Installation-CONT. - TM-10-3930-673-20-20561

TM 10-3930-673-20-2

c. Main Relief Valve Adjustment.

NOTE

There are four relief valves on main

control valve. Adjustment of main control

valve is limited to adjustment of relief

valves.

(1)

Connect pressure gage to port.

(a)

Remove main relief valve plug (1) from

port (2).

(b)

Connect 0 - 5,000 psi (0 - 34475 kPa)

pressure gage to port (2).

(c)

Start engine (TM 10-3930-673-10).

NOTE

TR01027

Engine may be operated at idle or full

throttle when performing tests/

adjustments.

(d)

Operate boom hoist, lower, extend, or retract function until cylinder bottoms out and hydraulic oil is passing

over relief valve. Continue to hold hydraulic lever in that position so oil passes over relief valve during relief

valve adjustment.

NOTE

Pressure must read between 3,000 - 3,100 psi (20685 - 21374.5 kPa).

(2)

Read relief valve pressure on gage. If relief valve pressure is not within specifications, adjust as follows:

(a)

Remove acorn nut (3) covering slotted head adjusting screw.

(b)

Hold adjusting screw and loosen/back off jam nut (4).

(c)

To increase relief pressure, turn adjusting screw clockwise (in). To decrease pressure, turn adjusting screw

counterclockwise (out).

(d)

When desired relief pressure shows on gage, hold adjusting screw and tighten jam nut (4). Install acorn nut

(3).

(e)

Shut off engine (TM 10-3930-673-10).

(3)

Remove pressure gage.

Remove pressure gage from port (2).

(4)

Install main relief valve plug (1).

Install main relief valve plug (1) in port (2).

(5)

Replace transmission cover (Para 16-5).

18-27