SERVICE BULLETIN
22-23 MY L-SERIES COOLANT DEGAS
BOTTLE SUPERSESSION
GROUP: 0-GENERAL
SB NO : 24-002
DATE: 2/29/2024
REF : HMM-240219-F1

SUBJECT VEHICLES:
2022 and 2023 model year Hino L-Series Conventional vehicles
equipped with a Cummins B6.7 engine that were assembled at the
Mineral Wells, West Virginia USA assembly plant.
Note:
This technical service bulletin is provided as technical information
and is not authorization for a warrantable repair.
OVERVIEW:
For 2022 model year and 2023 model year L-Series Conventional
trucks built before March 25, 2022, the coolant degas bottle service
part, (Hino P/N S16F0E0470), has been discontinued and
superseded with (Hino P/N S16F0E0480). If the coolant degas
bottle is damaged and requires replacement, this Technical Service
Bulletin (TSB) contains an inspection procedure to confirm which
coolant degas bottle is equipped on the vehicle and then a repair
procedure which contains directions for installing the updated
coolant degas bottle.
BEFORE YOU BEGIN:
-

Read and understand all instructions and procedures before you
begin the work.

-

Read and follow all WARNINGS and NOTICES set forth in this
publication.

-

Park the vehicle on a flat, level and solid surface.

-

Place the gear shift lever in "Neutral" or "Park".

-

Apply the parking brake firmly and confirm parking brake
activation.

-

Place wheel chocks in front of and behind all the
wheels to prevent the vehicle from moving.

VEHICLE PREPARATION:
1. Park the vehicle on a flat, level and solid surface.

2. Confirm the engine is stopped, the ignition switch is in the off
(LOCK) position, and the key is removed.

3. Apply the parking brake.

4. Chock all of the wheels.

PARTS:

INSPECTION PROCEDURE:
1. Locate the coolant level sensor mounted in the coolant degas
bottle. Is the coolant level sensor located to the left of the coolant
degas bottle centerline?
NO – This is the revised coolant degas bottle. Disregard this TSB, it
does not apply to this vehicle.
YES – This is the discontinued coolant degas bottle, as shown in
the photograph to the right. Proceed to the REPAIR PROCEDURE

REPAIR PROCEDURE:
1. Allow the engine and cooling system to cool down to ambient
temperature. Remove the engine coolant fill cap from the coolant
degas bottle. Open the radiator drain valve and drain the coolant
into a suitable container until the coolant degas bottle is empty.
Close the radiator drain valve when the coolant degas bottle is
empty.

WARNING: Do not loosen or remove the coolant fill cap or attempt
to drain the cooling system until the coolant and engine have cooled
to ambient temperature. Loosening or removing the coolant fill cap
or draining the cooling system prior to the cooling system cooling
down could cause severe personal injury due to scalding.

2. Disconnect the overflow hose at the coolant degas bottle and
then the coolant level sensor connector. Remove and discard the 2
wiring harness retainers, and single zip tie.

3. Release the 2 air bleed hose clamps and disconnect both air
bleed hoses from the coolant degas bottle. Release the coolant
hose clamp and disconnect the coolant hose from the pipe.

4. Remove the 4 fasteners securing the coolant degas bottle, retain
the fasteners. Remove the coolant degas bottle, coolant hose and
coolant hose clamp from the vehicle and discard.
NOTICE: When removing the degas bottle, there is still a coolant
hose and clamp attached to the coolant degas bottle on the right
underside. These will be discarded.

5. Inspect the coolant degas bottle that was just removed. If the old
degas bottle contains a coolant attention label, ensure a new
attention label is affixed to the new coolant degas bottle before
installing the coolant degas bottle to the vehicle.

6. Using the new coolant degas bottle, install the new coolant hose
onto the coolant degas bottle. Position the white alignment mark on
the coolant hose with the raised alignment mark on the coolant
degas bottle. Position the 2 coolant hose clamps as shown in the
photograph below.
NOTICE: In the photograph below, the raised alignment mark on
the coolant degas bottle has been highlighted yellow for your
reference.

7. Install the new coolant degas bottle using the four fasteners
previously removed. Tightened to the specified torque.
Specified Torque: 16 ft-lb (22 Nm)

8. Connect the 2 air bleed hoses, reposition and engage the 2 air
bleed hose clamps. Connect the coolant hose onto the pipe and
reposition and engage the coolant hose clamp.

9. Position the zip tie around the wiring harness and coolant hose,
approximately 2 inches (50mm) below the original location. Do not
fully tighten the zip tie during Step 9.

10. Connect the coolant level sensor connector. Clip in the wiring
harness retainer onto the radiator support in position B. Wrap the
zip tie potion of the wiring harness retainer around the wiring
harness but do not tighten it at this time. Remove most of the slack
of the wiring harness between the coolant level sensor and wiring
harness retainer and then tighten the zip tie portion of the retain at
position B. Now tighten the zip tie at the coolant hose. Reconfirm
the wiring harness will not contact the fan or that the wiring harness
is pulled too tight.
NOTICE: If the wiring harness is pulled too tight between the
coolant level sensor and wiring harness retainer, damage may
occur to the harness, or related connector terminals.
NOTICE: Be sure the harness does not contact the radiator cooling
fan or damage will occur.

11. Slowly refill the cooling system and securely install the degas
bottle cap to the degas bottle. Start the engine and run the engine
until the engine and cooling system are at operating temperature.
Shut the engine off and remove the ignition key.
NOTICE: During vehicle manufacturing, one of two different types
of engine coolant could have been used. To ensure the correct
replacement engine coolant is added to the cooling system, inspect
the degas bottle for an ATTENTION label. If an ATTENTION label is
affixed to the coolant degas bottle, then use the Optional Cooling
System Fluid Fill to top-off the cooling system. If no label is found,
then use the Standard Cooling System Fluid Fill.
Standard Cooling System Fluid Fill
Fleetguard ES Compleat OAT EG 50/50
Optional Cooling System Fluid Fill
Shell Rotella ELC Nitrate Free 50/50

12. Proceed to the FINAL INSPECTION.

FINAL INSPECTION:
To complete this technical service bulletin, review the bulletin and
confirm the following:
• Inspect for coolant leaks.
• Make certain the correct coolant was used and that the coolant
level is full.
• Make certain that if the old coolant degas bottle had an
Attention Label affixed to it, a new Attention Label was
affixed to the newly installed coolant degas bottle.
• Wiring harness is correctly routed and not contacting the
cooling fan.

CLAIM APPLICATION:
•

Reimbursable in accordance within the terms and policies of
the Hino limited warranties.

Header Tank Installation:
a) Labor charge: 0.5 Hours
b) Warranty code: 13210
c) Trouble code: 12
d) Operation code: 13201BRE
e) Original failed part: S16F0E0470