Ford 2003 Mustang Workshop Manual page 632

is located on the front of the power brake booster.
is installed separately; (install a new grommet when installing a new check valve).
is positioned between the power brake booster and the power brake booster hose.
closes when the engine is turned off.
in the closed position, traps engine vacuum in the power brake booster
retains vacuum to provide several power assisted brake applications with the engine off.
Item Part Number
1 2140
2 2005
Description
Master cylinder
Power brake booster