COUNTERBALANCE VALVES -706880641

TM 5-4210-233-14&P-1

4-204. COUNTERBALANCE VALVES

This task covers:

a. Replacement of Valve Cartridge

d. Follow-on Maintenance

b. Removal of Valve Block

c. Installation of Valve Block

TOOLS REQUIRED

EQUIPMENT CONDITION

Tool Kit, General Mechanics, Automotive

Ladder Fully Retracted and Elevated (see para 2-14 .)

(Appendix B, Section III, Item 1)

Main Engine Shutdown (see para 2-12 .)

APU Shutdown (see para 2-16 .)

MATERIALS/PARTS REQUIRED

Emergency hydraulic system deactivated

Grease, Automotive (Item 1, Appendix E

Tags (Item 32, Appendix E)

Batteries Disconnected (see para 4-114 .)

Hydraulic Oil (Item 28, Appendix E)

Caps, Shipping and Sealing (Item 39, Appendix E)

O-ring (Figure 188, Appendix F)

a. Replacement of Valve Cartridge.

(1) With engine off, actuate three ladder control

levers in each direction to relieve pressure in

hydraulic system.

CAUTION

Do not loosen or tighten hex fitting on end of valve

cartridge. Do not attempt to adjust or change the

setting of the valve cartridge.

(2) Remove valve cartridge (1) by unscrewing large

hex nut (2) closest to valve block.

(3) Install new valve cartridge (1) and tighten large hex

nut (2) closest to valve block only.

b. Removal of Valve Block.

(1) Tag and disconnect two hydraulic hoses (3) and

two tubes (4). Cap hose and tube ends to prevent

entry of dirt.

(2) Remove two capscrews (5) and remove valve

block (6) from end of cylinder. Remove and discard

two O-rings (7) between valve block and cylinder.

4-512