TM 9-2320-269-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
HYDRAULIC SYSTEM - CONTINUED
DERRICK WILL NOT LOWER
Step 1. Test derrick controls.
a. Engage power takeoff, start engine, and operate console controls and operator's
controls (TM 9-2320-269-10).
b. If one set of controls works properly but not the other set, shut off engine, disengage
power takeoff, and notify Direct Support Maintenance.
c.
Shut off engine, and disengage power takeoff (TM 9-2320-269-10).
Step 2. Test elevation cylinder (2) holding valve.
a. Loosen jamnut (4), and screw in adjusting screw (5), counting number of times turned,
using 9116-inch box-end wrench and3/16-inch socket key until derrick (1) lowers.
b. If derrick (1) does not move, unscrew adjusting screw (5) the same number of times
turned in, tighten jamnut (4) using 9116-inch box-end wrench and 3/16-inch socket
key, and notify Direct Support Maintenance.
TA228645
2-139
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