When I put my 2CV6 into storage last fall, I knew I had a couple of niggling problems to deal with. Not surprisingly, the problems were still there this spring when I took the car back out. Nothing major, you understand, just vague steering and iffy brakes! Why worry about little thing like that? In this article, I will talk about the brakes.
The brake problem was a lingering hangover from when I replaced the master cylinder in 2010. Since that time, I had not been able to get the right feel in the brake pedal. The car stopped just fine, but the pedal was inconsistent. The first push would always be a little “long”. A second push brought the pedal right up, but would only stay that way for a few seconds between uses.
I had chosen to install the master cylinder without bench bleeding. Bench bleeding is a technique that fills the body of the new master cylinder with fluid before installing it in the car. In the case of a 2CV, installing the master cylinder has to be done from inside the car, already fitted to the full pedal assembly. If the master cylinder is already full of fluid, that job can be really messy.
So, for a season and a half, I had been assuming that the pedal problem was due to air trapped somewhere in the brake system. I got really good at bleeding the wheel cylinders, which I did at least three times each year, allowing time in between for furtive bubbles to make their mysterious ways along the brake lines to the wheel cylinders. Each time, I was sure that I got the last bubble, and all would be well. Alas, it was never true, and I just became very adept at pumping the brake pedal twice when I used them.
This spring, I consulted the community of experts on the Yahoo Groups site for 2CV topics (2CV-L). Many suggestions were made, including a technique for reverse bleeding (pushing brake fluid into the system from the wheel cylinders). However, the most common recommendation was to adjust the brake shoe eccentrics. These adjusters move the brake shoes closer to the drum to compensate for wear. As a result, the master cylinder does not have to move so much fluid to cause the brakes to come on.
My car has four drum brakes, so both ends have eccentrics and there are two per wheel, for a total of eight. Since I had adjusted the front brakes only 8,000 km earlier, I figured that the rears were the most likely suspects. Unfortunately, 2CV adjusters are infamous for seizing over time, and the rears can be awkward to access from underneath. So, with the help of Terry H I removed my rear fenders, for the first time since I bought the car 12 years ago. To my great pleasure, all the fastenings came off, and soon the car was sitting with naked haunches.
The next step was to apply liberal amounts of penetrating oil and patience. Both of these are indispensable tools for a home-based mechanic. Each time I applied the penetrating oil, I also firmly but gently pulled and pushed with a wrench on each adjuster. This gentle stress has the effect of creating micro-cracks in any accumulated rust and corrosion, allowing the penetrating oil to seep deeper and deeper into the joints to do its magic work.
After several rounds of “soak and wait”, I got serious and started trying to actually move the adjusters. Having heard that these beast can be very fragile, and knowing that the consequences of breaking one would be to have to dismantle the rear drums, I took my time, and rotated my efforts around each of the four adjusters. Each time, I would increase the torque I was applying, always worried that I would hear the “snap!” that tells you that you have broken off the bolt.
To my complete joy, with a sharp crack one of the adjusters finally moved. I squirted in yet more penetrating oil, and began to work the wrench forward and backward. Each cycle freed up the adjuster more and more. I continued around the four adjusters until all of them were free. Hooray!
Now Terry and I began the adjusting process, one of us spinning the tire as the other progressively moved the brake shoe outwards towards the drum, until contact was made. Then you have to back the adjuster off to free the wheel, and finish by again adjusting outward until just before the shoe would contact the drum. It is very important always to finish with an outward adjustment, not a backing off.
Surprisingly, three of the adjuster required barely 1/16 of a turn, and the fourth barely 1/8 of a turn. Nonetheless, I hopped into the driver’s seat and confidently pushed the brake pedal. No improvement! Dang!
Dejectedly, we replaced the rear fenders and lowered the car to the ground. We were out of ideas.
Later in the week, as I was driving the car, it occurred to me that the parking brake had been becoming less and less effective over time. In thinking about that, I started to put two and two together. The parking brake on a 2CV works on the front brakes, by pulling the brake shoes into contact with the drums by means of a cable. Since I was now running out of travel on the parking brake handle before the shoes started to touch the drums, maybe in fact the shoes were out of adjustment, despite having been set only 8,000 km ago. What the hell, it was the last possibility I could think of, no matter how remote the chances.
I returned to the garage and grabbed the only wrench that will fit on the front adjusters: a 14 mm open ended wrench, not the ideal weapon to avoid rounding the bolts. With the help of my son Scott, but without much hope, I started the process of adjustment, using the open-ended wrench and a piece of square tubing for leverage. Happily, these adjusters moved quite easily. Much to my surprise, the adjustment required was much greater than for the rears. Each of the four needed nearly 1/4 turn of adjustment.
With great trepidation, I slid into the driver’s seat, and pushed the pedal. It was firm, short, and consistent. Hallelujah!
With that, a two-year story came to an end. The moral is never overlook the simple adjustments, and don’t make assumptions. These are wonderfully simple cars, and the answers to problems usually are just as simple.