Boom Hoist Relief Valve Adjustment-CONT.

TM 10-3930-673-20-2

(c)

Operate boom hoist function until boom is fully raised. Continue to hold boom control lever in position so

hydraulic oil passes over relief valve.

(d)

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

counterclockwise (out).

(e)

When desired relief pressure shows on gage, release boom hoist lever.

(f)

Hold adjusting screw in position and tighten jam nut (8).

(g)

Install acorn nut (7).

(4)

Adjust main relief valve pressure to between 3,000 - 3,100 psi (20685 - 21374.5 kPa).

(a)

Operate boom extend, retract, hoist or lower function until 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.

(b)

Turn adjusting screw counterclockwise (out) until pressure on gage reads between 3,000 - 3,100 psi (20685 -

21374.5 kPa).

(c)

Release hydraulic function lever.

(d)

Hold adjusting screw in position and tighten jam nut (4).

(e)

Install acorn nut (3).

(f)

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

(5)

Remove pressure gage.

Remove pressure gage from main relief valve plug port (2).

(6)

Install main relief valve plug (2).

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

(7)

Replace transmission cover (Para 16-5).

18-31