Alfa Romeo brake system overhaul, Part 7

I’ve always likened working on an old car, when there’s little or nothing in the way of published instruction, to dancing the tango. It’s two steps forward, and one step back. Two forward, one back. And repeat….

In the last post about the Alfa’s brakes, two weeks ago, I wrote about the awkward position of the brake master cylinder. Like so many cars with pedals coming up from the floor (what Alfisti call “standing pedals”), the master is underneath, bolted to the pedal box. When I removed the master cylinder last fall, there were no written instructions to follow. I loosened the pedal box just enough to lower it and access the two bolts holding the master in place. The removal was such a chore that frankly I had been dreading the reinstallation.

Re-reading my words in that last post, I see that I was unintentionally vague. The sentence that now bothers me reads “Once the lines to the master cylinder are done, I need to reinstall the pedal box in the driver’s footwell, as all three pedals had to be loosened/removed to gain access to the master.” My sentence leaves it completely unclear whether I had removed the entire pedal box, or had merely loosened it, when in fact it was the latter.

Why am I harping on this? Because I found myself doing the tango. In the process of attempting to reinstall the new master, I ended up completely removing the pedal box from the car. If only I had done this during the initial disassembly! The hang-up was a bracket which I had mistakenly identified as part of the transmission cross member, but is a bracket for the front exhaust pipe. Laying on my back, on the garage floor, holding a flashlight, and trying to focus through my progressive lenses made its correct identification difficult. Once I realized that it could be safely removed, I undid 5 bolts and it was off. Suddenly, the entire pedal box was in my hands. Eureka!

Pedal box on my workbench. New master is in front.

Since the exhaust bracket was off, I replaced the two rubber bushings inside it, cleaned it up, and repainted it with Eastwood Chassis Black. When friends ask why this brake job isn’t finished yet, it’s these “might as well as” side jobs which eat up time, but are important to complete.

 

With paint open, I dipped the bolt heads and nuts in it. Drilled wood holds them while they dry.

With the new master cylinder bolted in place, I reinstalled the pedal box, sealing it against the unibody with fresh dum-dum (I have a box of 3M dum-dum that’s probably 25 years old, and that stuff stays pliable!). The two final brake lines were bent to line up with the threaded inserts on the master, and I was happily surprised that I got the threads to “bite” after just a few minutes of trying.

Brake lines at master, ready to be bent to shape

The time had come to add fresh brake fluid to the system. I filled the reservoir, attached the little magnetic one-man bleeder bottle from Eastwood to the right rear caliper bleed screw (always start with the brake furthest from the master), and began to pump the brake pedal by hand. Forum posts on the Alfa Bulletin Board (AlfaBB) recited tales of horror about the difficulties in bleeding Alfa hydraulic brakes. I believe that later cars with dual circuits AND dual servos can be a challenge to bleed. I was happily shocked that I had fresh fluid coming through the hose on the bleeder screw on the second or third try.

This item, under $10, makes one-person bleeding a breeze

I was less happily shocked to also see that I had some leaks. There were two leaks at flare fittings that still weren’t tight enough. An eighth of a turn with the 7/16” flare nut wrench solved that. I continued to add fluid and pump the pedal, moving from right rear to left rear to right front to left front. But then a larger fluid leak sprung, from a lousy location: the master cylinder. I got under the car, but both lines at the master were as tight as I dared to make them. My heart sank. Could the new master cylinder be defective?

When you’re doing the tango, and your feet start to go in a direction that could make you trip and fall, it’s sometimes best to get off the dance floor. I put down all the tools, exited the garage, went for a walk, and came back to have lunch. (I learned during the Isetta restoration that before anxiety drives you to act hastily and BREAK something, walk away, think about it, then go back to it.)

An hour later, I believed I had diagnosed the problem, without even touching the car. The leaking line ran from the exit port on the master up to the brass four-way junction block on the firewall. I remembered that when I had formed that line, I told myself that it was “symmetrical”, that is, the same flares and the same flare nuts on each end. While the flare NUTS were the same, the flare at the master needed to be an ISO bubble flare, and I had formed a 45 degree double flare. It took about two minutes to pop that line out of the master to confirm my diagnosis. Yup – I formed the wrong flare fitting.

Oops. Old line at left is bubble flare; new line with double flare doesn’t match.

Back to the two steps forward and one back routine. It was a complete pain to remove that line, cut off the wrong flare, make a new flare, and fit the line back in place. However, the rapid diagnosis made up for it. The fixed line was back on the car, bleeding resumed, and there were no leaks. In a short while, I had a pedal! I’ll bleed the entire system one more time, then the hydraulic work will be done.

 

This is better.

 

All photographs copyright © 2020 Richard A. Reina. Photos may not be copied or reproduced without express written permission.

2 thoughts on “Alfa Romeo brake system overhaul, Part 7

  1. Well done keeping mental track of those various flares. That’s the sort of thing that can drive one crazy looking for a problem that’s not there. Great Tango metaphor. Never knew you are such an accomplished dancer.

    Like

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