by Art Gardner

If you replace brake lines and/or replace or re-do wheel cylinders, it can be a chore to get all of the air back out of the lines and cylinders. Here is a trick I came up with recently (this probably been used by lots of mechanics over the years, but it only occurred to me in the last month or so).
The idea is to fill the lines and the cylinders as full as possible with fluid before installing them. Recently, we replaced the rear lines, rear hose, F-to-R line, and rebuilt the rear wheel cylinders on my ‘50. To avoid endless pumping and bleeding of the brakes, I filled the cylinders as full as I could with fresh fluid, then attached the new (relatively short) steel lines and snugged them up. Then I filled the line and the cylinder the rest of the way by pouring brake fluid down the line, using a skinny awl to lead the fluid into the line like a reverse funnel. (See drawing on next page.) After filling the line and cylinders completely, we put a tight rubber cap on the end of the line and installed the cylinder/line. For the flexible rubber brake hose and the F-to-R steel line, we did basically the same thing.
We had removed the wheel cylinders to rebuild them and were installing new lines at the same time. So pouring the fluid into the lines up was no trouble. If you were doing it with the wheel cylinders still on the car, you could put a rubber hose on the end of the line and bend up the rubber hose to give you a vertical run to pour into and to provide the elevation change needed to force the air to rise up and out of the line. If you do it with the wheel cylinder still on the car, you might need to open the bleeder valve to let some of the air out that way. Since I had the lines oriented vertically with the wheel cylinders off the car, I didn’t need to open the bleeder and the air escaped up the line.
As a result, there was very little spillage and it didn’t take very long to fill the system or bleed the brakes. The net effect is that when we bled the brakes, there was very, very little air in the system that needed to be purged. We had a firm pedal almost from the start and the entire bleeding process only took about 10 minutes.

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by Art Gardner

Many of you are aware of the tendency these days to “update” the car’s brakes with disk brakes in an effort to make the car safer. In my opinion, the biggest danger with the original 1949 Cadillac brakes is the lack of a second circuit, not raw stopping power. Up through 1961, I think, the brakes were all single circuit. Certainly in 1949 they were single circuit. That means that if you pop a line or hose or wheel cylinder anywhere on the car, you will lose ALL brakes all at once. Dual circuit brakes, which I think started with the 1962 Cads, eliminate that risk and leave you with either front or rear brakes in the event of a calamity. Many people will say, but “hey, I have never had a problem, so why change anything.” But when you do have a problem, this is a BIG problem.

So, the most important thing, in my opinion is to make sure the original parts are PERFECT, especially the metal lines. Brake fluid is hydrophilic, meaning it attracts moisture (right out of the air). The water that gets in the lines in this way rusts the metal lines from the inside out. They can look perfectly normal in a visual inspection, but be rusting away on the inside. One day a pinhole pops though and you lose all brake pressure. This happens more regularly than you might think, which is why the government eventually outlawed single circuit brakes. This fluid-borne rust is also how your wheel cylinders and master cylinder get pitted. The fix is to replace the plain metal lines with stainless steel lines. Put on all new hoses. Sleeve the wheel cylinders and the master cylinder with brass or stainless steel. Flush out the brake fluid and replace it with new fluid every 2-3 years. Do that and the original drum brakes should be safe for a long time!

If you want to make them even safer, you can put in a dual circuit master cylinder. It takes some extra work and plumbing, but to me it is worth it for the additional peace of mind. This is what I did with my last ‘49 6107 Club Coupe and am doing it to my new ‘49 coupe. I developed a nice kit for installing such in the original mounting place on the frame, so everything looks great and works correctly. I haven’t worked out how to do this on my 1956 Series 60 Fleetwood, but I am still noodling on it (as there is precious little room at the front of the 56 power brake booster for a dual circuit master).

I tried a disk brake “kit” on my last 49 and it was a disaster. I never did get it to work right, so I gave up and went back to the reliable drum brakes (augmented by my dual circuit master kit using a modern Wilwood dual circuit master).

I drive my old Cadillac’s as daily transportation. Right now, I use the ’49 fastback in the cold months (it is black and has no air conditioning) and use the ’56 60S in the warm months (its factory air works great). So I am relying on my good old drum brakes every day to stop my cars and keep me safe.

If you use the car only occasionally, such as for club events a few times per year, you might feel less motivated to be so finicky about brakes and might be tempted to do the minimum, instead of the maximum, in restoring the brakes. I can understand that tendency. But keep in mind that, as the song says, rust never sleeps and the corrosion inside the lines and the cylinders continues whether you use the car or not. So you can still have a safety issue with the brakes, even if you only use the car a few times per year.

If you keep the single master, but make the entire system perfect, you should be okay. A dual circuit master is a nice peace of mind as an extra safety measure, but you should be okay without it if everything else is right.

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