QuestionAfter replacing the front brake line and bleeding the system on my cb350g I have found that my caliper is compressed so far that my front wheel won't spin. I am still in the process of restoring this bike, and have yet to ride it, but want to make sure that everything is square up front before I do. Will the caliper loosen up once it starts moving or do I have to perform a further adjustment to make sure everything is copasetic?
Thanks,
~Eli
AnswerEli, there are two things that can causes caliper seizures, like that.
1. Caliper piston seal ring has swollen up from corrosion in the caliper body groove.
2. There is a small bleed port in the master cylinder that has become blocked. It is the closest to the brake line fitting and is very tiny.
If the bike has been sitting for a long time, both the master cylinder and caliper need cleaning rebuilding thoroughly. Parts are available from Honda or sometimes after market sources like K&L dealers. A new brake line would be a nice idea, as well.
If the master cylinder still has clean fluid in it, use the hydraulic pressure to push the piston out of the caliper body, after you have removed the caliper from the rotor and fork leg bracket. You may have to whack the caliper body a few times with a soft-faced mallet to get the piston to back off enough to get the caliper off the rotor.
Clean the caliper body groove carefully, after you have removed the piston and the sealing ring. Lube with fresh brake fluid, open the bleed screw and push the piston back into the body over the edges of the sealing ring.
See below for more references and ideas.... including
http://oldmanhonda.com/MC/Rbrakes.html
http://en.allexperts.com/q/Motorcycle-Repair-837/1973-honda-cb350G-disc.htm
http://en.allexperts.com/q/Motorcycle-Repair-837/Rear-Brake-pedal-Caliper.htm
http://www.hondabikes.net/forum/archive/1975-cb500t-brake-caliper-seized-5169.ht...
FYI the brake assy is very similar to the later CB350F-CB400F, CB500-550F, etc..
Bill Silver
