| Subject: | Clutch Hydraulic System -- New Service/Owner Maintenance Information |
| Models: | 2005-2009 Chevrolet Corvette (Including Z06 and ZR1) |
| with Tremec 6-Speed Manual Transmission (RPOs MM6, MZ6, MH3) |
This bulletin is being revised to update the models to 2009. Please discard Corporate Bulletin Number 07-07-31-001 (Section 07 -- Transmission).
This bulletin is being issued to provide dealers with additional information on servicing the clutch hydraulic system. Please also advise customers of this new maintenance information.
Some cases have been found where the vehicle's clutch hydraulic system was contaminated with water. Higher than expected levels of water in the clutch fluid greater than 2% may cause the clutch fluid to boil. The presence of water in the fluid lowers the
boiling point significantly; when this occurs, the driver may lose customary clutch pedal feel and performance.
To eliminate the opportunity for moisture to enter the clutch hydraulic system:
| • | The clutch fluid level inspection should be a VISUAL inspection only. Look through the transparent reservoir and observe the fluid level. Avoid removing the cap. DO NOT remove the cap just to top-off clutch fluid. Leave the system closed and sealed.
During PDI inspection or routine service, the cap should not be opened for just an inspection. |
| • | Open containers of DOT 4 clutch fluid have a two week shelf life. DO NOT use fluid if the container opening date is unknown or older than two weeks. DO NOT mix or re-use old fluid. Current service information already covers the issue of reuse. |
| • | To provide the best clutch operation, it is recommended that the owner change the clutch fluid every two years. Please flush and replace with P/N 88958860 (P/N 88901244 in Canada) or equivalent DOT 4. |
