This is easy to do, but with a little information it will make it easier and more straight forward. My truck is a 1990....it seems that this should be the same on c1500's from 1988* to 1994*. What you need. 1/2" wrench/socket 9/16" and 1/2" flare wrench for brake lines. 5/16" male x 1/4" female brake line adapter fitting. ie, EDELMANN #258450 (available at O'reilly auto parts.....about $5.) 15 minutes + time to bleed your rear brakes. The Master cylinder has the fluid reservoir on top. The isolation dump valve is below it (to be removed). To the right of that is the proportioning valve (gotta keep that). Attached to the proportioning valve is the control box (black plastic with wired connectors). Lets Start off by removing the control box. First, remove the connectors from the rear. The top one is part of the vehicle harness. The lower plug connects to the other part that will be removed. Then, jiggle the box and pull towards the front of vehicle. Should slip off. now we should be looking like this.... Next, disconnect the two lines from the bottom of the isolation/dump valve...one of the lines is very short and connects to the proportioning valve. Disconnect from the proportioning valve as well. After those are removed, simply remove the two bolts (1/2" socket/wrench) from the the top of the valve where it attaches to the bracket. With all that crap out of the way, its easy to see what we have left to do, which is not much. I bought this fitting at Oreilly auto parts for $5.49 plus tax. It will allow you to use the existing brake line and screw into the proportioning valve. It is EDELMANN 258450. The male threads are 5/16" and the female are 1/4". This is a brake fitting. You can probably find something similar but those are the right dimensions. Screw that in the bottom of the proportioning valve. I used some teflon tape for good measure. The use a little bending to reposition the line and tighten it up. And that's it! Bleed your Rear brakes, hopefully you have will better pedal feel. Mine have improved greatly, but still feels a little spongey for my liking.