2001 Mitsubishi Montero • 200,000 miles

I have a 2001 mitsubishi montero xls not a sport. I replaced the brake relay switch and the accumulator because the anti lock buzzer and light is stuck on. After replacing these parts I thought his would fix my problem because once befor it did about 2 years ago. But it did not. So I tried to bleed the brakes to see if any air was in the lines. I could get fluid to the front lines but no through the back lines. I even tried to bleed at the master cylinder on the front lines would bleed but not the back. Is the a sing of a bad hydro pump?
October 30, 2012.

If the front line of master cylinder I working and rear is not, you either have a failed master cylinder or the brake booster push rod have insufficient clearance (free play)

Oct 31, 2012.