Lull 6K Service Manual User Manual
Page 200
Supply, Pressure, and Return Hydraulics
5-56
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
(Ref. Fig. 5-36) The following procedure describes disassembly of the
Combination Relief and Anti-Cavitation Check Assembly (CRA).
1. Loosen and remove four (4) each socket head capscrews, 33
lockwashers (Item 2), and bearing washers (Item 3).
2. Remove positioner housing (Item 4). Tag or mark housing; note
location of fitting port(s).
3. Remove square cut seal (Item 5) from housing (Item 6). Discard
square cut seal.
4. Loosen and remove relief assembly (Items 7 thru 21) from housing.
5. Loosen and remove acorn nut (Item 7), jam nut (Item 8), and
adjustable stem (Item 9) from adjustable relief cap (Item 10).
6. Loosen and remove adjustable relief cap from relief body (Item 18).
7. Remove relief poppet (Item 16), shims (Item 15), spring (Item 14), and
piston (Item 12) from adjustable relief cap.
8. Remove piston ring (Item 17) from relief poppet, O-ring (Item 13) from
piston, and O-ring (Item 11) from adjustable relief cap. Discard
O-rings.
9. Remove anti-cavitation poppet (Item 22) and spring (Item 23) from
housing.
10. Remove poppet retainer (Item 24) from housing. Then remove poppet
(Item 28) and check spring (Item 27).
11. Remove two (2) backup washers (Item 25) and O-ring (Item 26) from
poppet retainer.
12. Remove O-ring (Item 21) and backup washer (Item 20) from middle of
relief body.
13. Remove O-ring (Item 19) near head of relief body.
14. Discard all O-rings and backup washers.
15. Clean all remaining parts with solvent and dry with compressed air.
Inspect and replace any damaged parts.
Note: In the CRA assembly, only the O-rings, backup washers, and square cut
seal are replaceable. If other parts become damaged, it will be necessary
to replace the complete CRA assembly.
Note: In the positioner assembly, only the O-ring, hollow hex capscrews,
lockwashers, and bearing washers can be purchased separately. If other
parts become damaged, it will be necessary to replace the complete
positioner assembly.