SB09-J-002F

BULLETIN NUMBER:
SB09-J-002F
IMPORTANT SERVICE
INFORMATION FOR:
 SERVICE MANAGER
 SERVICE ADVISOR
 TECHNICIAN
 PARTS DEPARTMENT
 WARRANTY PERSONNEL
ISSUE DATE:
DECEMBER 2020
GROUP:
ENGINE
EGR COOLER PRESSURE TESTER TO DIAGNOSE ISUZU
DIESEL ENGINE EGR COOLER LEAKS
AFFECTED VEHICLES

2005MY- Current Isuzu N-Series

2011-2018MY NPR Stripped Chassis (Reach)

2005-2010MY GMC and Chevrolet W-Series

2007i-2009MY Isuzu F-Series

2018MY-Current Isuzu F-Series

2007i-2009MY GMC and Chevrolet T and C-Series 6HK1
Equipped with Diesel Engines with an EGR Cooler
This bulletin supersedes SB09-J-002E. This bulletin is being revised to update
model years and content. Please discard previous bulletin SB09-J-002E.
INFORMATION
An EGR cooler tester was provided to dealers in June 2009 to diagnose EGR cooler leaks
on all Isuzu diesel engines equipped with an EGR cooler. This tester consists of a
pressure regulator assembly J-46091-1 and adapters EN-48974-5, EN-48974-15, and
EN-48974-30.
Important: Leaks from the EGR cooler may allow coolant to pass through the exhaust
system and enter the combustion chambers. Failure to inspect the EGR cooler for leaks
may lead to a misdiagnosis for engine coolant in the combustion chamber.
Important: Leaks from the EGR cooler may allow exhaust gas air to pass to the engine
coolant passage within the EGR cooler. Failure to inspect the EGR cooler for leaks may
lead to a misdiagnosis of air in the engine cooling system.
EGR Cooler Pressure Tester
J-46091-1 – EGR Cooler Tester Pressure Regulator Assembly
EN-48974-5 – EGR Cooler Tester Adapter (5/8 inch for 2005-2007 5.2L,
2007-2009 7.8L, 2011-2018 3.0L)
EN-48974-15 – EGR Cooler Tester Adapter (17 mm for 2007i-2010 5.2L)
EN-48974-30 – EGR Cooler Tester Adapter (1 inch for 2011-Current 5.2L)
SERVICE PROCEDURE
EGR Cooler Testing
1. Partially drain the engine coolant and remove the EGR cooler hoses.
2. With the cooler on the engine, install the end cap and clamp of EN-48974 (EGR
cooler tester adapter) on one of the EGR cooler hose barbs and install the pressure
tester adapter hose and clamp to the other EGR cooler hose barb.
3. Back off the regulator on the J-46091-1 (EGR cooler pressure regulator assembly)
by turning the knob counterclockwise until it stops.
4. Connect J-46091-1 to EN-48974, and connect 90 PSI shop air to J-46091-1.
5. Open the shutoff valve, and then slowly turn the regulator on J-46091-1 clockwise
until the gauge reads 30 psi.
6. Shut off the valve on J-46091-1 and monitor the gauge for leak down. Remove the
EGR cooler if it does not hold pressure.
7. If the EGR cooler does not hold pressure, redo Steps 5 and 6 with the EGR cooler
submerged in very warm water (which allows the EGR cooler to expand). After
placing the EGR cooler under very warm water, shake and rotate the cooler for
approximately 1 minute to ensure all air bubbles escape from the exhaust gas
passage before testing. With the pressure set to 30 psi watch for air bubbles.
Watch for at least 1 minute. This is done to ensure the EGR cooler is leaking and
not the EGR cooler tester.
Note: Not removing this trapped air may result in missed diagnosis.
Rotate Cooler to release trapped air
Shake Cooler to release trapped air