Description

Liebherr R900C, R904C Litronic Wheel Excavator Manual

Excavator Model Applicable Model:
R 900 C EDC Litronic Valid from serial number 43272 (Type 1076)
R 900 C Litronic Valid from serial number 15329(Type 971 Std / 981 HDS / 982 HDSL)
R 904 C Litronic Valid from serial number 12305 (Type 983 HDSL 2250 / 984 Std 2000 / 985 HDSL 2000 / 993 EW / 1017 Std 2000 / 1018 SLC 2250)
Language: English
Publication: 10069965 & 10301850
Format: PDF
November 2011

Liebherr R900C, R904C Litronic Wheel Excavator Service Manual – 1054 Pages & 1377 Pages
Operation and Maintenance (Owners) Manual  – 230 Pages

Table of Content of the Service Manual:

• 1 General information
• 2 Tools
• 3 Technical data / Maintenance guidelines
• 4 Engine
• 5 Coupling / Splitterbox
• 6 Hydraulic system
• 7 Hydraulic components
• 8 Electrical system
• 9 Swing gear
• 10 Swing ring
• 11 Travel gear
• 12 Track components
• 16 Options
• 17 Cab / Heater / Air conditioning system
• 18 Central lubrication

This manual contains technical data, design and functional descriptions, as well as service and set up instructions. The documents include numbers of drawings, functional diagrams, as well as detailed views of units and assemblies of LIEBHERR hydraulic excavators.

This manual has been created in order to assist the customer support services, but does of course replace neither proper technical training and qualification of the user nor participation in LIEBHERR operator training courses.

Manual Extract – Pressure valves and feed valves 511 (2-stage for AHS 11)

The servo-controlled pressure relief valve 511 of the consumer connection is designed as a cartridge and is screwed directly into control valve block 100. The valve features a hydraulic pressure cut-in stage and can therefore be used for two different pressure ranges. It restricts the pressure between pump, control valve block and tool (stage 1 – primary function – hammer operation) or between tools and control valve block with closed control piston (stage 2 – secondary function – adjusting cylinder protection).

If the pressure in a circuit of the equipment increases to an excessive degree, the weakest point, e.g.
threaded unions or hydraulic hoses would sustain damage.

In order that this may be avoided, a simulated weak point, in other words a predetermined break point, is incorporated. The increasing system pressure in the hydraulic system is thus directed to a hydraulic device. This appliance is known as a pressure relief valve. It limits the maximum pressure in the consumer and its connections to the set value.