Stanley MSD 1000 Safety, Operation & Maintenance Manual page 84

MSD SABER SERIES SHEARS
SPEED VALVE ADJUSTMENT
continued
10. Have the excavator operator cycle the shear to
the fully closed position and set the pilot valve to
its maximum setting. Turn the pilot valve adjust-
ment screw clockwise until the cylinder just fails
to shift out of speed mode. You may need to open
and close the shear multiple times to reach the
pilot valve maximum setting. The pressure gauge
attached to the MAZ port should read approximately
400 psi or higher when in speed mode.
NOTICE
DO NOT make adjustments to the speed valve while
the cylinder is extending.
11. Have the excavator operator cycle the shear to
the fully closed position then set the pilot valve to
its minimum setting. Turn the pilot valve adjustment
screw counter-clockwise until the cylinder just fails
to shift into speed mode. You may need to open
and close the shear multiple times to reach the
pilot valve minimum setting. The pressure gauge
attached to the MBS port should read approximately
full system pressure when not in speed mode. Pay
careful attention to the number of turns required to
reach this setting.
12. Have the excavator operator return the shear to
the fully open position a second time. Re-adjust the
pilot valve adjustment screw to the fi nal setting by
turning the adjustment screw clockwise 1/2 of the
number of turns required to reach the minimum set-
ting and tighten the lock nut. This brings the valve
to its median setting, which is optimum for most
operating conditions.
13. Test the adjustments by cycling the shear to the
closed position six times normally and six times
with the shear stalled in the closed position. Moni-
tor the gauge attached to the MAZ carefully. During
normal cycling, the gauge should read 400psi (26
bar) or higher. When stalling the shear, gauge pres-
sure should drop to zero.
Page 46 Section 5 Maintenance
14. Verify the shift pressure. Have the excavator
operator cycle the shear to the fully closed position
and carefully monitor the pressure gauge attached
to the MAZ test port. Note the pressure reading
immediately before the shear stalls. This pressure is
the shift pressure required to shift the speed valve
out of speed mode. Shift pressure should be 3600 –
3700 PSI. (248 - 255 BAR).
15. Turn the excavator off and release all hydraulic
pressure to the shear by working the excavator
controls in all directions. Be certain to relieve the
air pressure in the excavator reservoir. Refer to the
excavator operator's manual for proper excavator
hydraulic pressure relief procedures. Detach the
digital pressure gauge(s) and pressure line(s) from
the MBS and /or MAZ test fi tting(s). Slowly remove
the test fi tting(s) from the test port(s) as in step 3
of this procedure and replace the MBS and/or MAZ
port plug(s).
16. Restart the excavator. Check for leaks by using a
piece of cardboard or other rigid material. Repair all
leaks before using the shear. Re-apply the correct
torque to all speed valve fasteners including split
fl anges if found leaking. Use the table on page 8-26
for correct torque values.
17. Speed valve troubleshooting procedures can be
found on page 7-10 in the Troubleshooting section in
the back of this manual.