Transmission Fluid Cooler Flushing and Flow Test: Notes

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The J 45096 - Automatic Transmission Oil Cooler Flush and Flow Test Tool can be used to flush the transmission oil cooler system on an Allison equipped vehicle, but the flow meter should not be utilized.

GM studies indicate that plugged or restricted transmission oil coolers and pipes cause insufficient transmission lubrication and elevated operating temperatures which can lead to premature transmission wear-out. Many cases could have been prevented by following published procedures for transmission oil cooler flushing and flow checking. This procedure includes flushing and flow checking the auxiliary transmission oil cooler, if equipped. GM requires that transmission oil cooler flushing and flow checking be performed whenever a transmission is removed from the vehicle for service within warranty, including:

Goodwrench SRTA
Major overhaul
Torque converter replacement
Oil pump replacement

Only GM Goodwrench DEXRON® VI automatic transmission fluid should be used when doing warranty repair on GM transmissions.

Tools Required

J 35944-A Transmission Oil Cooler and Line Flusher
J 35944-22 Transmission Oil Cooler Flushing Fluid
J-44835-1 Transmission Oil Cooler Flusher Adapters
Measuring cup
Funnel
Water supply - hot water recommended
Water hose at least 16 mm (5/8 in) ID
Shop air supply - with water/oil filters, regulator and pressure gage
Air chuck with clip, if available
Oil drain container
Minimum 19 L (5 gallon) pail or similar container with lid
Eye protection
Rubber gloves