| Subject: | Automatic Transmission Oil Cooler Flushing and Flow Testing |
| Models: | 1999-2007 Chevrolet W-Series Medium Duty Tilt Cab Models |
| 1999-2007 GMC W-Series Medium Duty Tilt Cab Models |
| 1999-2007 Isuzu N-Series Commercial Models |
| with 4HE1 or 4HK1 Diesel Engine and AISIN A450-43LE Automatic Transmission or |
| 5.7L or 6.0L Gas Engine (VINs R, U -- RPOs L31, LQ4) and 4L80-E Automatic Transmission |
This bulletin is being revised to add model years and change warranty information. Please discard Corporate Bulletin Number 03-07-30-060A (Section 07 -- Transmission/Transaxle).
Whenever an AISIN or 4L80-E automatic transmission is repaired or replaced, the transmission oil cooler and lines MUST be flushed and flow tested prior to reassembly.
The oil cooler and lines must be flushed and flow tested using the following Kent-Moore special tools:
| • | J 35944-A - Transmission Oil Cooler Flusher |
| • | DT 46718 - Transmission Filter By-Pass Adapter |
| • | J 35944-18 - Transmission Oil Cooler Flusher Adapters |
| • | J 35944-22 - Flushing Fluid |
Follow all the directions and precautions listed in the published Service Information for use of J 35944-A.
There are some Medium Duty dealers that may have a light duty truck franchise. Most of these dealers may be using the J 45096 Transflow Transmission Oil Cooler Flow Tester and Flusher. J 39544-18 Transmission Oil Cooler Flusher Adapters are
available that can be used with the J 45096 flusher. Follow the instructions supplied with the adapters. An example instruction card is shown below.
Warranty Information
For vehicles repaired under warranty, use the appropriate labor operation.
Use the flush time allowance with each appropriate operation. Flush time has been added to appropriate operations.
Use $6.50 in NPN for flushing fluid reimbursement.
All of the following steps MUST be performed during R&R of an Aisin transmission.
- Flush and flow test the cooler and cooler lines.
- Perform the TPS Relearn procedure (1999-2004 MY Aisin Transmission).
- Complete the Core Return Form.
- Drain the fluid from the Core.
