The previous post covered the installation of the new disk brake rotors and calipers. The next step is to hook everything up.
As previously mentioned, I’m upgrading from the original single master cylinder to a dual master cylinder. This both provides additional safety in case a brake line or wheel cylinder fails and also provides a proper balance between front and rear brakes.
Since the power brake booster is almost sixty years old, I sent it out to Power Brake Booster Exchange for a rebuild and installation of a new master cylinder. They confirmed that I’m going with front disk/drum rear brakes and provided the correct master cylinder. I also had them return the original master cylinder – I’m saving all of the original parts in case someone wants to return to a factory configuration in the future.
Once the booster and master cylinder were installed it was time to run new brake lines. I’ve had brakes fail on older cars due to pin-hole leaks from rusty brake lines. Fortunately the failure was gradual, but it left me stranded overnight on the side of the road on a long trip. This has lead me to a philosophy of completely replacing all parts when doing brakes on old cars.
In the past I’ve used regular steel brake lines. They work well, but they are difficult to bend and prone to rust. I’ve read about new cupro-nickel brake lines – an alloy of copper and nickel, which is used on many new cars. Cupro-nickel is completely corrosion free, so it will never rust out. It is also supposed to be easy to work with. Unlike steel brakelines which come in straight segments which are typically 5’ or 6’ long, cupro-nickel comes in 25’ rolls. This allows you to run a single continuous brake line with no fittings – another way to minimize leaks!
The cupro-nickel line is indeed easy to work with. I tried a couple of different techniques for bending it, and ended up doing most of the work with a set of bending pliers which have radiused jaws:
These pliers make it easy to make bends wherever you need them without crimping the brake lines.
Armed with these tools I first routed the line for the right wheel. This required forming a large arc to match the front cradle of the engine, and then routing the line past the A-frame mounts, over the frame rail, and up to the bracket for the flex hose. This job went surprisingly well.
Using steel lines this would have required two or three pieces – and I probably would have had to re-do it two or three times! The cupro-nickel is easy to tweak and adjust. I’m pretty well sold on these new brake lines.
The front brakes require a T-fitting to split the line from the master cylinder into lines to the left and right wheels. So, decide on a good place to mount the T-fitting, adjust the brake lines to it, and install everything. Of course, you have to remember to install the nuts on each segment of line before you flare the ends…
Speaking of flaring, brake lines require a double flare – which I hadn’t done before. So I purchased a fairly highly rated flaring kit, cut some short lengths of brake line, and started making practice flares. I wasn’t happy with the results – the flares were frequently off-center and poorly shaped.
There is another style of double flaring tool that is supposed to be easier to use – almost idiot proof, in fact. This style is more expensive and requires separate tool for each size of line. Since stopping is important and the tool was less than $50, I decided to give it a try.
It turns out that the reviews were right – the tool is easy to use and produces good flares. It is self centering and self adjusting: just follow the directions and it “just works”. The ability to flare a line on the car is surprisingly useful – run and fit the line, cut it to length, flare it in place, and tighten the fittings.
Speaking of fittings, I mentioned that it is necessary to install the nut before flaring. I remembered to do this, and was rather proud of myself. When running the lines to the master cylinder I just stuck the end of the line in the master cylinder port to get everything dry fitted. I then installed the nut, flared the end – and discovered that the nut was the wrong size! This was the same size nut that worked everywhere else, but not on the master cylinder.
Fine. Dig around the collection of brake line nuts and find one that fit. Cut the flare off of the line, remove the old nut, insert the new nut, and flare it again. Fortunately there was enough line to still reach the master cylinder, so this wasn’t a real problem.
Now being paranoid, I found another nut the same size and tried it in the other port on the master cylinder – and it didn’t fit! So, dig around in the fittings, and find another one that fits. NOW install the nut on the line, flare it, and screw it into the master cylinder.
After thinking about this for a few minutes, it almost makes sense. Using different size fittings on the ports prevents people from switching the front and rear brakes, which would result in seriously unbalanced braking. Something else to watch out for on future brake jobs…
In any case, everything is now hooked up to the master cylinder:
The last bit is the rear brake line, running along the frame rail. The silver wrap on the line is a stainless steel spring that protects the brake line from rocks and other hazards. It is used everywhere the lines are exposed to flying rocks and similar threats.
At this point the brakes are almost done. I need to add brake fluid and bleed the air out of the lines. I also need to rebuild the rear brakes. The rear brakes are a challenge due to the special tools needed to remove the rear drums. I may just pull out the whole rear end and have it rebuilt.
Next: The WorcShop