Field Service Bulletin
Mack UPS CNG BTC Bracket Repair

ENP-264
August 14, 2014

Mack UPS CNG BTC Bracket Repair

1. Introduction
A production run on 10 UPS CNG vehicles with a unique configuration of BTC and frame mounting
hardware. This repair is authorized to bring vehicles back to Agility engineering standard.

2. Affected Units
10 UPS MACK CXU633T Pinnacle tractors equipped with the CNG 20319000 100 DGE system
built at the Agility Fontana facility are affected. Bracket mounting plates contained in assembly
20307018 were not built to Agility engineering spec causing hardware interference.

3. Corrective Action
These units will have corrected brackets installed in conjunction with approved hardware from
Mack and Agility Engineering standards.

Figure 1. UPS MACK CXU633T with 203 series BTC system.

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

2 of 16

Mack UPS CNG BTC Bracket Repair

4. Procedure
Material Needed For Field Service Repair
1) Hardware for installation repair
a) 14mm x 50mm grade 10.9 flange head bolts
b) 5/8” x 2 1/2” Grade 8 flange head bolts
c) 14mm grade “G” top lock flange nuts with flat non-serrated mating surface
d) 5/8” grade 8 top lock flange nuts with flat non-serrated mating surface
2) Mounting brackets needed
a) 20307127 X 2 per vehicle (Appendix A)
b) 20307128 X 2 per vehicle
3) Thread-locker
RTV silicone

Preparing Vehicle for Service
1) System needs to be depressurized as stated in ENP-007 Universal CNG
Operations Manual (Appendix B) or Field Service Training Program (Appendix C) if
system removal is necessary.

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

3 of 16

Mack UPS CNG BTC Bracket Repair

Figure 2. Rear accessories attached to BTC cabinet.

2) Uninstall BTC tractor options
3) Disconnect fuel system coolant lines, low pressure lines and wiring harness from
underneath the BTC.

Replacing BTC Mounting Brackets and Hardware

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

4 of 16

Mack UPS CNG BTC Bracket Repair

Figure 3. Views of nonconforming hardware and clearance standards on customer vehicle.

1) Connect supporting equipment to the eyebolts on the top of the BTC.
2) Uninstall 5/8” hardware that attaches to the lower BTC structure. Remove current
BTC mounting hardware from chassis frame.
3) Remove current mounting bracket and tag.

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

5 of 16

Mack UPS CNG BTC Bracket Repair

Inspecting UPS Frame Rail

Figure 4. Frame rail inspection, drilling and prep

1) Inspect predrilled holes. Identify holes are not predrilled through chassis cross
members.
2) Please refer to Quality Alert (Appendix D)
3) Ream approved holes to 5/8” hole size where it is approved.

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

6 of 16

Mack UPS CNG BTC Bracket Repair

Installing New Mounting Brackets and Hardware to BTC and Chassis

Figure 5. New hardware and proper bracket.

1) Install a NEW rubber isolator on to new mounting brackets
2) Install 5/8” grade 8 flange bolt and 5/8” grade 8 top lock flange nut into holes that
have been reamed.
3) Install 14mm X 50mm grade 10.9 flange bolts and 14mm grade 10.9 top lock flange
nuts into holes that have not been reamed.
4) Make sure that ALL predrilled holes are filled with either 5/8” hardware where NO
cross member is present AND 14mm hardware where there is a cross member
present.
5) Each bracket must have a minimum of 4 bolts per bracket.
6) Install 5/8” hex cap bolt and washer into the top of BTC mounting brackets to attach
to brackets to BTC system.
7) Reattach the BTC system and install 5/8” hardware per the procedure in document
PRF-052 (Appendix E).

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

7 of 16

Mack UPS CNG BTC Bracket Repair

Application of Thread Locker to Accessible Cover Assembly Hardware
1) One at a time remove cover assembly bolts and apply the approved medium
strength RTV silicone thread locker as directed in ENP-065 (Appendix F). The bolts
most prone to loosening are the 3 lower central bolt locations on the back and the
front of the system. These should all be checked for torque.
2) Re-torque all cover bolts to 25 ft-lbs.
3) Check all remaining cover hardware.

Figure 6. Images showing cover bolt locations

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

8 of 16

Mack UPS CNG BTC Bracket Repair

Figure 7. Potential loosening cover bolt locations (opposite side not shown but should be checked)

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy

9 of 16

Mack UPS CNG BTC Bracket Repair

Re-Installing BTC accessories:

1)
2)
3)
4)
5)

Reinstall double spring hangers back on the BTC slide bars
Reinstall BTC air and electric brackets and lines to the BTC system
Reinstall coolant and engine fuel lines to the BTC FMM
Reapply warning decals to BTC extrusions (if necessary)
Re-pressurize vehicle lines

Standard repair and warranty labor period per the Agility Fuel Systems Warranty Manual applies
for this procedure. Time to complete this procedure is 5 hours. This procedure is limited to the
initial 10 Mack – UPS vehicles as mentioned in the introduction section.
If you have any questions, contact Agility Fuel Systems Product Support at +1-949-267-7745 or
[email protected].
Agility Fuel Systems
Product Support
1815 Carnegie Ave
Santa Ana, CA 92705 USA
+1-949-267-7745
[email protected]
www.agilityfs.com

ENP-264 Rev- Date: 8-14-14

Revision History

--

--

MG

8/14/14

Initial release

ECN#

REV

BY

DATE

DESCRIPTION

Printed copy is uncontrolled

Approved by: Y. Coy 10 of 16

Mack UPS CNG BTC Bracket Repair

Appendix A

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 11 of 16

Mack UPS CNG BTC Bracket Repair

Appendix B

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 12 of 16

Mack UPS CNG BTC Bracket Repair

Appendix C

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 13 of 16

Mack UPS CNG BTC Bracket Repair

Appendix D

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 14 of 16

Mack UPS CNG BTC Bracket Repair

Appendix E

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 15 of 16

Mack UPS CNG BTC Bracket Repair

Appendix F

Figure 4.

ENP-264 Rev- Date: 8-14-14

Printed copy is uncontrolled

Approved by: Y. Coy 16 of 16