Help!

I was working on something else in the rear when I accidentally leaned
on and broke off the plastic hose connection on the assembly below the
rear bleeder valve.a little coolant leaked out already, but I am afraid
to see what would happen if I actually started the motor with it like
this.

Question.

Until I can get this replacement part (please let it be available) what
is my workaround? Can I plug the other end of the hose that leads to the
expansion tank? Will coolant still leak out with that bleeder valve
closed?? Am I hosed!??!?!?!

Dave

85 1.9