Brake Fluid question?

I just put new rear calipers, hoses, pads and rotors on my 87 and i am wondering how much brake fluid others had removed when they flushed there brakes system. I removed about 100 oz to get new clean fluid in the system. (including fronts)

I was able to get remaned rear calipers for $63.50 each (unloaded) with mounting brackets. 3 rear brake hoses for $65.50 and pads for $22.00. My old original calipers would no longer slide on the pins and I wore one shoe down to nothing. Was putting off changing the brakes until i got every last bit of brakes out of them. Not bad for rear brakes complete for about $225.00

The local NAPA store failed to get me my calipers after 5 days so I went to a local Brake store to get them.

Next is new mufflers and tail pipes. Sure glad I got lifetime Midas mufflers on the car. Gonna use my "Free Replacement" soon.

I flush my brake system every 2 years, and usually have to put 1 1/2 to 2 quarts thru it to get the fluid looking like new. Keep in mind that since I flush it every 2 years, it isnt that horrible in the first place.