# SDR AALA202502135205

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 11, 2025
- Submitted: February 14, 2025
- Operation: Air carrier
- Aircraft: [N823NN](https://openairdocs.org/aircraft/N823NN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 29560
- Aircraft time: 44,571 hours, 18,877 cycles
- System (JASC): [3240 · Landing Gear Brake System](https://openairdocs.org/jasc/3240)
- Part: Metering Valve
- Part number: 71404
- Part serial: 10634A
- Condition: Vibration
- Location: Zone 700
- Stage of operation: TX
- How discovered: O
- Nature of condition: S
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202502135205

## Discrepancy

AIRCRAFT WAS GROUNDED: BRAKE APPLICATION WHILE TAXING CAUSED LOUD SQUEALING NOISE AND VIBRATION. REMOVED AND REPLACED LEFT HAND BRAKE METERING VALVE. PER B737-NG AMM 32-41-31 PERFORMED SATISFACTORY BLEEDING UPSTREAM OF THE ANTI-SKID VALVES OPERTIONAL CHECK AND LEAK CHECK ON LEFT HAND BRAKE METERING VALVE. PER B737-NG AMM 31-41-00-870-801, NO ADDTIOINAL DEFECTS NOTED.

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