TM 5-5420-280-23&P
0010 00
Hydraulic System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. HYDRAULIC SYSTEM WILL NOT OPERATE USING LAUNCH POWER UNIT (LPU) (CONTD)
Step 7. Check sight gauges to see if in red zone for clogged oil pre-filter or clogged oil filter on
a. If gauges are in red zone, replace clogged oil pre-filter. Refer to WP 0080 00.
b. If gauges are in red zone, replace clogged oil filter on control valve manifold. Refer to
Step 8. Using oil pressure test kit, check for lower settings or damaged 016 oil pressure regulator
valve on top of control valve manifold.
a. Engage KY1 control valve and set pressure to 2190 psi (220 bar) on oil pressure regulator
b. Replace 016 oil pressure regulator valve if damaged. Refer to WP 0076 00.
END OF TESTING
2. HYDRAULIC SYSTEM WILL NOT OPERATE USING CBT
Step 1. Check that engine is operating and PTO is engaging on CBT.
Start engine and engage PTO on CBT. Refer to TM 5-5420-280-10.
Step 2. Check that hydraulic hose quick-disconnectors are connected to CBT.
Connect hydraulic hose quick-disconnectors to CBT. Refer to TM 5-5420-280-10.
Step 3. Check for low oil level in CBT reservoir.
Fill CBT reservoir to proper oil level. Refer to TM 5-5420-280-10.
NOTE
KY1 is the main pressure hydraulic control valve and it must
operate with all other control valves to perform an operation.
If lights are on and system will not operate, replace solenoids or
Step 4. Check for loose electrical connector (WP 0008 00) or damaged KY1 hydraulic control valve
a. Manually engage KY1 hydraulic control valve by pressing down on button on top of
solenoid, if system operates. (Check Electrical System Troubleshooting WP 0008 00).
b. Tighten or replace electrical connector on KY1 control valve solenoid. Refer to
c. Replace damaged KY1 hydraulic control valve. Refer to WP 0075 00.
Step 5. Check sight gauges to see if in red zone for clogged oil pre-filter or clogged oil filter on
a. If gauges are in red zone, replace clogged oil pre-filter. Refer to WP 0080 00.
b. If gauges are in red zone, replace clogged oil filter on control valve manifold . Refer to WP
Step 6. Using oil pressure test kit, check for lower pressure setting or damage to 016 oil pressure
regulator valve on control valve manifold.
a. Engage KY1 control valve and set pressure to 2190 psi (220 bar) on oil pressure
b. Replace 016 oil pressure regulator valve if damaged. Refer to WP 0074 00.
END OF TESTING
