Service Manual User guide
Table Of Contents
- 10709790_B_644B,6K,844C,8K,1044C,10K_Lull_Service_Mnl
- Quick Reference
- Revision Record
- Table Of Contents
- List Of Figures
- List Of Tables
- Section 1 Safety
- Section 2 Identification & Specifications
- Section 3 General Maintenance
- Section 4 Reference Diagrams
- Section 5 Supply, Pressure & Return Hydraulics
- Section 6 Boom & Transfer
- Section 7 Frame Tilt & Oscillation
- Section 8 Transmission
- Section 9 Brakes
- Section 10 Outriggers

Supply, Pressure, and Return Hydraulics
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
5-91
(Ref. Fig. 5-58) The hydraulic ports on models with control manifold
hydraulics are:
• Pump 1 – Used for reading pressure of the hydraulic pump #1.
Pressure limit is 2650 psi.
• Pump 2 – Used for reading pressure of the hydraulic pump #2.
Pressure limit is 2800 psi.
• Carr. Tilt (Base End) – Used for reading pressure for the base end of
the carriage tilt cylinder. Pressure limit is 2800 psi.
• Carr. Tilt (Rod End) – Used for reading pressure for the rod end of the
carriage tilt cylinder. Pressure limit is 2800 psi.
• Brakes – Used for reading pressure of the brake circuit and is used to
indicate when pressure is eliminated from the system prior to discon-
necting hydraulic hoses. Pressure limit is 330 psi.
• Steering – Used for reading pressure of the steering circuit. Pressure
limit is 2200 psi.
• Pilot – Used for reading pressure of the joystick circuit. Pressure limit
is 450 psi.
• Accum. – Used for reading of pressure in the accumulator charging
circuit. Pre-charge pressure is 400 psi. The low pressure limit is 1200
psi and the high pressure limit is 1600 psi.
CAUTION: To ensure that system is kept free of dirt and contamination,
always cap all ports when not in use.
Models with Mid-Inlet Hydraulics
6K-37 (S/N 318–)
6K-42 (S/N 120–)
8K-42 (S/N 221–)
10K-42 (S/N 107–)
10K-54 (S/N 104–)
644B-37 (S/N 591, 667–)
644B-42 (S/N 208–)
844C-42 (S/N 622–)
1044C-42 (S/N 117–)
1044C-54 (S/N 155–)
Fig. 5-59: Hydraulic Diagnostic Ports - Models with Mid-Inlet Hydraulics
(Ref. Fig. 5-59) The hydraulic ports on models with mid-inlet hydraulics
are:
• Pump 1 – Used for reading pressure of the hydraulic pump #1.
Pressure limit is 2650 psi.
• Pump 2 – Used for reading pressure of the hydraulic pump #2.
Pressure limit is 2800 psi.
• Rear Osc. Lock (G1) – Used for reading output pressure of the sole-
noid valve SV1. It is useful when diagnosing service malfunctions in
the rear axle stabilizer circuit.
• Rear Osc. Lock (G2) – Used for reading pressure in the rear oscilla-
tion lock circuit.
PUMP 1 PUMP 2 BRAKES STEERING PILOT ACCUM.
REAR OSC.
LOCK (G1)
REAR OSC.
LOCK (G2)
K1168