Topic: Front brake drag

[tkarahalios]

Hey guys,
I just rebuilt my caliper on my 1975 CB550K1. New stainless lines and also rebuilt the master cylinder.
New seal, used brake cylinder oil and Dow Corning silicone as recommended, honed the caliper body, and used a brass Dremel brush to clean out the seal channel. Now that it's back together I'm worried that it's still dragging too much.

When I lift the front tire off the ground and give it a spin, it seems to go around about 1.5 to 2 times before stopping. Is that okay?
Also I tried to adjust the caliper position bolt to get the 0.006 thousands of an inch gap on the fixed side of the caliper, but the piston seems to not be retracting enough. How big should the gap be between the rotor and the piston side pad?

[bjbuchanan]

Push the piston side in to give yourself some adjustment room. Did you check to see if your caliper arm swings freely? The caliper arm is the part that holds the caliper and bolts to the fork and can freeze up over time. My arm was totally frozen, I had to burn it apart and clean up with new grease and o-rings.

[calj737]

This can also be symptomatic of a air still in the lines from the master cylinder down. The MC has two small return holes in the bottom. Both must be perfectly clear to allow the pressure in the line to abate and the piston to then retract fully.

How is the lever pressure? Was it rebuilt too, or just the caliper? This is often overlooked and the single reason for poor performance of the front brake.

[billingstitan]

+1 on all these suggestions - Also, I ran into this on a 77 CB550 and it ended up being the paint around the edge of the new brake pad. Tore my hair out trying to figure out why it was dragging then someone suggested using a brass wheel to remove that paint and voila, problem solved.