FT4929
Service Bulletin Details
Public Details for: FT4929
Curb side front wheel air brake hose rubbing the inside of the wheel. Ft4929 to inspect and fix buses.
- 2019 -
Models from 2019
2019 NOVA BUS LFS |
FT4929 Curb side front wheel air brake hose rubbing Technical writer name Devanand First Level Parts Material Part Number - - QTY Manual section 08 Nb hours Level 1 Nb hours Level 2 0.5 hr MQR 7621-2141 1.5 hr - Disposal of parts Second Level Parts (33% of 38 vehicles) Material Part Number HOSE AIR BRAKE FRONT AXLE N45827 Shop Supply (33% of 38 vehicles) Material Part Number TIE TEFZEL CABLE TIES CABLE TIE N56339 504637 Client New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT New York City Transit New York - NYCT Order LA76 LC32 LC32 LC32 LC32 LC32 LC32 LC32 LC32 LC32 Removed parts are: QTY 1 Discarded X Retained - When the retained check box is check, the parts must be retained and returned in accordance with the usual warranty procedure to be reimbursed, QTY 3 6 Road numbers 8623 8633 8634 8641 8643 8643 8645 8645 8647 8654 8658 8658 8661 8664 8666 8666 8669 8669 8671 8672 VIN L82J8K9777144 L82J5K9777134 L82JXK9777145 L82J7K9777152 L82J0K9777154 L82J0K9777154 L82J4K9777156 L82J4K9777156 L82J8K9777158 L82J5K9777165 L82J2K9777169 L82J2K9777169 L82J2K9777172 L82J8K9777175 L82J1K9777177 L82J1K9777177 L82J1K9777180 L82J1K9777180 L82J5K9777182 L82J7K9777183 QTY Lang. Customer Target market Plant Config moteur Model E US TD 40 11 NYCT PLB 8 E US TD 40 NYCT PLB 1 E US TD 40 NYCT PLB 1 E US TD 40 NYCT PLB 8 E US TD 40 NYCT PLB 1 E US TD 40 NYCT PLB 4 E US TD 40 NYCT PLB 1 E US TD 40 NYCT PLB 1 E US TD 40 NYCT PLB 2 E US TD 40 NYCT PLB Jean-Nicolas Fournier NR x x x x x x x x x x R1 Digitally signed by Jean-Nicolas Fournier DN: cn=Jean-Nicolas Fournier, o=Nova Bus, [email protected], c=CA Date: 2020.08.21 11:05:59 -04'00' Brake hose internal campaign C/S and S/S front brake hoses NYCT LC32 Tools/parts required if replacement of hose is necessary • • • • • • • • • Wheel chocks/jack stands Lock-out/Tag-out Torque wrench 7/8” crows foot Ratchet with 10mm socket 10mm wrench Brake hose N45827 Blue zip ties N56339, X3 Black zip tie G5007995, X6 Brake hose rubbing tire Root Cause • While tightening the brake hose at the C/S front brake chamber some buses have had the brake line twist toward the front tire during the torqueing process, this is not present on the street side, this hose when torqued moves away from the tire due to it being the opposite direction as the curb side. A 30mm minimum of clearance is required between brake hose and tire Lock bus out • Place jack stands at yellow jacking points at the front of the bus, once complete, it is safe to measure inside the C/S and S/S wheel well. • Measure distance between brake hose and tire, turning the wheel to the right will make it easier if the bus is on the ground or it can be done with the wheels straight if the bus is in the air or over a pit. Measure distance between brake hose and tire at its closest point If there is less than 30MM and no contact between the brake hose and tire has been made, conduct the following procedure, keep bus locked out/chocked/stands in place Cut 2 blue zip ties, be sure to not cut into brake hose Loosen “P” Clamp With “P” Clamp loose, gently slide the hose toward the back of the bus until a minimum of 30mm is reached between the tire/brake hose. Re-tighten “P” clamp and re-install blue tie-wraps as originally oriented. Check connection at brake chamber • Verify the hose is not kinked/stressed where the fitting is crimped onto the hose at the brake chamber. If contact has been made: • The brake hose must be replaced. • The repair can be done with the bus on the ground with the wheel turned all the way to the right, over a pit, or on a lift. Follow all local safety procedures. Empty primary and secondary air tanks, red and green shown below Remove zip ties from brake hose for ABS and brake wear sensor • Be cautious when cutting, do not cut into cables Remove “P” clamps from brake hose X3 Disconnect air hose and discard Install new air hose into “P” clamps, follow routing shown below 34-38Nm Air hose installation continued Air hose installation continued • SAE 37° JIC flare fitting assembly instructions • 6.1.1 Inspect the contact surface and threads for any damage or material flaw. • (Do not apply sealer on threads.) Air hose installation continued • Use thread size to determine torque to be applied (see Table 5). • 6.1.4 Screw in the adapter or fitting by hand to ensure threads are correctly engaged • and finger tighten as much as possible. • 6.1.5 Using a wrench, complete tightening to the recommended torque (see Table 5). • 6.1.6 Apply anti-tamper seal (“Torque Seal”) to indicate torque has been applied (AVT-0203). Re-secure cables Re-secure cables on brake hose N56339 Continued from previous slide G5007994 X6 Measure brake hose to tire • Be sure the 30MM requirement is met. • If not, adjust hose as shown on previous slides Remove jack stands and unlock bus • Run bus until governor cut-out (approx 135PSI) • Turn steering wheel lock to lock several times. • Kneel bus and bring back to ride height. • With bus running and qualified personnel in the driver seat, release parking brake and depress brake pedal to the floor, have a helper check for leaks at the brake hose connections with snoop or soapy water, watch for bubbles. Leak check • If no leaks are present, the bus can be released • If leaks are detected, the connections must be disassembled, checked for damage and retorqued to 34-38NM, do not over-torque.