HYDRAULIC SYSTEM-continued -714670056

TM 5-2420-224-34

Table 2-1. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

HYDRAULIC SYSTEM (CONT)

b. Connect hydraulic hose (1) to input side of flow meter.

c. Connect hose (3) to outlet side of flow meter. Place other end of hose

(3) into hydraulic tank (4).

NOTE

Make sure load valve on flow meter is completely open.

Make sure engine idle speed is maintained at 2000 rpm during entire test. Failure

to do so may result in incorrect readings and improper evaluation of hydraulic pump

flow rate.

d. Start and run engine at idle speed of 2000 rpm.

NOTE

Monitor oil temperature during entire test. Do not allow oil temperature to exceed 140 F

(60 `C). Failure to do so may result in incorrect readings and improper evaluation of

hydraulic pump flow rate.

e. Cycle oil until oil is at operating temperature of 120 F (49C).

f . Record flow rate.

g. Close load valve until 1000 psi (69 bar) is noted on flow meter. Record

flow rate.

h. Open load valve until 0 psi (0 bar) is noted on flow meter.

Close load valve until 1500 psi (103.4 bar) is noted on flow meter.

Record flow rate.

Open load valve until 0 psi (0 bar) is noted on flow meter.

k. Close load valve until 2000 psi (138 bar) is noted on flow meter.

Record flow rate.

Open load valve until 0 psi (0 bar) is noted on flow meter.

m. Close load valve until 2450 psi (169 bar) is noted on flow meter.

Record flow rate.

n. Shut off engine.

Divide flow rate recorded in step m by flow rate recorded in step f.

This is the percentage of hydraulic pump efficiency.

If hydraulic pump efficiency is less than 75 percent, replace

front or rear hydraulic pump (TM 5-2420-224-20).

2-21