where do you add brake fluid in a 1992 volvo 240

Here it is:
http://s250.photobucket.com/albums/gg253/jbrown122/?action=view¤t=volvo240brakefluid.jpg

drivers side of car,under hood, up by the cowl u will see a round vacume chamber with a 3/8 inch hose going to the intake manifold.
the master cylinder is bolted to the center of this & the reservoir is located on top of that [it is made of translucent white plastic] the cap is embossed with instruction to use D.O.T.-4 brake fluid only.
note: while the only fluid allowed is D.O.T.-4 [there r several brands & colors of fluid available] castrol is amber in color,while a.t.e. is blue [these r just vegetable dyes & will not affect performance if mixed.
use of D.O.T.- 3 fluid in an emergency is ok but the system should be flushed at the earliest opportunity & replaced with the D.O.T.-4 fluid as specified by volvo [while compatible with the rubber parts in the hydraulic system, D.O.T.-3 fluid has a lower boiling point & is more apt to absorb water than D.O.T.-4 fluid.although both fluids r hygroscopic [will absorb water from the atmosphere] this is why only fluid from a freshly opened sealed container should be used.
hope this helps.
one last note if anything other than brake fluid is introduced into system every piece of the hydraulic system will have to be replaced.