SB-10054615-6795
LFW: Corrosion Repair

Prepared by:

Kalman Takacs
Sr. Field Service Engineer

Approved by:

Dan Allen
Chief Engineer

Property name and Top bus number:

NABI LFW

Issue:

Corrosion issues were reported by the customer.

Solution:

Repair the effected area per this work instruction.

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

1

LFW: Corrosion Repair

Effected buses: as required
Estimate repair hours/bus: 16 hours/bus
Necessary parts:
POR 15 Rust Preventive, 1 QT,
Rubberized undercoating, 1 QT,
Sikaflex 221, sealer, white,
Acetone,

Part #: NPN,
Part #: 700-2603-003,
Part #: 416.00.7311.909,
Part #: NPN,

as required (1/4 buses),
as required (1/4 buses),
as required,
as required

See some pictures below about the possible usable products.

Example

Necessary tools:
Usual hand tools (wrenches, screwdrivers, hammer, chisel, etc.) putty knife, Sika applicator gun, angle
grinder, wire wheel, 36G and 60G abrasive discs, de-burr bits

Example
Example

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

2

LFW: Corrosion Repair

SAFETY PRECAUTIONS MUST BE FOLLOWED ACCORDING TO ACCEPTED INDUSTRY
STANDARDS AND LOCAL/PROPERTY REQUIREMENTS.
Stop welding 45 minutes before planning to leave the bus.
1. For the chassis inspection/repair the bus needs to be lifted. Place wheel lifts underneath the
wheels and lift the bus approximately 2 feet from the ground. Follow safety precautions
when lifting the bus. Only trained personnel can operate bus lift!
2. If bus parked on a scissors type lift then apply parking brake and also place wheel chocks
underneath the B-axle wheels.
3. Turn off the battery disconnect switches.

4. Lift the bus up as high as required to perform inspection/repair underneath the bus. Follow
safety precautions when lifting the bus. Only trained personnel can operate bus lift!
Use jack stands underneath the official jacking pads.

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

3

LFW: Corrosion Repair

5. Inspect chassis from front to back and identify areas (if any) that needs to be repaired (see
some examples below). If corrosion was found follow the steps written below. The below
repair is an example and other area of the chassis should be repaired the same way.

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

4

LFW: Corrosion Repair

6. Remove nearby components (clamps, hoses, bolts, suspension components, etc.) as
required (See some examples below.). Drain cooling and/or hydraulic system as required.
Follow the safety precautions and recommendation of NABI Maintenance Manual.
Remove radius rod to get access
to the corroded area above

Remove hardware to get access to the chassis.

Install new bolt and washer.

Remove hoses to get access to the corroded area.
Follow NABI Maintenance Manual instructions
when disconnect air system components!

Work instruction number: L3/FSV-212
L4/QUA-003

Remove clamp and hose to get access to the
corroded area.

Revision: Initial

Date: 11/22/2013
Revision: Initial

5

LFW: Corrosion Repair

Remove clamp and move hoses to gain access to
the corroded area.

Remove gauges and remove bracket. Install new
bracket.

7. Remove loose undercoating by using scraper.
8. Remove corrosion from the effected area. Use electric grinder first then the 36G abrasive
wheel and finally the 60G abrasive wheel. Use different size and shape of wire wheels as
required. Ensure that all corrosion is removed.
Original condition of the chassis (example).

Loose paint and corrosion
removed.

9. Degrease surface with acetone.

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

6

LFW: Corrosion Repair

10. Apply POR 15 to the degreased area. Follow instruction written on the can. Let POR 15
dries before proceeding with the next step.

11. If Sikaflex sealer was present originally (for example between the top edges of structural
tubes and floor panels) then reapply Sikaflex 221 sealer as required.
12. After the POR 15 (and or Sikaflex 221) dried apply undercoating to the primed area. Follow
instructions written on the can.
Final operation
13. Reinstall previously removed components.
14. Install new hardware as required.
15. Torque hardware per NABI Maintenance Manual.
16. Lower the bus.
17. Refill cooling and/or hydraulic system if they were drained.
18. Turn battery disconnect switches on.
19. Start the bus (certified technician) and ensure that no warning lights (check engine, check
transmission, etc.) are on.
20. De-aerate cooling and/or hydraulic system per NABI Maintenance Manual as required.
21. Present the repaired bus for inspection to a delegated person.
22. Record bus number, mileage, date of completing and the name of the technician who
completed the repair.

Work instruction number: L3/FSV-212
L4/QUA-003

Revision: Initial

Date: 11/22/2013
Revision: Initial

7