Re: OK? could it be in the abs??
ABS is unlikely the culprit. Poor rebuilt parts would be my answer also. Never get the cheapest available. Under the brake fluid reservoir (I believe) you should have four lines running out of that, one line to each wheel. I'd get a proper brake fluid flush done at a reputable place to make sure there's no debris that just happens to clog that particular line. Never know.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!