Gradall 534B (9103-1390) Service Manual - Manual (Page 88)

HOW TO TEST AND ADJUST
THE INCHING MECHANISM
In a safe area, drive the GRADALL Material
Handler and test the inching brake. If it is properly
adjusted you should be able to move the Handler very
slowly, and under full throttle. Attempt to inch while
turning a sharp turn. If the unit does not respond
smoothly, test and adjust as follows:
6. You are now ready to test the inching components:
11
Make sure the service brakes are functioning
properly.
I n s t a l l a 0 - 5 0 0 0 p s i t e s t g a g e i n t h e t u b e
coming from the #1 pump section. (A)
Install a 0-2000 psi test gage (G) in the test port
located in the front brake lines . Bleed the
brake lines.
Depress the Brake/Inching foot pedal to full
brake application. It should be 3/4" to 1" from
the floor. (C) Adjust the brake linkage, if needed.
Check the low torque inching switch adjustment.
It is located under the floor plate. This switch
should disengage with the first 1/4" to 1/2" of
brake/inching pedal movement. (D) Adjust if
needed.
1.
2.
3.
4.
5.
At the same time the gage (A) on the # 1 Pump
tube should read 1100+150 psi. If over or under,
mechanical adjustment of the inching linkage is re-
quired.
If the test gage reading is over 1250 psi, increase
l i k a g e l e n g t h t o i n c h i n g v a l v e b y a d j u s t i n g
yoke one turn and repeat test.
If the test gage reading is under 950 psi, decrease
the likage length to inching valve by turning
yoke one turn and repeat test.
After adjustment, test the Material Handler to
make sure it inches correctly. Remove gages and
recap test ports when test is completed.
7.
8.
9.
10.
Start engine and depress the service brake
oot pedal completely down.
Place gear shift in first gear forward with the
rear wheels straight.
Increase engine power to full rpm.
Back off on the brake pedal until the brake
ine gage (G) reads 300 psi.
HOLD PEDAL
IN THIS POSITION.
A.
B.
C.
D.
NOTE: Inching valve spool should not be bottomed
out against the stop in either direction. Machine must
be at full operating temperature before testing/adjust-
ing inching system.