Page 10 Section 7
Troubleshooting
MSD SABER SERIES SHEARS
SPEED VALVE TROUBLESHOOTING GUIDE
There are two basic operating conditions of the speed valve that have a negative effect on shear performance
and require troubleshooting and adjustment or repair. The fi rst condition occurs when the speed valve does
not seem to shift into the regenerative or speed mode, resulting in the shear closing slowly. The second con-
dition occurs when the speed valve does not shift out of the speed mode at the appropriate time, resulting in
a loss of shear cutting force. These conditions are referred to below with corrective actions listed to remedy
the problem. For complete step-by-step instructions on adjusting the speed valve, please refer to page 4-37.
If the problem still exists after attempting these adjustments, please contact your Stanley LaBounty dealer or
the Stanley LaBounty Customer Service Department for further instructions.
The following tools and equipment are needed to properly troubleshoot and adjust the speed valve:
•
pressure gauges - two are recommended so that two test ports can be checked simultaneously
•
diagnostic test fi ttings and tools for installing the fi ttings
•
a set of open or box end wrenches (12mm - 19mm)
•
a set of Allen wrenches (4mm - 12 mm)
SYMPTOM
PROBABLE CAUSE
REMEDY
1. Shear does not shift consistently
into speed mode when closing
the jaw
2. Shear shifts into speed mode
when jaw has been fully opened,
but will not shift if jaws have only
been opened partially
3. Shear jaw continues to close
after the shear has shifted into
speed mode and the operator has
let go of the control
4. Shear properly shifts into speed
mode but seems to lack power
a. Pilot pressure setting is too high
a. Too much back pressure in the base
machine return line
a. The main valve spool in the speed valve
is not fully shifting out of speed mode
a. The main valve spool is not fully shifting
out of speed mode
i
. Adjust the pilot valve adjustment screw
counterclockwise in increments of 1/8 of
a turn (45˚) until corrected.
i. Minimize back pressure if possible by
using lines with larger diameters
ii. If (i.) is not possible or does not com-
pletely solve the problem, adjust the
main spool and then close adjustment
screw clockwise in increments of 1/8 of a
turn (45˚) until corrected.
i. Adjust the main spool adjustment
screw clockwise in increments of 1/8 of a
turn (45˚) until corrected.
i. Adjust the pilot valve adjustment screw
counterclockwise in increments of 1/8 of
a turn (45˚) until corrected
.
