SAV.1E.2012MA

BS4173E

NOTE

For a complement of technical information during this procedure, refer to the guidelines in section 99-000.00
of the Nova Bus Mantenance Manual.

LEVEL 1: REPLACE A SEGMENT OF FLEXIBLE HOSES
1.1.

Set the battery disconnect switch in the battery compartment to the off position.

Battery disconnect
switch in OFF
position

Light to indicate
if main power is
on or off

Figure 3 - Battery Disconnect Switch

1.2.

Place a container under the coolant drain valve.

1.3.

Drain the cooling system per the heading Draining the cooling system in section 09-302: Engine cooling
in the Nova Bus Maintenance Manual. Retain the coolant.

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BS4173E

REAR SIDE
1.4.

Remove the first baselight panel located closest to the articulation. Retain the baselight panel and hardware.

1.5.

In the articulation, detach the folding bellows roof cover from the side (not from the middle) and push it toward
the middle. Retain parts for reinstallation.

Bellows roof cover

Figure 4 - Bellows Roof Cover to Detach From the Side

1.6.

Loosen the 4 bolts under the cap and saddle bracket located before the EGS.

Loosen the 4 bolts
under the bracket

Figure 5 - Cap and Saddle Bracket in the Articulation (Rear Side)

1.7.

Disconnect the two flexible hoses from the Pex tubing; start by cutting some cable ties on each side of the
clamps, then remove the clamps (retain them for later). Have a container handy in case there is coolant still
in hoses.

- Cut cable Ties
- Remove clamps

Figure 6 - Flexible Hoses on the Rear Side
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1.8.

SAV.1E.2012MA

BS4173E

From the articulation side, pull the hoses to completely bring them to the articulation side.

Pull the hoses...

completely...

toward the
articulation side.

Figure 7 - Flexible Hoses Brought to the Articulation Side

1.9.

Remove the insulation covering the Pex tubes.

1.10.

Measure PRECISELY (see the warning below) the length to cut starting at the front edge of the bracket. Mark
the location on each tube. Then cut the tubes.
WARNING

The measure must be very precise otherwise it could create an interference at the other end of the assembly
with the hoses, pipes and cables coming out of the EGS, therefore, requiring the Level 2 procedure.

7½ in (190 mm)

Figure 8 - Length to Precisely Cut on the Rear Side

N90354

7½ in
(190 mm)

N90356

Figure 9 - Schematic of the Change (Rear Side)

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BS4173E

SERVICE BULLETIN
1.11.

Remove the caps at the end of the copper pipes.

1.12.

Insert the copper pipe N90354 (outer side). Insert the copper pipe N90356 (inner side) in front of the outer pipe.

N90354

N90356

Copper pipe

Figure 10 - Copper Pipes Coming From the Articulation Side (Temporary Position)

1.13.

Slide the PEX ring N45715 over the end of the
stop edge.

1.14.

Expand the tube and the ring (using an expansion tool), then quickly insert and align properly the copper
pipe N90354. The pipe must be horizontally aligned for its connection with the hose.

outer

PEX tube, beveled side first, until it reaches the

N90354
Horizontal
alignment

Figure 11 - Copper Pipe Installation Horizontally Aligned

1.15.

Repeat steps 1.13 and 1.14 to install the inner copper pipe N90356. See Figure 2 for the schematic view.

1.16.

On the articulation side, assess where to cut the hose by placing the flexible hoses and copper pipes side
by side. The hose must reach the shoulder on the copper pipe. Validate if the new pipes interfere with
the hoses, pipes, and cables coming out of the EGS. If the copper pipes do not align properly with
the flexible hoses, or if there is a risk of rubbing between parts (including the clamps), the length of
the PEX tube has to be adjusted according to the level 2 procedure.

1.17.

Mark the location and cut the hoses.

Shoulder

Figure 12 - Mesure and Cut the Flexible Hoses

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BS4173E

SERVICE BULLETIN
1.18.

Slide the clamps (retained earlier) onto the hoses, and slide up the hose's fabric sheath.

1.19.

Insert the copper pipes into the hoses. Do not use lubricant or the expansion tool to ease insertion – only
coolant should be used to ease the insertion.

1.20.

Validate again if the position of the assembly interferes with the other hoses, pipes, and cables coming
out of the EGS. If there is interference, proceed to level 2.

1.21.

Lower the fabric sheath onto the hoses. Place and tighten the clamps. See the torque in the figure below.

66 ± 4 lb-in
(7.5 ± 0.5 N•m)

Figure 13 - Clamps on the Flexible Hoses

1.22.

Remove the Cap and saddle bracket. Reinstall the top section with the new middle section (N92161-02) and
bottom section (N92161-03) using the same hardware. Tighten the bolts. See the figure below for the right
parts positioning and torque.

Top section
to keep

Torque x 7 bolts:
89 ± 9 lb-in
(10 ± 1 N•m)

New
N92161-02
N92161-03

Figure 14 - Parts Positioning in the Cap and Saddle Bracket - REAR View. (Some options may not apply)

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BS4173E

FRONT SIDE
1.23.

On the front side repeat steps 1.4 to 1.22.

N90355

N90353

4¾ in (120 mm)

Figure 15 - Distance of the Cut on the Front Side

AIR TESTING
1.24.

Connect an air hose equipped with a pressure regulator to the quick-connect fitting, and set the pressure to
10 psi. Visually validate if there is a leak on the newly installed piping. Repair as needed.

Pressure regulator
set at 10 psi

Figure 16 - Hose Equipped with a Pressure Regulator

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BS4173E

FINAL STEPS BOTH SIDES
1.25.

Replace the 4 Tyton cable ties previously cut with the new ones (N69299) and affix the PEX tubes to these
anchor points.

1.26.

Put the insulation on the copper pipes. Do not put it over the fitting or the Tyton cable ties.

Figure 17 - Insulation on the Copper Pipes

1.27.

Fill the cooling circuit with the retained coolant according to the procedure indicated in section 09-302: Engine
cooling of the Nova Bus Maintenance Manual.

1.28.

Install the retained baselight panels.

1.29.

Install the ceiling curtains and the parts removed for access.

1.30.

Set the battery disconnect switch in the battery compartment to the on position.

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BS4173E

LEVEL 2: ADJUSTING A PEX TUBE LENGTH

Tube length that
needed adjustment

Fitting extension
must not be
under the
bracket

Tube length ok
the first time

Figure 18 - General View of a length Adjustment (FRONT side)

2.1.

From the articulation side, estimate how long the PEX tube should be. Calculate the length of the PEX tubes
that need to be cut (2 tubes in the vehicle, and the piece of PEX N45726 to be added) to obtain a pex-ringfitting-ring-pex assembly of the required final length. Be aware that the position of the fitting must not
be under the bracket – where the cable tie will attach it later.
Fitting N91167

Tubing N45726

Ring N45715

Figure 19 - Parts Needed for the Extension

2.2.

Measure and mark the PEX tubes.

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SERVICE BULLETIN
2.3.

SAV.1E.2012MA

BS4173E

Disconnect the copper pipes.
CAUTION

To disconnect the pipes, follow the guidelines in the extract from the Uponor PEX Assistance manual in
Appendix 1 or HePEX heating pipes heading in Section 99: General Practices in the Nova Bus Maintenance
Manual.

Cutting lines
(distance
shown only as
example)

Figure 20 - Disconnecting the Pipes

2.4.

Cut the PEX tubes.

2.5.

Install the PEX extension as shown in the figure below.
Brass fitting N91167

Tubing N45726

Ring N45715

Figure 21 - Extension of the Tubing

2.6.

Repeat steps 1.13 and 1.14 to reinstall the copper pipes.

2.7.

Validate if the position of the assembly doesn't interfere with the other hoses, pipes, and cables coming out
of the EGS.

2.8.

When the position of the assembly is satisfactory, resume the process from step 1.21.



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BS4173E

APPENDIX 1:

UPONOR ASSISTANCE MANUAL, CHAPTER 2
Chapter 2::

Making ProPEX Connections
This document shows how to make
proper ProPEX connections using one
of the following tools.

Uponor ProPEX ASTM F1960 and
CAN/CSA B137.5 cold-expansion
fittings make solid, permanent,
manufactured connections without
the need for torches, glues, solder,
flux or gauges. The unique shape
memory of Uponor PEX piping
forms a tight seal around the fitting,
creating a strong, reliable connection.

• Milwaukee® M12™ or M18™
ProPEX Expansion Tools
• Milwaukee M18 FORCELOGIC™
ProPEX Expansion Tool
• ProPEX 201 Corded Expander Tool

Distance Between Fittings
Uponor requires a minimum distance
between ProPEX fittings to ensure
the fittings are not damaged during
the expansion process by the
expander head. Refer to Table 2-2
for the minimum distance between
fittings, which is expressed as cut
length of pipe.

• ProPEX Hand Expander Tool

General ProPEX Connection Tips
• Ensure the ProPEX Ring rests
snugly against the fitting shoulder.
If there is more than 1⁄16" (1mm)
between the ring and the shoulder
of the fitting, the connection must
be replaced. Square cut the piping
2" away from the fitting for ½"
to 1" pipe, 3" away for 1¼" to
2" pipe and 5" away for 2½"
and 3" pipe prior to making the
new connection.

• If the fitting does not slide into
the piping all the way to the stop,
immediately remove it from the
piping and expand the piping one
final time.
Note: To avoid over-expanding
the piping, do not hold the piping
in the expanded position.
• Table 2-1 shows the recommended
number of expansions. Experience,
technique and weather conditions
influence the actual number of
expansions. Fewer expansions may
be necessary under certain
conditions. The correct number
of expansions is the amount
necessary for the piping and
the shoulder of the fitting to
fit snugly together.

Piping Size
/"

3 8

½"
¾"
1"
1¼"
1½"
2"
2½"
3"

• Brass ProPEX fittings can be
disconnected and reused. EP
fittings must be discarded. Be
sure to follow the recommended
minimum distance between
ProPEX fittings shown in
Table 2-2.

Milwaukee ProPEX Tool