# SDR ASAA2021091535946

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 15, 2021
- Submitted: September 16, 2021
- Operation: Air carrier
- Aircraft: [N423AS](https://openairdocs.org/aircraft/N423AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 35206
- Aircraft time: 30,359 hours, 9,752 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Control Valve
- Part number: 1605501
- Part serial: 882
- Condition: Inoperative
- Location: Apu
- Part time: 11,260 hours, 22,588 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/ASAA2021091535946

## Discrepancy

APU HAS ADDITIONAL REPORTS OF AUTO SHUTDOWN AFTER OIL COOLER REPLACEMENT FOR OIL OIL TEMP SD(#PRI 2)ETOPS SIGNIFICANT SYSTEM. GROUNDED - YES. REMOVED AND REPLACED APU TCV, REF B737-900 AMM 49-91-21. OP CHECK GOOD NO LEAKS NOTED. REMOVED AND REPLACED APU LUBE MODULE, REF AMM 49-91-11. OP CHECK GOOD, NO LEAKS NOTED.

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