TIB 42-058: T680/T880/W990 Intermittent Low Coolant Indicator Illumination

Page 1 of 3

Technical Information Bulletin
42-058

Section
Cooling - 42

Subject
T680/T880/W990 Intermittent Low Coolant Indicator Illumination

Release Date
8/23/2019

Condition
The low coolant indicator may illuminate intermittently even though the coolant level is at or slightly above the MIN line on the surge
tank. In some cases, the low coolant indicator may remain illuminated. This condition may be accompanied by a P1560 DTC.
The low coolant indicator may also illuminate when climbing a long hill. By the time the vehicle is stopped and the coolant level is
checked, the coolant level has risen back to or above the MIN line on the surge tank and the low coolant indicator has shut off.

Chassis Affected
All T680, T880, and W990 chassis.

Action
Fix-As-Fail
If a customer comes into your dealership and demonstrates the condition above, proceed with the diagnostics and repairs as described
in the procedures below.

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TIB 42-058: T680/T880/W990 Intermittent Low Coolant Indicator Illumination

Page 2 of 3

Warranty
Through Standard Warranty (includes Extended Warranty) Kenworth will pay for parts at dealer net plus applicable mark-up and labor:
0.3 hours to inspect the harness, and install a fir-tree cable tie assembly if required. File a long-form claim.
If the harness requires repair, use appropriate –xxx time for the repair. File a long-form claim.
Take-Off Parts Disposition: Destroy take-off parts 30 days after claim is paid.
CLAIM CODING
Failure Location:

042-002-009

Work Accomplished:

Failure Type:

700

Responsibility Code:

SRT Code:

042-xxx
Claim Type:
0.3 hours to
inspect harness
and coolant level.
Also includes time
to top-off coolant
level when
possible.

21
01
N/E

Parts
Parts are available from PACCAR Parts.
Quantity

Part Number

Description

1

P16-1006-100

Clip Assembly-Fir tree

1

EC3501 (US)
EC7501 (Canada)

Coolant

Procedure
1.

Inspect the coolant level sensor harness for damage where it is retained by a cable tie to a tab on the surge tank.
NOTE
The routing of this harness is inconsistent. PACCAR Engineering is investigating the optimum harness
routing and repair method. This bulletin will be updated when better information becomes available.

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TIB 42-058: T680/T880/W990 Intermittent Low Coolant Indicator Illumination

2.

Page 3 of 3

If no obvious damage is found, and the cable was retained to the surge tank tab with only a cable tie, replace the cabletie with a fir-tree cable tie assembly. The cable tie only needs to be tight enough to prevent the harness from moving. If
the cable tie is tightened too tightly, it may cause this condition again.
If damage is found, refer to TIB 34-081 for repair guidance.
If no issue was identified in Step 1, the coolant level may be slightly low. If the engine cannot be allowed to cool to ambient
temperature, then provide the customer with 1 gal of premixed coolant.
Slightly low coolant level is the likely cause of the problem. The coolant is drawn down when the engine is under load.
This usually occurs while climbing a long grade.
Confirm that the coolant level is ½ in. (13 mm) above Cold Min Line for a cold engine or ½ in. (13 mm) above the Full
Cold Line for a warm engine. For the cold fill range indicated on the surge tank to be accurate, the coolant must be at
ambient temperature. It can take 12 hours or more for the coolant temperature to cool down to ambient temperature.
Advise the customer to top off the coolant when they check the coolant level as part of their daily maintenance.
Provide the customer with a copy of the coolant fill procedure.

Attachments
Coolant fill procedure

Authored by: OF

Access to PACCAR’s Enterprise Portal is provided as a benefit of doing business with PACCAR. All applications and content accessed
through this system are confidential and proprietary and the property of PACCAR Inc and its suppliers, and must be kept strictly
confidential pursuant to the contract licensing such access. Disclosure, publication, release or distribution of any material found on
PACCAR systems to any person other than employees with a need to know such information is strictly prohibited. All activity on this
system is monitored. If PACCAR suspects or discovers any unauthorized activity, access may be immediately terminated without
prior notification. Violators may be subject to legal action.
© Copyright 2019 PACCAR Inc. All rights reserved. We welcome your feedback on this page. For technical questions or concerns
about this page, please contact the DealerNet Webmaster.

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ADD COOLANT PROCEDURE
How to Add Coolant to the Cooling System

42-056, 42-058

WARNING!
DO NOT remove the surge tank fill cap (1) while the engine is hot. Scalding steam and fluid under
pressure may escape and cause serious burns. Failure to follow this instruction may result in personal
injury or death.
Note: If frequent filling is necessary and there are no visible signs of coolant leaks when the engine
is cold, check for leaks while the engine is operating at normal temperature.
Note: DO NOT remove the pressure cap (2) or use it to add coolant to the surge tank.
Note: DO NOT overfill the cooling system. Excess coolant may result in overflow, loss of antifreeze,
and reduced corrosion protection.
Note: If frequent filling is necessary or there are any signs of coolant leakage, consult a PACCAR
Service dealer.
Check the coolant level before and after each trip. Add coolant as necessary. Coolant may not immediately
appear at the correct level after the radiator is filled. Air may be trapped in the cooling system, which will
affect the coolant level, until the air is purged.
Refer to your Engine Operator’s Manual for coolant mix specifications.
After servicing the cooling system, continue monitoring it for 3-5 days. The coolant level in the surge tank
will lower when air trapped in the cooling system is purged. During each pre-trip inspection you should
inspect recently-serviced components of the cooling system for signs of coolant leaks.

1. Fill cap (service point)
2. Pressure cap (never to be removed)
3. Cold Full line

8/28/2019

42-056, 42-058

Page 1 of 2

How to Add Coolant to the Cooling System

WARNING!
Do not remove the surge tank fill cap when the engine is running or the cooling system is hot. Wait
10 minutes for the cooling system to cool down. If the surge tank is still warm to the touch, cover the
fill cap with a thick cloth to prevent the possibility of scalding and then slowly remove the cap.
Failure to follow this instruction could result in personal injury or death.

CAUTION
Due to thermal expansion the coolant level CANNOT be accurately checked if the coolant is above
ambient temperature or the engine has not completely cooled. The coolant level indicated on a
warmed system will be inaccurate and can lead to low coolant conditions during cold-starts.

1. Turn off the engine and let it cool for a minimum of 10 minutes.
2. If your cooling system is built with an air bleed valve in the upper engine coolant pipe, open the air
bleed valve before filling the surge tank.
3. Close any open coolant drain valves in the lower engine coolant pipe.
4. Remove the surge tank fill cap (1). DO NOT remove the surge tank pressure cap (2).
5. Fill the system with premixed coolant through the surge tank fill port. Pour coolant at a steady rate
until it reaches the “MIN” line in the surge tank. Wait for one minute after adding coolant. If the
coolant level drops, add coolant until it returns to the “MIN” line.
6. Close the air bleed valve that was opened in Step 1.
7. Start the engine and maintain an idle at low rpm.
8. While the engine is idling air will purge from the cooling system through the surge tank's coolant fill
port, which will lower the coolant level in the surge tank. Continue to add coolant to the surge tank
until the coolant level remains approximately 1/2 in. (13 mm) above the "MIN" line. This may take
up to 2 minutes depending upon the outside temperature.
9. Maintain a low idle until the thermostat opens and the operating temperature stabilizes. A sign that
the thermostat has opened is when the upper coolant pipe gets hot on the bottom side indicating
hot coolant is now running through it.
10. Add coolant to the surge tank until the coolant remains 1/2 in. (13 mm) above the "MIN" level.
11. Operate the engine at high idle for 10 minutes. Afterward, add coolant to the surge tank until the
coolant remains 1/2 in. (13 mm) above the "COLD FULL" line.
12. Reinstall the surge tank fill cap.

8/28/2019

42-056, 42-058

Page 2 of 2

42-058 Intermittent Low Coolant Indicator Illumination

Page 1 of 3

42-058

Section
42 - Cooling

Description
Intermittent Low Coolant Indicator Illumination

Release Date
8/23/2019

Introduction
The low coolant indicator may illuminate intermittently even though the coolant level is at or slightly above the MIN line on
the surge tank. In some cases, the low coolant indicator may remain illuminated. This condition may be accompanied by
a P1560 DTC.
The low coolant indicator may also illuminate when climbing a long hill. By the time the vehicle is stopped and the coolant
level is checked, the coolant level has risen back to or above the MIN line on the surge tank and the low coolant indicator
has shut off.

Resolution
Fix-as-Fail
If a customer comes into your dealership and demonstrates the condition above, proceed with the diagnostics and repairs
as described in the procedures below.

Warranty
Through Standard Warranty, Peterbilt will pay for parts at dealer net plus applicable mark-up and labor:
0.3 hours to inspect the harness, and install a fir-tree cable tie assembly if required. File a long-form claim.
If the harness requires repair, use appropriate SRT and/ or non- time for the repair. File a long-form claim.
Take-Off Parts Disposition: Destroy take-off parts 30 days after claim is paid.

For Field...

Enter...

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42-058 Intermittent Low Coolant Indicator Illumination

Failure Location

042-002-009

Failure Type

700

Claim Type

N

Campaign Number

42-058

Page 2 of 3

042-058
Labor

0.3 hours to inspect the harness and
coolant level. Also includes time to top-off
coolant level when required.

Parts

Quantity

Part Number

1

P16-1006-100

Description
Clip Assembly-Fir Tree

EC3501 (US)
1

Coolant
EC7501 (Canada)

Procedure
1. Inspect the coolant level sensor harness for damage where it is attached by a cable tie to a tab on the surge tank.

If no obvious damage is found, and the cable was attached to the surge tank tab with only a cable tie,
replace the cable-tie with a fir-tree cable tie assembly. The cable tie only needs to be tight enough to
prevent the harness from moving. If the cable tie is tightened too tightly, it may cause this condition to
reoccur.

https://eportal-auth.paccar.com/dealer/uspb/en/service/vehiclebulletins/vehiclefieldservice/P... 9/3/2019

42-058 Intermittent Low Coolant Indicator Illumination

Page 3 of 3

If harness damage is found, refer to 34-066 for repair guidance.
2. If no issue was identified in Step 1, the coolant level may be slightly low. If the engine cannot be allowed to cool to
ambient temperature, then provide the customer with 1 gal of premixed coolant.
Slightly low coolant level is the likely cause of the problem. The coolant is drawn down when the engine is
under load. This usually occurs while climbing a long grade.
Confirm that the coolant level is ½ in. (13 mm) above Cold Min Line for a cold engine or ½ in. (13 mm)
above the Full Cold Line for a warm engine. For the cold fill range indicated on the surge tank to be
accurate, the coolant must be at ambient temperature. It can take 12 hours or more for the coolant
temperature to cool down to ambient temperature.
Advise the customer to top off the coolant when they check the coolant level as part of their daily
maintenance.
Provide the customer with a copy of the coolant fill procedure.

Attachments
Coolant Fill Procedure

Authored by: RP

Access to PACCAR’s Enterprise Portal is provided as a benefit of doing business with PACCAR. All applications and content accessed
through this system are confidential and proprietary and the property of PACCAR Inc and its suppliers, and must be kept strictly
confidential pursuant to the contract licensing such access. Disclosure, publication, release or distribution of any material found on
PACCAR systems to any person other than employees with a need to know such information is strictly prohibited. All activity on this
system is monitored. If PACCAR suspects or discovers any unauthorized activity, access may be immediately terminated without
prior notification. Violators may be subject to legal action.
© Copyright 2019 PACCAR Inc. All rights reserved. We welcome your feedback on this page. For technical questions or concerns
about this page, please contact the DealerNet Webmaster.

https://eportal-auth.paccar.com/dealer/uspb/en/service/vehiclebulletins/vehiclefieldservice/P... 9/3/2019