Lull 6K Service Manual - Manual (Page 198)

Supply, Pressure, and Return Hydraulics
5-54 Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
4. Remove O-ring (Item 5) and backup washer (Item 4) from middle of
load check plug.
5. Remove remaining O-ring (Item 3) near head of load check plug.
6. Discard all O-rings and backup washers.
7. Clean remaining parts with solvent and dry with compressed air.
Inspect and replace any damaged parts.
Note: Only the O-rings and backup washers of the load check valve are
replaceable. If other parts become damaged, it will be necessary to
purchase a new load check valve.
Assembly, Load Check Assembly
(Ref. Fig. 5-35) The following steps are required to reassemble the load
check assembly:
1. Obtain a load check seal kit. Lubricate O-rings and backup washer with
hydraulic oil.
2. Install large O-ring (Item 3) first. Install backup washer (Item 4) and
O-ring (Item 5) near middle of load check plug. Then install backup
washers (Items 6 and 8) and O-ring (Item 7) making sure that the
O-ring is between the two backup washers.
3. Install spring and poppet in end of load check valve.
4. Lubricate load check valve with hydraulic oil and install it on housing.
Torque to 20 ft-lbs.