Are you having cluth problems at the same time? E-brake issues?
All three of these pieces are using the same fluid reservoir. My issue came from seeing the e-Brake light come on while driving, and then go off. Then it stayed on constant the next day, and when I went to leave the office I had no clutch. Ended up being the master->slave cylinder connection tore right out of the master. Good thing is it was a TSB, and I got it fixed free. =)
E1