Troubleshooting hydraulic leaks and pressure faults
How to find, classify and fix external and internal leaks, low and fluctuating pressure, overheats, contamination, indication and accumulator faults, and decide on dispatch
What you will be able to do
- ✓ Apply a structured fault-finding method to hydraulic symptoms, reading pressure, quantity and temperature indications correctly and pressurising the system safely.
- ✓ Classify external leaks from static and dynamic seals against the manual's allowable rates, and trace them to their source, using the official findings on Boeing 787-8 9V-OFG.
- ✓ Diagnose low and fluctuating pressure, including pump wear by case drain flow, reservoir pressurisation, priority valve and relief valve faults.
- ✓ Measure internal leakage by isolating sections of a system, and trace an overheat to its source.
- ✓ Take and interpret fluid samples after contamination events, including particle counts, water and wrong-fluid events.
- ✓ Separate quantity indication faults and accumulator pre-charge faults from real losses, prove a repair, and make an MEL dispatch decision.
Course content
Session 1 · A method for hydraulic fault finding
1.1
- From symptom to cause · free preview
- Reading the indications
- Pressurising safely to find a fault
- Worked example: turning a quantity trend into a leak rate
Session 2 · External leaks: finding and classifying them
1.2
- Static and dynamic seals
- Allowable leak rates in the maintenance manual
- Tracing a leak to its source
- From the investigation file: the reverser hose on 9V-OFG
Session 3 · Low and fluctuating pressure: the supply side
1.3
- What low pressure is telling you
- Case drain flow: the pump's health check
- Reservoir pressurisation and priority valves
- Worked example: case drain flow against the limit
Session 4 · Internal leakage and overheating
1.4
- Internal leakage: the leak you cannot see
- Measuring internal leakage by isolating sections
- Overheat: finding where the heat comes from
- Worked example: finding internal leakage by isolating sections
Session 5 · Contamination events
1.5
- When to take a sample, and how
- Particles, water and what the numbers mean
- Mixed fluids and the wrong-fluid event
- Worked example: deciding on a fluid sample result
Session 6 · Indications, accumulators and the return to service
1.6
- Quantity indication faults
- Accumulator pre-charge faults
- After-repair checks and the dispatch question
- Worked example: a dispatch decision with one system low
Who this course is for
Course content © Aerospace Garage Limited. All rights reserved.