Brake bleeding question

[adt123nvegas]

Hi all. First time poster here. I recently purchased a 1992 Bronco. It has been negected a bit, but all the basics were there and the price was great. When I got it I knew the brakes felt real spongy and figured they only needed to be bled, as they worked fine with three pumps. Yesterday, a friend and I were looking it over and doing routine maintenance (oil change, plugs, wires, yada yada yada) and I was trying to bleed the brakes. The front brakes were fine, so I moved to the rear. We went through almost two reservoirs of fluid and it still wouldnt bleed all the air out. I was still getting air out of the lines, and it still had the same spongy pedal. My friend thinks its the master cylinder, I am not so sure. There are no leaks in the lines anywhere (it doesnt leak fluid). Any ideas? Thanks in advance for any and all advice.

 

[steechfinger]

did you bleed the prpoprtioning valve?

 

[firelt90bronco]

The master cylinder in my 90 went and that was the reason for the spongy pedal. Look around the base of the master cylinder and on the booster for a rusty area. The cylinder isn't hard to replace just bench bleed it before and don't put any stress on the lines going to it.