Field Service Bulletin
Loose CNG Fill Receptacles

ENP-110414-303-F
November 4, 2014

1. Introduction
Refer to Figure 1. The high volume fill receptacle (Item 1) used in most Agility CNG fuel systems is
equipped with an adapter between the receptacle and the manifold assembly (Item 8). Because
both the fill receptacle and the manifold are equipped with female threads, the adapter has male
threads on both ends, see Figure 2.

Figure 1 CNG fill receptacles on a typical side mount fuel management module
High volume receptacles have been reported to come loose on some CNG vehicles in the field. If
the fill receptacle is loose, a leak may develop at the connection between the fill receptacle and the
adapter or between the adapter and the manifold. Most frequently, the leak develops at the
junction between the fill receptacle and the adapter fitting in the location indicated by the red arrow
in Figure 2.
It has been determined that the adapter was not adequately torqued to the fill receptacle during
initial assembly on some systems. (Proper torque, 45 to 50 Ft.-Lbs, ensures a reliable connection
over the life of the system.)
If this leaking or loose receptacle condition is experienced in the field, the fill receptacle should be
removed and re-attached with thread lock and torqued to spec, using the procedure in this bulletin.

Figure 2. The transit fill receptacle is a two-piece assembly. Some receptacles were
improperly assembled, causing the fitting to become loose.

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A corrective action was applied to all new production systems produced after October 31, 2014 to
address this issue.

2. Affected Units
This condition is limited to a small number of CNG systems.

3. Tools and Materials
1.
2.
3.
4.

High strength thread locker (red)
Strap wrench, ratchet drive (Snap-On A91E shown)
Torque wrench
Agility Fuel Systems torque grip enhancer, obtain this no-charge item by contacting Product
Support.
5. If the grip enhancer is unavailable, the fill receptacle can be wrapped with several layers of
duct or cloth tape to ensure adequate grip when using the strap wrench.

Figure 3 Tools and materials

Figure 4 Wrap the torque enhancer
around the fill receptacle

4. Procedure
WARNING
Depressurize system before starting work. Fittings should never be tightened or loosened
while under pressure.
A.
B.
C.
D.
E.
F.
G.

Close all CNG cylinder manual shutoff valves.
Verify the quarter turn shutoff valve on the FMM is open.
Start and run the engine until it stalls.
Access the bleed valve on the FMM manifold.
Open the bleed valve with a wrench.
Leave the bleed valve in the “OPEN” position.
All pressure gauges should read zero.

1. Remove the fill receptacle. This is a two-piece component.
a. If necessary, wrap the fill receptacle with the grip enhancer as shown in Figure 4. Use
masking tape if necessary to hold it in place.
2. Clean and dry the threads on the receptacle body and adapter, see Figure 5.

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Figure 5 Clean the receptacle threads

Figure 6 Apply thread locker, see step 3

3. Apply high strength thread locker to the first, second or third thread. The thread locker will
spread to the remaining threads when tightened. DO NOT allow thread locker to
contaminate the O-ring or the inside of the fill receptacle.
4. Use the strap wrench to tighten the fill receptacle to 45 to 50 Ft-Lbs., see Figures 7 and 8.

Figure 7 A close-up of the tool setup

Figure 8 Use the strap wrench to tighten
the receptacle to 45 to 50 Ft-Lbs.

5. Re-pressurize the system.
6. Test the fill receptacle
a. Connect the fill receptacle to a fill station nozzle.
b. Close all cylinder valves to restrict fuel flow to only the fill receptacle plumbing and
manifold.
c. Use leak detection solution to locate any leaks.
d. If leaks are found, depressurize the system and tighten the receptacle and adapter.
7. If no leaks are discovered, the repair is complete.

5. Warranty Information

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This procedure is covered under warranty. Standard repair time (SRT) is 0.5 hrs. Refer to
the Warranty Manual, ENP-067, for details on warranty reimbursement procedures.
If you have any questions about this procedure or have any concerns, please contact
Agility Fuel Systems Product Support at 949-267-7745 or [email protected].
Agility Fuel Systems
Product Support
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

Approved By

Date

--

Initial Release

W. Yoshida

Y. Coy

11/4/14

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