Lull 6K Service Manual - Manual (Page 539)

Frame Tilt and Oscillation
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 7-37
(Ref. Fig. 7-22) Follow the guidelines for cleanliness as stated in Section 5
of this manual. The following procedures are for the disassembly, cleaning,
and assembly of the oscillation control block.
Disassembly, Oscillation Control Block
Check Valve 1. Note position of hydraulic fittings (Items 4–6) installed in block body
(Item 17) then remove fittings. Remove the check valve (Item 3) from
the SYS port. The orifice plug (Item 7) is used on models with control
manifold hydraulics and does not usually require removal.
Note: Elbow (Item 4) is used on models with control manifold hydraulics only.
Models with mid-inlet hydraulics use a hydraulic hose which connects
directly to the check valve (Item 3).
Pressure Reducing Cartridge 2. Remove pressure reducing cartridge (Item 28) and two (2) check valve
cartridges (Item 21).
3. Remove two (2) pilot pistons (Item 25).
Solenoid Valve 4. For models with control manifold hydraulics, remove the nut (Item 16)
and coil (Item 15) from the solenoid valve (Item 14). Remove the
solenoid valve.
5. Remove the two (2) SAE #6 plugs (Item 1), two (2) SAE #2 plugs
(Items 8 and 34), SAE #4 plug (Item 19), and SAE #10 plug (Item 20).
Note: Models with mid-inlet hydraulics do not have the SAE #2 plug (Item 8).
6. Orifice plug (Item 2) does not usually require removal. It will be cleaned
when the block body is flushed.
Cleaning and Inspection, Oscillation Control Block
1. Remove O-rings and backup rings from pressure reducing valve
cartridge (Item 28), two (2) check valve cartridges (Item 21), and
solenoid valve (Item 14). Clean these components with solvent and dry
with compressed air. Inspect components for condition and
cleanliness.
2. Thoroughly flush block body (Item 17) 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 2 and 7) for blockage and clean as
necessary.
Assembly, Oscillation Control Block
1. If orifice plug (Item 2) was removed, install in block body (Item 17) so it
is finger tight. Tighten orifice plug 2–3 turns past finger tight.
2. Install two (2) SAE #6 plugs (Item 1). Torque plugs to 210–230 in-lbs.