CNG Field Service Bulletin
Cylinder Mounting Block Bushing Replacement,
Part Number 240105-01
ENP-638
November 7, 2017
1. Introduction
CNG fuel systems and cylinders require routine and regular inspections to ensure safety
and durability. Inspection items include cylinders as well as a general overview of
structural components such as frame members, mounting bolts, vibration isolators and
other support hardware such as cylinder blocks and straps.
On some systems, a Delrin bushing (part number 240105-01) is incorporated into one of
the cylinder mounting blocks to accommodate normal cylinder movement due to
vibration and cylinder expansion and contraction. This is called the “sliding block.” The
other end is fixed and does not normally move, it is called the “fixed block” and does not
include a Delrin bushing.
The bushing will normally wear over time, and should be replaced if excessive wear is
discovered during the inspection process, to prevent damage to the cylinder.
This is a general procedure for all systems using Agility cylinders and sliding neck
blocks with a Delrin bushing, so the illustrations used here do not include system-
specific details.
Since components connected directly to the cylinder must be removed, the cylinder
being serviced must be defueled. Refer to “Safely Working on CNG Fuel Systems,”
Field Service Bulletin ENP-391 for proper and safe defueling guidelines.
Warning Messages Used in this Bulletin
Personal injury or death will occur if procedures are not followed.
Personal injury or death may occur if procedures are not followed.
Damage to equipment, fuel system or vehicle is possible if instructions are not followed.
2. Affected Units
This procedure applies to applications using sliding block part number 240105-01,
commonly used with 16-inch and 21-inch cylinder families. The part number is engraved
on the block.
3. Corrective Action
Regular inspection and maintenance should always include examination of all cylinder
mounting hardware – including cylinder mounting blocks and bushings.
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4. Tools, Parts and Materials
Normal fuel system service tools are used for this procedure. Compact ratchet tools will
help access fasteners in tight places.
Suitable lifting system/device for moving the cylinder up and out of the frame.
Bushing part number 16207-01.
Mounting block part number 240105-01 (if needed).
Retaining ring, part number 16210-325 (if needed).
Retaining plate, part number 16211-01 (if needed).
5. Procedure
A. Depressurize and defuel the system before starting work.
B. Use proper lifting techniques to prevent injuries.
Your fuel system and plumbing components may vary, this is a general instruction
intended for use with all systems and configurations using this block and bushing
mount.
1. Remove system covers and shields as needed to access the cylinder and
mounting blocks.
2. Remove all components from the cylinder (valve, fittings and tubing) and set
them aside in a clean, safe place.
3. Support cylinder with lifting sling near the sliding block end as shown in Figure 1.
Support sling
Fixed block Sliding block
Figure 1. Support the cylinder with a sling before loosening mounting hardware.
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4. While the cylinder is supported by the sling, remove mounting hardware
(Figure 2) and slightly lift the cylinder.
5. Pull the mounting block assembly away and off the cylinder boss neck (Figure
3). Do not use a pry bar or anything that could cause damage to the boss or
composite.
Figure 2. Remove the one piece top cover, end cap and D-plate.
Figure 3. Pull the neck block assembly away from the cylinder.
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6. Refer to Figures 4 and 5. Remove retaining ring from block assembly.
a. Insert a screwdriver into the removal notch.
b. Pry out the end of the first or top ring.
c. Grab the ring and “spiral it out” (use a pull and twist motion) of the groove.
d. If the retaining ring is damaged, replace it with part number 16210-325.
Figure 4. Pry the retaining ring out with a screwdriver, then pull and twist it to remove it
from the cylinder block.
Cylinder block
Delrin
bushing
Retaining
plate
Retaining ring
Figure 5. The cylinder block and bushing mounting assembly.
7. Replace the Delrin bushing and re-assemble the cylinder block.
a. Separate the 2 ring coils and insert one end into the retaining ring groove in
the block.
b. Press down and around the circumference of the ring to seat the ring into the
groove in the block.
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8. Slide the mounting block assembly and bushing onto the cylinder boss neck and
re-install mounting hardware.
Figure 6. Bolt the cylinder block assembly back onto the chassis.
9. Re-install all removed plumbing components.
10. Perform a leak test and fix any leaks.
11. Re-install the system covers and shields as needed.
12. Update the maintenance record for the vehicle.
13. Refuel and repressurize the system.
14. The vehicle can be returned to service.
6. Warranty Information
1. Standard warranty policy applies to this repair.
2. Standard repair time (SRT) is 0.5 hours (30 minutes) to remove and replace one
block and bushing assembly.
If you have any questions, contact Customer Care at +1 949 267 7745 or toll free at +1
855 500 2445 or e-mail: support@agilityfs.com
Parts can be ordered via e-mail: parts@agilityfs.com
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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 Solutions 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 Solutions. Agility Fuel
Solutions reserves the right to utilize the intellectual property contained within this
publication as content for any other publication produced by Agility Fuel Solutions.
Trademark Notice
Agility® and TUFFSHELL are registered trademarks of Agility Fuel Solutions. Drop-N-
Go™ is a trademark of Agility Fuel Solutions. Trademarks of other manufacturers are
the property of their respective companies.
Agility Fuel Solutions
3335 Susan Street, Suite 100
Costa Mesa, CA 92626
www.agilityfuelsolutions.com
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