SB-10054151-7619

INSTRUCTION TO SERVICE
ITS: 5591
SECTION:

231

WRITTEN BY:

Michael Rooney

SUBJECT:

ISE Cooling Loop Bypass Removal

Cooling System

ITS5591

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 UNAUTHOIZED DISCLOSURE, REPRODUCTION OR
OTHER DISTRIBUTION OF THIS DOCUMENT OR INFORMATION IS 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.

PROCEDURE:
1. Turn the main battery disconnect switch to the “OFF” position.
WARNING:

ALWAYS discharge the Ultra Capacitors before performing maintenance on this
vehicle. Refer to Section 5 of the service manual under 2.17 Discharging the Ultra
Capacitors for the discharge procedure.

2. Locate the center three chesterfield seats at the rear of the passenger compartment. Pivot the seats upward
and install the prop rod to allow access to the removable panels under and behind the seats. Figure 1.
NOTE:

Take care while working around the raised seats, head clearance is limited.

3. Using a square key, release the access cover latches and remove the access covers. Figure 1.

Raised Seats
Access Openings,
Covers Removed.
Prop Rod

Figure 1: Access Openings Under The Chesterfield Seats.

4. Locate the upper and lower coolant manifolds, generator and two electric drive motors. Figure 2.
5. Check to ensure that upper manifold header and components are plumbed as follows: Figure 2.
a.

Street side branch of the upper manifold header should be closed off.

b.

Second from street side branch of the upper manifold header should be plumbed to the street side port
of the street side electric drive motor.

c.

Curb side branch of the upper manifold heater should be plumbed to the lower port of the generator.

d.

Second from curbside branch of the upper manifold header should be plumbed to the streetside port of
the curbside electric drive motor.

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ITS: 5591

6. Check to ensure that lower manifold header and components are plumbed as follows: Figure 2.
a.

Street side branch of the lower manifold header should be plumbed to the coolant pump.

b.

Second from street side branch of the lower manifold header should be plumbed to the curb side port of
the street side electric drive motor.

c.

Curb side branch of the lower manifold heater should be plumbed to the upper port of the generator.

d.

Second from curbside branch of the lower manifold header should be plumbed to the curb side port of
the curbside electric drive motor.

NOTE:

Most buses have a bypass hose connecting the upper and lower manifold headers as well
as a Y-connection to the electric drive motors which will require modification.

Curb Side

Street Side

Upper Manifold Header
Lower Manifold Header

To Curb Side Port of Street
Side Motor
Install p/n
6431573
Cap here

Generator
To Street Side
Port of Street
side Motor
To Curb side
Port of
Curbside
Motor

To Street Side Port of Curb
Side Motor

Street Side Motor

To Lower Port
of Generator

Curb Side Motor

To Upper Port
of Generator

To Pump

Figure 2: Hose Layout on Upper/Lower Manifold Headers

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ITS: 5591

7. If the hose layout at the upper and lower manifold headers does not match Figure 2 and or the bypass hose is
present, the hoses will have to be reconfigured.
a.

Drain the coolant from the electronics cooling loop.

b.

Change the hose connections as necessary to match the configuration shown in Figure 2. Use ¾” hose
NF P/N 106197 and hose clamps NF P/N 274935 as needed. Torque hose clamps to 56-62 IN-LBS.

c.

Refill the cooling system.

8. Locate the street side branch of the upper manifold. Figure 2.
a.

Use a Rotary Tube Cutter to cut the end of the tube to remove the bead.

b.

Check that the end cut is square and that there are no burrs or damage. Use some emery paper to clean
up the exterior surface of the tube if necessary.

c.

Install the nut, washer and tapered washer from the cap NF P/N 6431573 over the tube. Fig 3, Picture
#1.

d.

Push the plug into the end of the tube and install the nut on the plug finger tight then turn an additional ¼
turn. Fig 3, Picture #2.

Nut

Nut

Washer

Plug
Tapered
Washer

Figure 3: Bypass Tube Plug Installation.

9. Open the curb side rear access door and locate the coolant circulation pump.
10. Check to make sure that the hoses are connected according to Figure 4.

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ITS: 5591

Coolant Circulation Pump
To Lower Manifold Header
Hose Barb

P-Clamps

Figure 4: Hose Layout at Coolant Circulation Pump.

11. Disconnect the hose that connects the manifold to the pump at the pump hose barb. Figure 4
12. Remove the P-clamps that locate the hose and remove the hose. Figure 4.
13. Remove the hose barb threaded into the pump and replace with the new hose barb NF P/N 218169.
NOTE:

To prevent leaks it is necessary to use NPT thread sealant on the hose barb threads.

14. Install a new length of hose NF P/N 106197 from the pump hose barb to the coolant manifold and secure with
new P-clamps NF P/N 247227 in the original locations. Figure 4.
15. Refill the cooling system and check for leaks.
16. Re-install the access covers.
17. Lower the rear chesterfield seats.
18. Turn the main battery disconnect switch to the “ON” position.
19. De-aerate the cooling system by topping off the electronics cooling system with fresh coolant while running
pumps with master switch on. Continue to run pumps for ten minutes after full fill to de-aerate. Coolant level
should be checked after the test drive and refilled as necessary.
20. Remove all tools and debris to return coach to service condition.

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ITS: 5591

LABOUR ESTIMATE
Operation
1

ISE Cooling Loop Bypass Removal

Men

Hours

1

1.0

Labour Time
M X HR
1.0

PARTS REQUIRED
Item

Part Number

1

106197

SPEC-HTR HOSE 0.75 ID

Qty.
per
Coach
5.2

2

274935

CLAMP-1.125 DIA TUBE

6

EA

3

6431573

PARKER ¾” CAP, A-LOK®

1

EA

4

218169

COUPLER-1/2PIPEX3/4BARB

1

EA

5

247227

CLAMP-P 1.000

3

EA

Description

Units

Notes

FT

SPECIAL TOOLS REQUIRED
Item

Part Number

Description

Qty.
per
Coach

Notes
Units

NO SPECIAL TOOLS REQUIRED

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ITS: 5591