Some 2010 Toyota Prius models may produce a slight coolant leak from underneath the vehicle. One possible cause, Toyota said, is an insufficiently tightened inverter coolant drain plug.
To check things out, put the hybrid vehicle on a lift and remove the front spoiler cover, followed by the engine undercover. You should see the coolant drain plug at the bottom of the transaxle, as shown in the illustration.
If you notice coolant seeping from or around the plug, clean the area with a shop rag, then retighten the drain plug to 35 ft-lbs. (the plug doesn't have to be loosened or removed to perform the procedure).
To complete the fix, reinstall the engine undercover and front spoiler cover, lower the vehicle and fill the inverter's reserve tank with the proper amount of coolant.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via email at [email protected].