Recently a friend had a new front brake hose come apart at the crimp causing a massive leak and loss of front brakes. Lucky for him it wasn't a panic stop situation and he has a dual master cylinder brake sytem. Even though I have replaced all of my lines with SS lines from Inline Tube, it was still in the back of my mind that something very bad could happen should I lose system pessure in my single pot master cylindr brake system. Therfore I ecided to cange o a dual MC system using 1967 Wildcat parts as much as possible. The first obstacle was sourcing the booster and MC. Buick sourced them from two different suppliers, Delco Morraine and Bendix. Due to design dfferences the booster and MC must be used as a pair from the same supplier. It seems that the only available remanufactured boosters available are the Bendix units so I ordered the booster and reman MC from O'Reillys. I had to come up with a new distribution block and lines between it and the dual MC. For those I turned to Inline Tube and chose to get the SS lines to match the other lines on the car. I chose their 1965-1966 Impala dual block and line kit, P/N BLK202LP. This was all of the special order parts needed to complete the swap. While the parts were in transit the next order of business was to remove the OE booster and MC. As I had just replaced them a year ago it was straight forward with no surprises. Once the new pats arrived it was time to swap the single distribution block for the dual block. This is where things got a little tricky. The OE single block has both front brake lines enter from the front. The dual block has the LF line enter from the front and the RF enter from the inside....which is blocked by the power steering return line (green arrow). The dual block has to be moved forward on the frame rail by about 1.5 inches to clear the power steering line. The easiest way I found to do this was to drill and tap another 5/16-18 hole in the frame (blue arrow) about 1.5 inches closer to the front than the OE block mounting hole (red arrow). Doing this requires that you have to trim a little off of the inner fender to clear the LF brake line. Also,the RF bake line must be bent about 90 degrees to align with the port in the block and the LF line shortened by the same amount that the block is moved forward...not easy to do on SS lines. In order to not have to buy a high end flare tool ($$$), I replaced the SS LF line with a custom bent line of regular steel but used the SS fitting and spring. The rear line required a Dorman 3/16F to 1/4M adaptor, P/N 327818.1, to fit the new block and take up some of the difference in length. Rebending the rear brake line to fit was no problem. Now onto the booster...
Mounting the booster wasn't as easy as anticipated. The mounting hole pattern is slightly different. I could only get 2 of the 4 studs in any of the 4 holes at the same time. I had to drill out the mounting holes in the firewall to 1/2 inch to allow clearance for the studs and to allow the booster's rod end to fit over the pin on the brake pedal. To make the latter easier I filed a small chamfer on one edge of the rod end hole to assist in assembly. To ensure that there was adequate clamping surface for the booster mounting I replaced the OE 3/8-16 nuts with 3/8-16 locking flange head nuts. I snugged up the nuts and then pressed the pedal several times to allow the booster to center itself in the larger mounting holes. Note that the OE 1964 booster is 9 inch diameter whereas the 1967 booster is 11 inch diameter. There is just enough room to package the larger booster in the 1964 engine bay. The larger booster also reduces the amount of force required by the driver to stop the car. I then mounted the MC to the booster to test fit the lines going to the new block. I got lucky and the front line just cleared (1/16 inch gap) the windshield washer bottle. Some minor tweaking had all of the lines connected to the block and the MC. I then removed the MC for bench bleeding and reinstalled it. After doing a final connection/tightening/leak check on all line I borrowed the wife's foot to manually bleed the brakes. As you might imagine there was a lot of air trapped in the lines. A quick test drive showed that it took about 25% less force to stop the car than before. Not only did I get a safer system but also better performance...a win/win. Total cost was just over $200, including the core charges for the MC and booster. A small price to pay for pece of mind.
Encountered identical mounting issues, but with a little ingenuity and perseverance went together quite nicely along running all new lines to all 4 new cylinders. An upgrade well worth the time and $ especially for safety sake.
After loosing the brakes one night in my '62 (blew out a wheel cylinder) I swapped to a dual reservoir master. I was lucky enough to find a master/booster setup at O'Reily, with a Delco Moraine booster, and it bolted right up. I re-used the factory distribution block, and plumbed the factory rear line into the new line from the master with an adapter. I plumbed the brake light switch into the now unused port on the distribution block. This is probably one of the smartest upgrades folks with an early single reservoir master can do!
I did the identical swap on our '62 LeSabre. I purchased everything from AutoMasters, a local parts store. And, as Andy stated, I feel it is one of the smartest upgrades. I've done several swaps. Anyone who had a single master cylinder system failure has to agree.
I sourced a 67 booster and MC. The MC I have is 3/16" - 3/16". I plan on utilizing the stock distribution block for the fronts brakes and brake light switch (63 used a hydraulic brake light switch), the rear line I am going to run directly to the rear axle brake hose.
On our '65 Skylark, I used a brake line kit for a '67. When I ordered it, I told them what I was doing.
