[Level 3] [NSEWL] T409(3711) Stuck Brake Departing AMK SB:
TC reported stuck brake at front DT(3711) car after departing AMK SB.
STBS was operated for train to proceed in ATPM to BSH SB for
disembarkation.Defective train was routed back to BSD TB3 and have
entered BSD. Spare train to be launched from BSD as replacement. ~~~~~ L3 From ER, 3711 brake pressure was intermittently high when brakes were supposed to be released.
During time of fault at 18:34H, 3711 brake pressure was at 0.21 bar compared to 0 bar at all other cars. Brake release relay was not energised.
TC activated STBS and proceeded in ATPM for withdrawal to depot.

From TIMS, observed 3711 FC323 BCU brake not released fault DT bogie 2, and FC311 BCU service brake available fault DT bogie 2.

Postulate that a faulty rio valve was unable to regulate the brake pressure.

- Changed out 3711 rio valve, found 3711 unable to read, TIMS showed brake system did not respond during self test.
- Changed out 3711 rio valve with another spare.
- Checked rio valve and gateway valve connectors were secured.
- All brakes able to physically apply and fully release during brake cyclic test, brake pressure checked satis.
- Brakes self test pass.
- Checked wheel and brake shoes conditions satis.

3711 Rio valve 1st change out
OLD SN: 1722018SPC
New SN: 1802094SPC
Notif: 2615128

3711 RIo Valve 2nd change out
OLD SN: 1802094SPC
NEW SN: 1805102SPC
Notif: 2615129

Done by: Koh/Jack
7.7.24