04/15/20
Message Overview:
| DDG Reference: | None |
| Pilot Action (QRH): | ABNORM 10-7 |
| System Description: | 29-30-00 |
| Schematic Diagram: | 29-12-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 29-00-04 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
DAU 2 is reporting both the EDP 2A and ACMP 2B pressure switches and system pressure transducer are less than 1800 psi with engines running or aircraft in a weight-off-wheels condition.
Possible Causes:
- Low Quantity
- Hydraulic Fluid Filter Elements
- Hydraulic System Pressure Relief-Valve (Filter Manifold)
- Pressure Transducer
- Pump
- Data Acquisition Unit 2 (DAU 2)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- 700T-0022 - Hydraulic System - Fluid Transfer
- 700T-0040 - Unapproved Hydraulic Fluid
- 700T-0124 - Hydraulic System Filters: Possible Incorrect Filters Installed in Hydraulic Systems 1, 2, and 3
Forum Articles/Infoservice/Newsletter: None
NOTES:
If there are multiple CAS messages, consider troubleshooting sequencing.
When replacing the pressure filters, a hydraulic lock has been known to prevent new filter installation. A "B" nut next to the filter manifold may need to be loosened or removed to bleed off pressure and allow the installation of the filter.
Quick Links:
| Quantity Check of the Hydraulic Reservoir Fluid | AMM 12-12-00-610-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of Data Acquisition Units (DAU) | AMM 31-42-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of Data Acquisition Units (DAU) | AMM 31-42-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of No. 1 and No. 2 Hydraulic System Filter Manifold | AMM 29-12-09-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of No. 1 and No. 2 Hydraulic System Filter Manifold | AMM 29-12-09-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of No. 1 and No. 2 Return Filter Element | AMM 29-12-17-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of No. 1 and No. 2 Return Filter Element | AMM 29-12-17-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of No. 1 and No. 2 Press Filter Element | AMM 29-12-13-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of No. 1 and No. 2 Press Filter Element | AMM 29-12-13-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of EDP | AMM 29-12-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of EDP | AMM 29-12-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of No. 1 and No. 2 ACMP | AMM 29-12-05-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of No. 1 and No. 2 ACMP | AMM 29-12-05-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of Hydraulic Temperature Transducers | AMM 29-33-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of Hydraulic Temperature Transducers | AMM 29-33-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair | SPM 20-12-10 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Carry out a quantity check of the hydraulic system.
- If system low quantity found. Service system. Check system for leaks. Do close out.
- If quantity is good, continue with next step.
- Inspect system filter DPI(s).
- If DPI tripped. Investigate clogged filter. Do close out.
- If not tripped, continue with next step.
- Run system 2 AC Motor pump. Check system pressure.
- If system pressurizes, replace engine pump. Do close out.
- If fault still present, continue with next step.
- Run #2 Engine. Check system pressure.
- If system pressurizes. Investigate why AC motor pump is not working. Do close out.
- If fault is still present, continue with next step.
- Perform wiring check between the no. 2 filter manifold transducer (MT143), DAU No. 2, and SPDA 2. Ensure 28 VDC input from SPDA 2 to transducer.
- If wiring repairs made. Confirm fault is no longer present. Do close out.
- If wiring checks good, continue with next step.
- If no voltage Swap SPDA. If failure follows SPDA. Replace failed unit. Do close out.
- If fault is still present, continue with next step.
- Swap the no. 2 system manifold transducer (MT143) with system 1 system transducer MT140.
- If low pressure indication swapped to system #2 replace failed transducer. Do close out.
- If fault remained on #2 system, continue with next step.
- Swap DAU no 2 with DAU 1.
- If fault is no longer present. Replace failed DAU. Do close out.
- If fault remains, continue with next step.
- Replace #2 Hydraulic system manifold filter.
- If failure is no longer present, investigate why filter was causing a low pressure condition. Do close out.
- If fault is still present, continue with next step.
- Swap filter manifolds with system #1.
- If fault switched to #1 system replace failed filter manifold. Do close out.
- If fault is still present, continue with next step.
- Consider a bypassing hydraulic system component. Such as a reservoir may be bypassing from the high to low pressure side.
- Do close out.