Service Manual and
Axial Piston Motors Series 20
Repair Instructions
L1003443
• Rev BA • Jun 2014
3
Contents
General Information
Model Code
Recommended Tools and
Installation
Start-up procedure
System Maintenance
Troubleshooting
Disassembly and Assembly
Introduction ................................................................................................................................................................................ 2
Description .................................................................................................................................................................................. 2
Model Code ................................................................................................................................................................................. 4
Tools for Minor Repairs and Unit Maintenance ............................................................................................................. 5
Additional Tools for Complete Stripping of Units ......................................................................................................... 5
Measurement Instruments .................................................................................................................................................... 5
Troubleshooting, Gauge Installation and Information ............................................................................................... 6
Preconditions for Trouble-free Operation ....................................................................................................................... 7
Cleanliness ............................................................................................................................................................................ 7
Preconditions for trouble-free operation (continued) ................................................................................................ 8
Plumbing Installa tion (Variable Displacement Pump - Fixed Displacement Motor) ....................................... 9
System Circuit Description .................................................................................................................................................. 10
Inlet Filter ................................................................................................................................................................................... 11
Changing the oil ...................................................................................................................................................................... 11
Leak Test ..................................................................................................................................................................................... 11
Cleanliness ................................................................................................................................................................................. 11
Checking the oil level ............................................................................................................................................................ 11
Recommended oils................................................................................................................................................................. 11
Transmission Operates in one Direction Only .............................................................................................................. 12
System Response is sluggish .............................................................................................................................................. 12
System Operating hot ........................................................................................................................................................... 13
System will not operate in either direction ................................................................................................................... 13
Inspection Instructions ......................................................................................................................................................... 14
Checking the high pressure relief valve ................................................................................................................... 14
Preparation for Assembly .................................................................................................................................................... 15
Checking the shuttle valve ............................................................................................................................................ 15
Mounting block ................................................................................................................................................................. 15
Sectional View .......................................................................................................................................................................... 16
Axial piston fixed displacement motor ..................................................................................................................... 16
Exploded View ......................................................................................................................................................................... 17
Minor Repairs ............................................................................................................................................................................ 18
Changing the shaft seal (disassembly)...................................................................................................................... 18
Changing the shaft seal (assembly) ........................................................................................................................... 19
Changing the valve manifold assembly ...................................................................................................................20
Repair the manifold valve assembly .......................................................................................................................... 21
Installation Torque Values..............................................................................................................................................22
Changing the valve and bearing plate (disassembly) .........................................................................................23
Changing the valve and bearing plate (assembly) ............................................................................................... 24
Changing the cylinder block kit, the swash plate and the motor shaft (disassembly) ...........................25
Changing the cylinder block kit, the swash plate and the motor shaft (assembly) ................................. 27
