HYDRAULIC SYSTEM-continued -714670053

TM 5-2420-244-34

Table 2-1. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

HYDRAULIC SYSTEM (CONT)

NOTE

The 0-5000 psi (0-345 bar) pressure gage must be calibrated. If not, performance of

backhoe/crane circuits and tool circuits will not be correct.

e. Connect 0-5000 psi (0-345 bar) pressure gage to test port (5) on inlet section (6)

of control valve (7).

Start and run engine at idle speed of 2000 rpm.

g. Place lock control lever (8) in up position and hold for 15 seconds; then place

lever in neutral for 30 seconds.

h. Repeat steps f and g until hydraulic oil cooler turns on. Oil will then be at operating

temperature of 120F (49C).

Keep engine running at 2000 rpm.

Place lock control lever (8) in up position and read 0-5000 psi (0-345 bar) pressure

gage. Reading must be 2450 psi (169 bar).

If pressure reading is not 2450 psi (169 bar), hold adjusting screw (9)

and loosen lock nut (10) on relief valve (11). Turn adjusting screw (9)

to right to increase pressure, or to left to decrease pressure. Hold

adjusting screw (9), tighten lock nut (10), and check 0-5000 psi (0-

345 bar) pressure gage for reading of 2450 psi (169 bar). Repeat as

necessary.

If 2450 psi (169 bar) cannot be attained, go to step 3.