Field Service Bulletin
CNG Roof Mount Housing
Rubber Isolator Inspection and Repair

ENP-403
Rev C: September 16, 2016

1. Introduction
Vibration-dampening rubber strips are available for the CNG system framework on Dallas Area
Rapid Transit (DART) 40- and 31-foot CNG-fueled buses made by NABI Bus, LLC and equipped
with Agility Fuel Systems mounted on the vehicle roof.
These rubber strips were initially installed with a spray adhesive which is failing and the rubber
strips are falling off the system frames. In addition, similar rubber strips applied to the doors may
be in the same condition.

UPDATE:
Add strips of vinyl edge trim to
the doors as shown in Section
5, Step 5.

Figure 1 Rubber isolators on roof mount systems is coming loose and must be replaced.

Figure 2 Mounting surfaces must be cleaned and new adhesive applied.

ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

2 of 7

2. Affected Units
This procedure applies to part number 23905000 (40-foot) and 23906000 (31-foot) Agility Fuel
Systems CNG-fueled buses supplied to NABI Bus, LLC for Dallas Area Rapid Transit (DART).

3. Corrective Action 4. Special Tools, Materials and Required Parts
A new adhesive tape and proper surface preparation increases rubber isolator adhesion.
A torque wrench is needed when installing the hinge brackets.
QTY PER
VEHICLE

PART NUMBER

DESCRIPTION

Roll
1
Roll
19.5 Ft.

10802106
10802107
10802109
10802035

3M VHB Tape 4952, One-Inch Width
3M Primer 94
Rubber Strips
Self-Gripping Vinyl Edge Trim

WARNING
1) Wear appropriate personal protective equipment (PPE) and fall arrestment gear when
servicing roof-mounted systems.
2) Always be mindful of high pressure plumbing while working on the fuel system.
NOTE

System defuel is NOT required for this procedure.

5. Procedure – System Frame Rubber Isolators
1. It is not necessary to depressurize the system.
2. Refer to Figures 1 through 6. Remove all rubber strips away from the frame.
3. Prepare the mounting surfaces. Follow the manufacturer’s instructions for the 3M primer to
ensure proper adhesion.

Figure 3 Small rubber strips at the door hinges may also be affected by adhesive failure.
ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

3 of 7

Figure 4 Location of rubber strips on doors. There should be two strips on either side of the
hinge for a total of 8 pieces for each pair of doors.
4. Apply the adhesive tape per manufacturer’s instructions.

Figure 5 Rubber isolator locations for the 31-ft. system.

ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

4 of 7

Figure 6 Rubber isolator locations for the 40-ft. system.
5. ADD: Install sections of self-gripping vinyl edge trim to the front and rear curbside doors as
shown. The curbside doors are the ones with latches.

Figure 7 Front curbside door: Install rubber edging to the locations shown. One short piece
and one long piece is needed for each door. Forty-foot system shown.

ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

5 of 7

Figure 8 Rear curbside door: Install rubber edging to the locations shown. One short piece
and one long piece is needed for each door. Forty-foot system shown.

Figure 9 Example of installed edging. This is the short piece at the corner of a door.

8. Warranty Information
1. The standard Agility Fuel Systems warranty applies.
2. Standard repair time (SRT) for this procedure is 2 hours per vehicle.
If you have any questions, contact Agility Fuel Systems Product Support at 949-267-7745 or
[email protected].
ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

6 of 7

Agility Fuel Systems Product Support Group | 1815 Carnegie Ave. | Santa Ana, CA 92705 USA
Proprietary Statement
The information provided within this document is proprietary and confidential. All prior versions,
including updates and revisions forwarded separately, are proprietary. The information provided by
Agility Fuel Systems to its customers and clients is solely for the use of those customers and
clients. No portion of this manual may be reproduced or distributed without express written consent
of Agility Fuel Systems. Agility Fuel Systems reserves the right to utilize the intellectual property
contained within this publication as content for any other publication produced by Agility Fuel
Systems.
Trademark Notice
Agility Fuel Systems® is a registered trademark of Agility Fuel Systems. Drop-N-Go™ is a
trademark of Agility Fuel Systems. Trademarks of other manufacturers are the property of their
respective companies.
Revision

Description

Author

Editor

Approved By

Date

--

Initial Release

W. Yoshida

A. Bhakta

9/29/15

A

Rubber isolator inspection and
installation notes

W. Yoshida

A. Bhakta

6/14/16

B

Add self-gripping vinyl edge trim

J. Maycock

W. Yoshida

A. Bhakta

9/9/16

C

Customer comments added

J. Maycock

W. Yoshida

W. Yoshida

9/16/16

ENP-403: CNG Roof Mount Housing Rubber Isolator Inspection and Repair

7 of 7