Vintage Brake Service
The single-piston calipers on my Seca only worked adequately when they were new, so the ravages of time in a shed in Michigan reduced them to little more than unsprung weight. fixed them up good as new—better even, if you count the solid feel from the new steel-braided brake lines.

One of the least glamorous tasks involved in getting an old bike back on the road is rebuilding its brakes. Even when a 1970s to 1990s Japanese bike is otherwise properly stored, changing the brake fluid is often overlooked. In addition to being mildly corrosive and potentially harmful to paint and finished surfaces, DOT 3 and 4 hydraulic brake fluid is hygroscopic, meaning that it absorbs water from the air. When a bike sits, particularly outdoors, water absorbed by the fluid acidifies and eventually begins to corrode the metal parts in the brake system and attack the rubber seals. At the same time oxygenation is slowly causing the rubber hoses to harden. When the time comes to resurrect the machine, if the master cylinder can even pressurize the system, quite often the brake calipers will seize and lock the wheel.

That was the case when I took delivery of my 1982 Yamaha Seca XJ650RJ from the seller in Michigan. We had to lift the front wheel onto a moving dolly in order to roll the bike into the shop, where I was able to carefully pry the front caliper pistons back into their bores with a screwdriver. Further inspection made it clear that a front brake rebuild was required—there was dark, goopy fluid in the system and corrosion in the master cylinder, reservoir and around both front caliper pistons. Fortunately none of this was a surprise—I knew the bike had been sitting in a shed in Michigan for quite some time. I understand it gets cold and wet there….

Anyway, my limitation when it comes to this kind of job isn’t aptitude; it’s time and equipment. I can remove the components from the bike easily enough, but don’t have the tools or know-how to hone master cylinder or caliper bores, or the time to cross-reference part numbers and hunt down the right aftermarket and OEM replacement parts.

That’s where Matthew Wiley comes in. He runs, which specializes in component service and repair for 1970s–1990s motorcycles. Wiley has been an American Motorcycle Institute certified mechanic for 35 years and was working with these motorcycles when they were new, so he knows his way around their components. As long as you’re competent enough to remove your bike’s brakes, fork, shocks or carburetors, Wiley will do the rest. They will be returned cleaned, serviced, rebuilt, setup and ready to install. uses high quality, made-in-Japan rebuild products from K&L Supply Company, along with New Old Stock (NOS) OEM parts as needed.
The refreshed calipers mounted on the author’s 1982 Yamaha Seca.

After Matt received my Seca’s brake components, he called me with a quote to do the work, which I thought was pretty fair. Disassembling the leaky master cylinder revealed typical grunge build-up along with hardened, leaky rubber components. After a careful cleaning the bore was honed and a new K&L Supply rebuild kit installed along with a new reservoir diaphragm and hardware. Then the paint was freshened, resulting in a new-looking master cylinder.

When Matt disassembled the calipers he found that the sliding pivots were rusty and sticking, the caliper seals had hardened and there was white powdery corrosion in all the seal grooves. Both of the caliper pistons also had corrosion and pitting in the hard chrome. K&L Supply seal kits were used, but after carefully prepping the caliper bores Matt had to install OEM NOS pistons since K&L did not have them for my bike. All of the slider floating pins were cleaned, polished and greased to insure the calipers floated properly on the carrier brackets. Since I had installed new pads when I received the bike, Matt reinstalled rather than replace them—job done.

Thirty-five year-old rubber brake lines can lead to spongy brakes, so I also had Matt build a set of braided steel lines to replace the originals. Sending the original lines along with the brakes made it easier for him to match the lengths, fittings and banjo clocking, so when I got them back they installed quickly and easily. New sealing washers were included, and an installation tips worksheet to aid installation, since priming and bleeding a dry brake system can be a challenge. My first test ride after everything was reinstalled was pretty satisfying—I hadn’t been able to ride the bike since buying it. The front brakes worked marvelously, with good feel at the lever, no sponginess and good power.

Pricing varies by application and component styles, but the typical price range for brake rebuilds is $100-200 per caliper or master cylinder. Steel-braided brake lines run $40-75 per line based on length and fittings, with package prices available. All jobs are quoted upon inspection, and turnaround time is typically 7-14 days. Wiley knows exactly what to look for and is highly detail oriented—critical factors when it comes to vintage brakes.

In addition to brake caliper and master cylinder rebuilds and made-to-order braided-steel brake lines, does carburetor and fuel petcock rebuilds and fork and shock rebuilds and upgrades.


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