hiya.....im tryin to sort out th back brakes on my 1999 merc. they dont do anything and there is no fluid coming out wen i try to bleed them. the front are fine tho. could this be a abs pump problem? please help xxx

 

Probably a master cylinder problem - loosen the fiting at the master for the rear brakes, push on the pedal.
If seems ok, then at the pump.

If you get flow there, then it is possible your rear brake hoses have collapsed. I've never seen this, but I often hear about it happening.