Maintenance and repair 33/44
RE25802-XC-B/07.19, DB...5X/...XC
Bosch Rexroth AG
10.4 Repair
WARNING
Explosion hazard due to improper repair!
In case of improper repair, the explosion protection no longer applies in subsequent
operation!
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For repair works, the valve may only be disassembled to the extent described
in these operating instructions.
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Defective parts may only be replaced by new, interchangeable components
in original equipment quality.
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The sealing between main and pilot stage may not be removed.
10.5 Rectifying external leakage
External leakage at the valve connection surface can be rectified on site.
With other leakage, the valve must be replaced by a new valve (see chapter 14
"Troubleshooting").
Only the seals indicated in chapter 10.6 "Spare parts" may be used. Using other
seals is not admissible!
10.5.1 Rectifying leakage at the valve connection surface
1.
Switch off the hydraulic power unit, let the pressure decrease and relieve any
pressure accumulators, if applicable.
2.
Remove the safety valve, see chapter 11 "Disassembly and removal".
3.
Check whether the recesses for the seal rings at the valve connection surface are
clean and intact.
4.
Dry the valve connection surface and the valve contact surface using suitable
cleaning materials.
5.
Assemble the new seals, observe the suitability of the seal material for the
hydraulic fluid used.
6.
Assemble the valve, see chapter 7 "Assembly".
If hydraulic fluid continues to leak after re-installation, the valve is defective. Send
the valve back to the manufacturer for replacement.
10.5.2 Rectifying leakage at port X or Y
1.
Depressurize the system. Verify the depressurized state using a pressure gauge
so that the ports can be opened in a risk-free manner.
2.
Remove the plug screw using a suitable tool (internal hexagon, wrench size 6).
3.
Check whether the surface for the seal ring is clean and intact.
4.
Screw the plug screw in again and tighten it using a torque power screwdriver
and a tightening torque of 30 ± 3 Nm. Make sure that the seal is available and
correctly seated.
