. 14) into the counterbore. Do not force the
“O” ring into the counterbore.
Put the seal plates (No. 8) over the plunger (No. 4)
onto the detent sleeve (No. 9). Now install spring
guide (No. 7), spring (No. 6), and another spring
guide. Insert special cap screw (No. 5).
Insert round hardened rod through tang holes in end
of plungers (No. 4). This will prevent the plungers
from rotating. Be sure the valve is bolted to the
mounting plate or secured in some fashion that,
when pressure is applied to the special cap (No. 5).
your valve will not move.
Take spanner wrench and insert it into end of
special cap screw (No. 5) and force the spring and
screw up to the threaded end of the plunger (No. 4).
Make sure that all parts are aligned and proceed to
tighten all parts together. Brush a light coating of
grease on the large plunger spring (No. 6) and insert
your plunger cap (No. 3) over the spring, Insert
socket head cap screws (No. 1) through cap into
spacers (No. 2) and tighten socket head cap screws
to the valve housing.
Remove the rod from the tang end of the plungers
and rotate the plunger from the tang end, making
sure that the plunger turns freely. If plunger should
bind, re-adjust special cap screws (No. 1). Holding
the cap, insert linkage through tang hole in plunger
and move plunger in and out, making sure that the
detent action and the spring return is functioning
properly. If they do function normally, you know
the plunger has been reassembled properly.
To reset the kickout pressure setting, first install
a pressure gage in the cylinder port line, which is
in communication with the cylinder port for this
plunger. Move the plunger into an operating position
and apply pressure at high idle. Adjust in this
manner until desired kickout pressure is reached.
Never set the plunger kickout pressure higher than
the main relief valve pressure setting.
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
Step 7:
Step 8:
Step 9:
Step 10:
Step 11:
Step 12:
43
FIGURE 42