Why would dashboard brake warning light stay lit on 1999 Altima even though master cylinder fluid level is full?
That light may indicate there is a problem with your ABS system.
I do not own an Altima but some dashes have an ABS light and some
don't. If yours has an ABS light in the dash then please disregard
my reply. The only other reason a brake light may be on is if the
piston in the master cylinder goes down too far and hits an
electrical conection that tells you you may have fluid loss such as
a caliper leaking but you said the brake fluid is full unless your
master cylinder is failing