Rap 2.28 Knife Latch Cylinder - Challenge CMT-130TC Service Manual

RAP 2.28 Knife Latch Cylinder

Output 3
The knife latch prevents the knife assembly from
moving down whenever the hydraulic motor is
not running. The latch is located on the table at
the rear of the machine (Figure 2-40). A spring-
extend air cylinder drives latch. The latch is en-
gaged (cylinder extended) whenever the hydrau-
lic motor is off.
Fault Indicator

Knife assembly drifts down over time.

"Knife Latch did not pull
in!" message is displayed.

"Knife Latch OUT when it
should be IN!" message is dis-
played.
Initial Actions
Perform RAP 2.20 Pneumatic Pressure.
Perform ADJ 4.18 Knife Latch.
Check for air leaks and disconnected or pinched
hoses.
Check for loose or damaged wire 71 at the elec-
trical panel.
Check that the cable connector on valve #8 is
connected properly.
Procedure
1. Switch the main air ON and main power ON.
2. Press the green start button to initialize the
trimmer. This will raise the cutting mecha-
nism off of the knife latch if necessary.
3. Open the rear door and move the knife latch
cylinder in and out by hand. Does the cylin-
der move freely?
2. Status Indicator RAPs
Y N
Did the knife mechanism drift down onto the
latch?
Y N
Perform ADJ 4.18 Knife Latch and re-
place knife latch cylinder if faulty (PL 5.5
Main Assembly 59000 (5/14))
Go to ADJ 4.14 Counterbalance Valve.
4. Manually activate valve #8 by pressing the
actuator button on the valve (Figure 2-41).
Does the valve actuate and the latch cylin-
der retract?
Y N
Disconnect power and replace valve #8 (PL
5.22 Pneu. Manifold Asm. 59012-1).
5. Electrically activate valve #8 by shorting wire
71 to 74. Does the valve actuate and the
latch cylinder retract?
Y N
Disconnect power and replace valve #8 (PL
5.22 Pneu. Manifold Asm. 59012-1).
6. Disconnect power and replace the main
PWB (REP 4.23 Main PWB Replacement).
MAY 2019
2-36
Figure 2-40. Knife Latch
Figure 2-41. Pneumatic Valve #8
CMT-130TC Book Trimmer