167-B2306-1

SERVICE BULLETIN
L-SERIES REDUCED OR INTERMITTENT A/C
PERFORMANCE
SUPERSEDES TT-22-012
GROUP: 0-GENERAL
SB NO : 23-002
DATE: 6/7/2023
REF HMM TSB-001-23
SUBJECT VEHICLES:
2022-2023 Model Year L-Series Trucks Equipped with a
Cummins B6.7 Engine, assembled at the Mineral Wells, West
Virginia, USA assembly plant before May 9, 2022.
Note:
This technical service bulletin is provided as technical
information and is not authorization for a warrantable repair.
OVERVIEW:
Some trucks built prior to May 9, 2022 may experience
reduced or intermittent cooling performance from the air
conditioning system. If a subject vehicle exhibits this condition,
it’s likely that the refrigerant was overcharged during vehicle
assembly. This procedure provides instructions for proper
recovery and recharge of the refrigerant system and
appropriate warranty claim application information.
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.
REPAIR PROCEDURE:
NOTICE: During this repair procedure, make certain
that you follow all of the operating instructions and
warnings called out for the specific R-134 Refrigerant
Recovery, Recycle and Recharge Machine being used.
1. Connect an approved and certified R-134 Refrigerant
Recovery, Recycle and Recharge Machine to the vehicle’s air
condition system. Service ports are located near the engine air
filter housing.
2. Recover the R-134 refrigerant from the vehicle’s air
conditioning system. Refer to the R-134 Refrigerant
Recovery, Recycle and Recharge manual of the machine
being used.
3. Once the R-134 refrigerant has been recovered, vacuum the
vehicle’s air conditioning system for 10 minutes. Refer to the
R-134 Refrigerant Recovery, Recycle and Recharge
manual of the machine being used.
4. Once the 10 minute vacuum has been completed, charge
the vehicle’s air conditioning system with 450 grams of
refrigerant including any oil that may have been removed
during the refrigerant recovery or vacuum step. Refer to the R134 Refrigerant Recovery, Recycle and Recharge manual
of the machine being used.
Refrigerant: HFC 134a
Air Conditioning Compressor Oil: ND-OIL 8
5. Once the proper R-134 refrigerant charge has been added
to the vehicle’s air conditioning system, follow the R-134
Refrigerant Recovery, Recycle and Recharge Machine’s
manufacturer instructions for disconnecting the machine’s high
side and low side service lines from the vehicle air conditioning
system. Ensure the high side and low side service port caps
are reinstalled back onto the vehicles service ports
FINAL INSPECTION:
To complete this TSB review and thoroughly inspect the
vehicle to confirm the following:

The vehicles air conditioning system has been charged
with the correct amount of R-134 refrigerant.

The low side and high side port caps are installed.
CLAIM APPLICATION:
•
Reimbursable in accordance within the terms and policies
of the Hino limited warranties.
Air Conditioning Refrigerant Recovery and Recharge
a)
Labor charge: 1.0 Hour
b)
Warranty code: 71053
c)
Trouble code: 40
d)
Operation code: 71850AOT
e)
Original failed part: 9999999999