O Ring Brake Caliper Conversion

[John L.]

I am in the process of converting the front calipers on my “66 to O ring seals. I have the O ring kit and taken one of the calipers apart, cleaned and lubricated it and ready to rebuild. When I insert the spring and piston into the bore it’s a very tight fit with no “free play” movement in the bore, should I be concerned about this once I reinstall the rebuilt caliper? This is a learning experience since it’s my first time doing this, thanks

[Owen L.]

Sounds pretty tight. Try fitting the piston without the spring. The service manual states these clearances:
Screenshot 2025-08-13 at 9.24.46 AM.png