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Bosch Rexroth AG
M-...S...SO711/712 | RE 22340-B1/11.12
Troubleshooting
14 Troubleshooting
14.1 How to proceed with troubleshooting:
f
Always work systematically and targeted, even when under time pressure.
Random and imprudent disassembly and readjustment of settings might result
in the inability to restore the original cause of fault.
f
First get a general idea of how your directional seat valve works in conjunction
with the overall system.
f
Try to establish whether the directional seat valve was working properly in
conjunction with the overall system before the fault first occurred.
f
Try to determine any changes of the overall system in which the directional
seat valve is integrated, e.g.:
– Changes in the application conditions or the area of application?
–
Were there any changes (e.g. retrofitting) or repair works at the overall sys
-
tem (machine/system, electrics, control) or at the directional seat valve? If so:
What were they?
– Was the directional seat valve or machine used as intended?
– How did the fault become apparent?
f
Try to get a clear idea of the cause of fault.
Fault table
The directional seat valve is usually not sensitive to faults if the prescribed ap-
plication conditions and hydraulic fluid quality are complied with.
Table 11: Fault table
Fault
Possible causes
Remedy
Directional seat valve does not switch
Missing pilot pressure
Check and/or reapply pressure at the ports.
Spool is jammed due to contamination
Loosen the jamming by switching the valve
several times. In case the actuation is stiff,
disassemble the directional seat vale and
replace it by a new directional seat valve.
External leak
Seals at valve connection surface damaged Remove the directional seat valve and
replace the seals, see 10 "Maintenance
and repair".
Other leakage
Replace the directional seat valve.
Following faults due to contamination, it is - in addition to the repair - essential to
check the hydraulic fluid quality and improve it, if necessary, by suitable measures
such as flushing or the additional installation of filters.
If you could not remedy the occurred error, please contact one of the address-
es specified in section 15.2
"List of addresses".
