D O T ( 3 ) brake fluid
Brake fluid is an extremely important component of vehicle maintenance. For a 2007 Impala, there are several brake fluids to choose from. The brake fluid will depend on the specific needs for your car. The factory brake fluid is a DOT 4 fluid.
D O T ( 3 ) brake fluid
DOT ( 3 ) brake fluid in North America
any brake fluid that has a DOT 3 rating will work
The clutch uses DOT 3 or 4 brake fluid, and shares the reservoir with the brake system. The brake fluid reservoir is the same as the clutch fluid reservoir.
According to the 2007 Ford Edge Owner Guide : ( DOT 3 brake fluid meeting Ford specification WSS-M6C62-A )
Open the hood, by the fire wall in the back on the drivers side is the Brake fluid reservoir, unscrew the cap and fill it with the appropriate DOT brake fluid to the line.
DOT 3
If, as you say, it needs doing then it should be done as soon as possible. Brake fluid seldom needs changing though it does degenerate over time, mainly by absorbing moisture. The precise detail will be in your manual. The fluid reservoir needs checking topping up occasionally and certainly will require it after a brake pad change.
A 2007 Ford Explorer would have 4 wheel ABS ( Anti-lock Brake System )
Dot-4
DOT 3