Loosening Mafac brakes

[Apple Tree]

No, not a bodge; the same levers can be used with either brake system. The process is pretty much the same.

1) Best to remove the wheel.
2) Identify which cantilever arm has the removable straddle cable end.
3) With a wide hand pinch the arms together and remove the straddle cable from its arm and also from its pull hook.
4) Tension is now released from the brake system and you carry on as previous.

Important that you use a box or tube spanner of the right size for the brake lever nut. Don't round the corners of it. Mafac produced a little cyclist's tool kit in a plastic pouch that included such a spanner but a socket of the right size should just go in ok.
If there is just not enough flexibility in the brake cable to allow you to get a spanner on the brake lever nut you may just have to bite the bullet, undo the nut holding the cable to the pull hook and pull the brake cable through the lever and completely out. If there is a metal cable end fitted you will just have to cut it off. With the cable totally removed this will give you plenty of room to get the right size spanner on the nut and make your adjustments. Then reinsert the cable tighten up the pull hook nut and finish off including squeezing on a new cable end.
It may sound a lot of work but really a couple of minutes will do it.

 

[Ajoten]

No straddle cable on my side-pull brakes (non Mafac, it's only the levers that are). But having removed cable from the caliper and got enough slack I found my socket wrench - which appeared to fit - was in danger of rounding out the nuts. Might need a squirt of something. Or professional intervention.

 

[Apple Tree]

Sorry, I assumed the brakes were a version of Mafac as well as the levers. Mafac did not make a caliper brake. The levers should still work well with most brakes.
Sounds as though you need a better fitting socket. The housing of the lever may be stopping the socket making good contact with the nut. You really need a thin socket that will go all the way in. If you round the nut you really will have a problem. Best go a bike shop that should have a good range of tools.

 

[Ajoten]

I fear so

Thank you for everyone's contribution though. I guess this whole vintage project malarkey is about learning stuff as much as actually doing stuff...!

 

[Apple Tree]

Absolutely ! You can never know everything which is why restoring classic bikes is endlessly fascinating and subject to a lot of trial and error.

You have taken your first steps. Well done !