# SDR ASAA2021052334876

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 23, 2021
- Submitted: May 24, 2021
- Operation: Air carrier
- Aircraft: [N592AS](https://openairdocs.org/aircraft/N592AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35190
- Aircraft time: 48,248 hours, 14,374 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Oil Cooler
- Part number: 1605642
- Part serial: 3782
- Condition: Faulted
- Location: Apu
- Part time: 13,166 hours, 19,729 cycles
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021052334876

## Discrepancy

APU OIL MONITORING DATA SHOWS OIL CONSUMPTION TO BE TRENDING HIGHER THAN EXPECTED. GROUNDED - YES. ACCOMPLISHED APU OIL CONSUMPTION FAULT ISOLATION PER B737-800 FIM 49-95 TASK 801. FOUND SIGNS OF OIL COOLER LEAKING. REMOVED OIL COOLER AND FOUND INBOARD AIR FINS SATURATED WITH OIL. REF B737-800 AMM 49-91-41-200-801 FOR OIL COOLER INSPECTION. INSTALLED NEW OIL COOLER, LEAK CHECK GOOD. REF AMM 49-91-41. RAN APU AGAIN, NO OTHER OIL LEAKS FOUND.

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