JLG Lull 1044C-54 II Series Service Manual page 318

Frame Tilt and Oscillation
Disassembly, Oscillation Control Block
Check Valve
Pressure Reducing Cartridge
Solenoid Valve
Cleaning and Inspection, Oscillation Control Block
Assembly, Oscillation Control Block
Pressure Reducing Cartridge
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1. Note position of hydraulic fittings installed in block body then remove
fittings.
2. Remove pressure reducing cartridge (Item 15) and two (2) check valve
cartridges (Item 13).
3. Remove two (2) pilot pistons (Item 14).
4. Remove the one (1) SAE #2 plugs (Item 18), three (3) SAE #4 plugs
(Item 9), two (2) SAE #6 plug (Item 4), and SAE #10 plug (Item 10).
5. Orifice plug (Item 19) does not usually require removal. It will be
cleaned when the block body is flushed.
1. Remove O-rings and backup rings from pressure reducing valve
cartridge (Item 15), two (2) check valve cartridges (Item 13), counter
balance valve cartridge (Item 5), and PO Check Valve (Item 6). Clean
these components with solvent and dry with compressed air. Inspect
components for condition and cleanliness.
2. Thoroughly flush block body with solvent and dry with compressed air.
3. Clean remaining components (except solenoid coil) with solvent and
dry with compressed air.
4. Inspect orifice plugs (Items 17 and 19) for blockage and clean as
necessary.
1. If orifice plug (Item 19) was removed, install in block body so it is finger
tight. Tighten orifice plug 2–3 turns past finger tight.
2. Install two (2) SAE #6 plugs (Item 4). Torque plugs to 210–230 in-lbs.
3. Install one (1) SAE #2 plugs (Items 18). Torque plugs to 30–40 in-lbs.
4. Install three (3) SAE #4 plug (Item 9). Torque plug to 125–145 in-lbs.
5. Install SAE #10 plug (Item 10). Torque plug to 71–79 ft-lbs
(850–950 in-lbs).
6. Obtain new O-rings and backup rings for pressure reducing cartridge
(Item 15), two (2) check valve cartridges (Item 13), two (2) pilot pistons
(Item 14), counter balance valve cartridge (Item 5), and PO Check
Valve (Item 6). Lubricate all O-rings and backup rings with hydraulic oil
before installing on components.
7. Install large O-ring on pressure reducing valve cartridge (Item 15).
Install backup ring and O-ring on cartridge so backup ring is behind O-
ring.
8. Lubricate all O-rings and backup rings on pressure reducing cartridge
(Item 15). Install cartridge and torque to 270–300 in-lbs.
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