GM Service Manual Online
For 1990-2009 cars only

Notice: Antifreeze will deteriorate the Viton O-ring seals and the glue used to bond the clutch material to the pressure plate. Both conditions may cause transaxle damage.

Perform the following steps if the transmission oil cooler has developed a leak, allowing engine coolant to enter the transmission:

  1. Because the coolant will attack the seal material causing leakage, disassemble the transmission and replace all rubber type seals.
  2. Because the facing material may become separated from the steel center portion, replace the composition-faced clutch plate assemblies.
  3. Replace all nylon parts including washers.
  4. Replace the torque converter.
  5. Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.
  6. Flush the cooler lines after you have properly repaired or replaced the transmission cooler.