There is only one reservoir for both the rear and front. If the front is working so will the back. There is only one reservoir for both the rear and front. If the front is working so will the back.
On a 2001 Ford Focus : The brake fluid reservoir is used for the brake and clutch systems
On a 2001 Ford Focus : The thread on cap on your engine coolant reservoir is the pressure cap / radiator cap
It is locater behing the drivers side fender! That's it.
See answer on "How do you change the front brake pads on a 2001 Ford Focus?" for a description of the location of the resivoir. The answer to this exact location is at the bottom of that answer.
The 2001 Ford Focus takes 22" drivers side and 19" passenger side replacement windshield wiper blades. (If applicable, the rear wiper blade on the hatchback is 14" and the rear wiper blade on the wagon is a 10" or 11"). See sources and related links below for more information.
How do you change the wiper control module on a 2006 Ford Focus
The thread on cap on your engine coolant reservoir is the pressure cap / radiator cap
REmove the inner wheel well liner and you'll be staring right at it.
In a 2003 Ford Focus : The engine coolant reservoir is on the passenger side of the engine compartment ( it has a thread on pressure cap )
there is a 10 mm bolt right underneath the coolant reservoir an a clip securing it down in the back remove both of those and it will come out
I do not see a rear wiper blade listed for a 2008 Ford Focus. If there is one on there, it must be a special Ford-only wiper (which is rare for Ford - they normally go with universal wipers). I do see that 2000-2007 Ford Focus has a rear wiper listed for both the hatchback and wagon. So, possibly you have the year wrong? If so, the wiper blade videos for hook-end wiper arms will show you how to change the rear (as well as front) wiper blades.
The 2001 Ford Focus has 16 valves.