JLG 80HX_HX+6_HXER ANSI Service Manual User Manual
Page 108
SECTION 5 - HYDRAULICS
5-16
– JLG Lift –
3120271
5.8
RACINE PROPORTIONAL AIR GAP
ADJUSTMENT
NOTE: The assembly in Figure 5-11. includes select fit parts
in order to maintain a proper air gap. These parts
must remain as an assembly or if disassembled,
controlled to ensure that these component parts are
not intermixed with similar parts.
In the event that parts do become exchanged or you
suspect the air gap to be incorrect (Too much air gap
will result in loss of auxiliary power operation and
less than full spool shift; too little air will result in
erratic operation.), it may be checked and adjusted
using the procedure below.
All parts must be clean and properly assembled
before making these checks.
1.
With all parts assembled as shown in Figure 5-11.,
use a depth mike or other measuring instrument to
determine the distance from the end of the guide
tube to the exposed end of the plunger. Record this
dimension.
2.
Remove the plunger and poppet. With the poppet
removed, install the plunger and check the distance
from the end of the guide tube to the exposed end of
the plunger.
3.
Subtract the first dimension from the second dimen-
sion, this will be the amount of air gap.
4.
The correct air gap is 0.018"- 0.020" with 0.018" pre-
ferred. If the air gap is excessive, it may be reduced
by using a brass drift and hammer. Lightly tap the
end of the plunger with all parts assembled.
Recheck the air gap.
5.
If the air gap is less than recommended, replace the
nose cone assembly.
5.9
PRESSURE SETTING PROCEDURES
1.
Racine Proportional Valve Pressure Setting,
Machines Built Prior To Mid 1987 are shown in Fig-
ure 5-12. and Figure 5-13.
2.
Vickers Proportional Valve Pressure Setting,
Machines Built Prior To 1989 With Accessory Valve
are shown in Figure 5-14., Figure 5-15., Figure 5-16.,
and Figure 5-17.
3.
Solenoid Valve Pressure Settings Machines Built
Prior To May 1992 With Steer Wheel are shown in
Figure 5-18.
4.
Pressure And Flow Settings Machines Built Prior To
May 1992 With Steering Wheel are shown in Figure
5-19.
5.
Vickers Proportional Valve Pressure Setting,
Machines Built To Present are shown in Figure 5-20.,
Figure 5-21., Figure 5-22., and Figure 5-23.
6.
Vickers All Hydraulic Pressure Setting are shown in
Figure 5-24., Figure 5-25., Figure 5-26., and Figure
5-27.
7.
Solenoid Valve Pressure Settings Machines Built To
Present are shown in Figure 5-28.
8.
Solenoid Valve Pressure Settings 4 W/S are shown
in Figure 5-29.
9.
Extend - A - Reach Valve Pressure and Speed Set-
tings are shown in Figure 5-30.
Figure 5-11. Racine Proportional Air Gap Adjustment, Machines Built Prior to Mid 1987