coolant leak

[cwilson jr]

i just got my a/c running for the first time and had my gauges hooked up checking pressure.  they were holding steady for a few minutes when all of a sudden the reading went crazy high and was possibly jumping irradically, (don't remember exactly due to the next thing getting my focus) and i noticed fluid spewing up.  turns out my lower rad. hose blew.

why would this affect my a/c?
the coolant is not even coolant,  i am leaking pure brown fluid.  how bad is this?

[74 C-10 Shorty]

That's rusty water as in no coolant, needs a good flushing of the system.