I have most of the OEM parts to switch my 66 Skylark to the GM factory discs in front. It's a power brake car from the factory and I have 15" Buick rallys on it. I have a couple of questions: 1. I plan on using a standard disc/drum prop valve. Right now the car has a distribution block on the frame below the brake booster/master. Do I replace this distribution block with the prop valve (is it a direct swap or do I need to modify lines)? I was considering having the prop valve mounted below the master but then need to do something about the lines. Hoping for a little clarification here on brake lines and prop valve for conversion. 2. Can I just purchase a dual master cylinder designed for disc/drum and bolt it to my existing booster? Or do I need to change the booster as well? Just trying to keep the cost down by using what I have as well as purchasing the correct parts needed. Thanks, Rick
I can't guarantee my answers are 100% correct but you are converting from single line to dual line brakes, right? We converted a buddy's 66 Chevelle from single line manual drums to power dual master and front discs and everything bolted up though we have a whole junk Monte Carlo to rob parts off of. The old distribution block will probably come out and be replaced with your intended prop valve. Be sure to get one for a 1971-ish A-body. It will be your best bet at getting it hooked up with as little custom lines as possible. Later ones do not have the same brake light switch connection. You may have to rebend or get new lines for the front wheels from the old distribution block. The rear line MIGHT connect to the new proportioning valve or it might need to be rebent slightly and a different flare nut used. The brackets that hold the flex line at the frame have a different hole than the disc hoses. Not a huge obstacle but something to be aware of if you have trouble with that clip to secure them. Yes, you can mount a dual master to your existing brake booster. Be sure to note how the old master is configured. There is a deep and a shallow rod as far as I know. Someone else might chime in. Some come with a deep hole and a slug to take up the space if you have a short rod. Someone like Right Stuff or Inline Tube should have a conversion kit with everything to make it look factory. If you have some of it from a donor, they should have any of the pieces you need, from spindles to lines.
Thank you for the info Greg! I had a feeling I would have to mess with the lines a bit depending on where I mount the prop valve. The only parts I need to complete the conversion are the master and prop valve and possibly brake lines. Anyone use Inline Tube for brake lines? Do they fit correctly on Buicks or is there some tweaking that needs to take place?
I used Inline Tube when I converted my 71 from 4-drum to front disc. They had the lines that worked pretty well from the master to the prop valve. I was able to tweak my block to front wheel hard lines to work with the flex lines and I had the proper mounting tabs from the donor car.
