Ford 2003 Mustang Workshop Manual page 1647

15. CAUTION: Do not use metal scrapers, wire brushes, power abrasive discs or other
abrasive means to clean the sealing surfaces. These tools cause scratches and gouges
which make leak paths. Use a plastic scraping tool to remove all traces of old sealant.
Clean and inspect the sealing surfaces and the valve cover gaskets. If necessary, install new
gaskets. Make sure the gaskets are correctly seated on the valve cover.
Installation
All vehicles
1. NOTE: If the valve cover is not secured within four minutes, the sealant must be removed and
the sealing area cleaned with metal surface cleaner. Allow to dry until there is no sign of
wetness, or four minutes, whichever is longer. Failure to follow this procedure can result in
future oil leakage.
Apply silicone gasket and sealant to areas shown.
2. Install the LH valve cover and loosely install the bolts.