INSTRUCTION TO SERVICE
ITS61793

06/10/2026

SECTION:

549-HVAC System

SUBJECT:

Oil collection bottle and new shaft seal installation for testing.

ISSUE:

Testing new shaft seals. Collect and measure oil seeping through the shaft
seal.

SUMMARY:

Install oil collection bottle and replace shaft seal per this ITS

ITS61793
Ref. NHTSA Recall No.
Not Applicable

Ref. Transport Canada Recall No.
Not Applicable

THIS ITS DOCUMENT SHOULD BE RETAINED AND REFERRED TO FOR FUTURE MAINTENANCE UNTIL
THE PARTS AND/OR SERVICE MANUAL IS UPDATED TO REFLECT WORK DONE AS A RESULT OF THIS
DOCUMENT. ENSURE THAT THIS DOCUMENT IS AVAILABLE FOR PARTS AND MAINTENANCE STAFF
GOING FORWARD.
This document and the contents discussed herein are the confidential and proprietary information of New Flyer Industries Canada ULC and New Flyer of America Inc. and are disclosed by New Flyer in
confidence. This document and the contents herein are not to be disclosed by the intended recipient without the prior written authorization of New Flyer. Any unauthorized disclosure, reproduction or other
distribution of this document or information strictly prohibited and may result in action being taken against the party making the unauthorized disclosure. This document and all copies hereof must be returned
to New Flyer upon request.

INSTRUCTION TO SERVICE
ITS61793

SAFETY PRECAUTIONS MUST BE FOLLOWED ACCORDING TO ACCEPTED INDUSTRY
STANDARDS AND LOCAL/PROPERTY REQUIREMENTS.

PROCEDURE:
1. Set parking brake and place wheel chocks underneath the front wheels.
2. Turn the main battery disconnect switch to the “OFF” position. Turn the rear run selector switch to the “OFF”
position. Refer to Figure 1.

Figure 1: Rear run selector switch
3. Open curb side and rear engine compartment access doors and locate the HVAC compressor.

HVAC compressor

Figure 2: Location of the HVAC compressor

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4. Remove handle of the dump valve so it won’t be activated accidentally while working in this area. Refer to
Figure 2a.

Figure 2a: Remove handle from dump valve
5. Remove the oil collection tube from its bracket and discard hose. Leave the bracket on the compressor.
Note: removing this tube may be difficult without removing the clutch. If shaft seal is being replaced and
clutch is off, then remove existing short tube and install the new 900 mm long tube at that time. As an
alternative, a brass union-fitting (PN 1146249) can be used to connect the existing short tube with the new
900 mm tube so there is no need to remove the existing tube from the compressor. Cut the long tube as
required in this case.
Original location of the oil collection
tube and its bracket. Remove tube
from this bracket and discard tube.
Leave the bracket on the compressor.

Figure 3: Original location of the oil collection tube

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6. Install new 4mm ID x 900 mm long hose (PN 1173413) and route it towards the RH side of the coach as
shown below. Refer to Figure 4.

Routing of the new 900 mm
long oil collection tube

Figure 4: Connect and route new tube
7. Locate the 3/8-size bolt and large washer at the RH rear frame as shown on the photo below. Remove bolt.
Refer to Figure 5 below.

Figure 5: Existing bolt at the RH rear frame

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8. Use the short bracket provided with the KIT (PN 6494537) as shown on Figure 6 below.

Use this short
bracket from the KIT.

Figure 6: Bracket
9. Install original flat washer then bracket to the rear frame member with the original 3/8-size bolt. Apply Loctite243 thread locker (PN 081034) to the first two threads of the bolt. Refer to Figure 7 below.

Bracket

3/8 bolt

Figure 7: Install bracket to the frame

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10. Secure the top of the collection bottle with the 6 mm (gold-color metric size) bolt supplied with the KIT. Apply
Loctite-243 thread locker (PN 081034) to the first two threads of the bolt supplied with the oil collection bottle
kit.
Apply Loctite-243
PN 081034

Figure 8: Install top part of the collection bottle to the bracket
11. Drill a ¼” diameter hole on the compressor bracket to mount the small bracket (PN 904661) that will secure
the hose. Deburr hole. Refer to Figures 9a and 9b below.

Bracket PN 904661
¼” diameter hole

1”

Figure 9a: Install bracket for the hose

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¼-20x1.00” SST bolt
(PN 20B04016), flat
washer (PN 50W04000)
and nut (PN 42N04000)
P-clamp PN 247217
If brass union-fitting
was used to extend
existing short tube

Figure 9b: Install bracket for the hose
12. Secure new tube to the bracket with a P-clamp (PN 247217), ¼-20x1.00” SST bolt (PN 20B04016), 2 ea. flat
washer (PN 50W04000) and nut (PN 42N04000). Refer to Figure 9.
13. Secure oil collection bottle to the head piece. Refer to Figure 10.

Figure 10: Install bottle and hose
14. Connect new hose to the oil collection bottle.
15. Reinstall handle of the dump valve. Refer to Figure 2a.

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Shaft Seal Replacement
Note: person who will perform the shaft seal replacement detailed below must be certified to handle refrigerant.
16. Front seat service valves on suction and discharge ports of the compressor to isolate compressor from the
rest of the HVAC system. Refer to Figure 11.

Discharge side
service valve
Suction side
service valve

Figure 11: Front seat service valves of the HVAC compressor
17. Remove refrigerant from the compressor. Use a scale to measure the amount of the refrigerant removed. The
same amount of refrigerant needs to be recharged after the shaft seal replacement has been completed.

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18. Remove HVAC compressor belt(s). Refer to Figure 12.

Wood block

Pry bar

Figure 12: Use a pry bar with wood block underneath to tilt HVAC compressor then remove belt(s)
19. Disconnect electrical wire from the clutch then remove clutch. It is preferred to use the puller bolt (PN T201254) but if the puller bolt doesn’t work then as a second option, use the 3-bolt type puller as shown below.
Do not use impact gun on puller bolts. Ensure not to damage (bend) the pulley. Refer to Figure 13.

Figure 13: 3-bolt type puller as a second option to remove clutch-pulley assembly

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20. Follow shaft seal replacement procedure detailed in the HVAC compressor supplier’s instruction attached to
the Appendix. Also refer to the official Bitzer shaft seal replacement videos on YouTube.

Important:
21. Ensure to wear gloves when handling shaft seals. The new shaft seal can’t be touched by bare hands!
22. The used shaft seals must be saved for the supplier for further inspection. Ensure that the used shaft seals
are placed into the same plastic container that the new shaft seals are packed. Refer to Figure 14.

Figure 14: Plastic container of shaft seals
23. Contact your local MCI representative about how and where to ship these removed used shaft seals.
24. Apply a thin coat of anti-seize lubricant onto the tapered portion of the compressor shaft then reinstall clutch
to the compressor shaft. Torque center mounting bolt to 63 ft-lbs. (85 Nm). Reconnect electrical wire to the
clutch coil.
25. Slowly turn compressor shaft consistently 25 times clockwise direction to lubricate shaft seal.
26. Reinstall HVAC belt(s). Check tension and alignment and adjust as required. Refer to your MCI Maintenance
Manual for adjusting HVAC belt(s).

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27. Ensure oil level is correct inside the HVAC compressor. Direct your flashlight inside the compressor through
one of the sight glasses to illuminate oil inside the compressor, then check oil level at the opposite sight glass.
Then perform the same inspection on the opposite sight glass. The oil level must be correct on both sight
glasses. Refill oil if required Oil must be clean, clear in color. If oil is brownish or more than 3 years old, then it
is a good time to drain oil and fill up with new Bitzer BSE 55 polyester refrigerant oil (PN 16-02-1272). Refer
to Figure 15.

Figure 15: Check oil level
28. Vacuum the compressor down to 400 µm-Hg (“microns”), stop vacuum pump and wait 10 minutes and ensure
it stays below 800 microns. If it doesn’t hold vacuum, check for leaks (check for bubbles at sight glasses,
check service valves, threads of pressure transducers and fittings). If compressor holds vacuum, then
recharge HVAC system according to the MCI Maintenance Manual.
29. Check for completeness of the work.
30. Record HVAC compressor hours, mileage of the coach and the date of completion of this rework.
Provide this information to your local MCI representative.
31. Remove all tools and debris from work area to return coach to service.
32. Turn the main battery disconnect switch to the “ON” position.

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LABOUR ESTIMATE
Operation
1

Install oil collection bottle and replace seal per this ITS

Number of
Technician(s)
1

Hours
5

Labor Time
T X HR
5

PARTS REQUIRED
Qty.
per
Coach

Item

Part Number

Description

1

20b04016

BOLT HX SS 1/4X1.00

2

each

2

42N04000

NUT-NYLON LOCK 1/4-20 UNC SST

2

each

3

50w04000

WASHER-FLAT 1/4 NOM

4

each

4

081034

LOCTITE-243 MEDIUM 10ML

0.01

each

5

247217

CLAMP-P 0.250

1

each

6

904661

BRKT-BAE VENT LINE SPRT

1

each

7

1173413

Hose, 4 mm x 900 mm

1

each

8

6494537

BOTTLE COLLECTION KIT COMPRESSOR OIL

1

each

9

1177757

SHAFT SEAL KIT

1

each

10

1146249

1

each

Qty.

Units

FITTING-BRASS STRAIGHT UNION 3/16 BARB
X 3/16 BARB

Units

Notes

Only if existing tube
can’t be removed see
Notes at Step 5

SPECIAL TOOLS REQUIRED
Item

Part Number

1

NA

HVAC refrigerant recovery tool, vacuum pump

1

EA

2

NA

Vacuum micron gauge

1

EA

3

T20-1254

Clutch puller bolt

1

EA

4

NA

Scale to weight refrigerant

1

EA

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Description

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Notes

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Appendix – Shaft Seal Replacement

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