New brake line for the CB550

Over the summer it was time to pay some attention to the front brakes of the trusty 1977 Honda CB550K. The outer brake line had cracked. There must be an inner hose as well, because no fluid leaked out, but it was still rather nerve wracking to see. Add in a very mushy lever feel, and it was time to replace some parts.

I decided to go with a stainless steel braided line. Stainless steel lines add firmer braking because they don’t expand and contract the way rubber hoses do. With only a single solid brake disc on the front, any added braking power is welcomed. I kept the stock master cylinder, caliper and the pads on the bike still looked good. I replaced everything in between the master and the caliper.

The stock setup consists of, starting at the master cylinder, a length of line that goes behind the headlight bucket, into a block. This block is where the wiring for the brake lights ends. Then from this block, another length of line runs down the fork leg to a solid piece of tubing. The solid piece of tubing makes a bend and then goes into the caliper.

In this photo you can see the wiring block and the solid tubing that runs into the caliper, both outlined by yellow boxes.

I didn’t care for this setup at all as there are two extra places for leaks to appear. I decided to do away with this setup entirely, and replace it with one solid length of line.

I got all parts at Dennis Kirk. I shopped there because not only did I previously work there, but they had everything I needed, fast & free shipping, and helpful staff - especially Tim in tech support. He’s the one who helped me put this list together.

• Part #198392 - 32″ Goodridge Platinum Universal Brake Lines w/Chrome-Plated Ends
• Part #191350 - Russell Brake Line Fitting-3/8 in.-24 Inverted Flare-#3 Straight
• Part #191339 - Russell Brake Line Fitting Chrome 3/8 in. /10mm Banjo x #3 Male 90°
• Part #210369 - K & S Hydraulic Brake Light Switch
• Part #27487 - Russell 10mm Aluminum Banjo Bolt Washers
• Part #303574 - Castrol GT LMA Brake Fluid

The brake light switch replaces the normal bolt that goes through the banjo into the master cylinder. This switch bolt has a length of wiring that I ran down with the new brake line, then plugged it into the wiring under/behind the headlight bucket for the brake light. The brake line then runs the entire route down the fork leg, and the small Russell brake line fitting connects the line to the caliper.

NOTE: Make sure you take a measurement of your current brake line. I have a set of drag bars installed, lowering bar height a couple inches. If you have stock or higher bars, you might need a longer brake line than the 32″ one I purchased.

After installing all parts, bleeding the line and testing it out, braking power and feel is much improved. It’s still not modern day bike with dual front wave rotors, but it’s a vast improvement over what was there. I’ll add some photos of the new setup soon. Hopefully this weekend the weather will be nice and I can get some good shots outside.

Hope this helps,
Jeff