So I'm having some brake issues. I have 2 master cylinders (stock one and a brand new Willwood unit) and they both have same symptoms. Not alot of pedal and when we crank it to put some vaccum in the booster it gets really soft and is very very slow to come back up. All rubber lines have been replaced with braided stainless and we have triple checked everywhere for leaks so I'm thinkin it's either the abs unit (probably gonna just tear it off anyway), or the proportioning valve. Any ideas...