have a 69 dart. my propotionating valve has 4 lines coming out and going to all 4 brakes. so i put my line lock in after the master on the front brake line coming out,it is brand new from jeggs. you can hear the sylonoid actuating when you press the button but it will not lock the front brakes. i have never seen a prop valve like this with a line comming out for all four brakesshould i go after the prop valve and try to tee in?