Ever since my wife plonked her rear onto her Brooks B67 it has squeaked like a frightened mouse on any stroke pedaled with intent.  I had tried various suggested remedies without success but chance had me stumbling on the one that has worked for her saddle.  B67s and Flyers are popular saddles amongst cycle tourists so I thought I would share what I did to fix the squeak.

Between the springs at the back and the tensioning bolt at the front is a wishbone shaped thingamabob that moves slightly and rubs on the female connector through which tensioning bolt passes.  A dab of grease at the contact point was all that was needed to shut the saddle up.

Jean well diagnosed and cured. 
I recently also had a case of annoying squeaky Brooks saddle. Initially I blamed pedals, cranks and BB but eventually worked out the real source. The B17 saddle! I wasn’t quite as specific in sourcing the cause as you. I dabbed a few drops of light oil on every metal edge I could see under the saddle, and then applied a generous amount of dubbin to the leather. Problem fixed. Squeak gone and the bike is humming along.
Now I just have to fix the squeaking and clicking joints of the ageing rider. 

I was able to fix a years-long squeak on a Brooks saddle by applying a good 'machine oil' to everywhere that metal touches metal and nowhere that metal touches leather, and then jostling the metal 'horn' back and forth a bit. Silent! We'll see how it holds up, but it was easy enough I don't mind doing it every now and then.

Oooh, thank you! I have the same saddle and it is very talkative. 

Alas, the saddle in the photo now rests with the Grand Cycle Tourist of the Universe after both its rails snapped within seconds of each other just outside Junin de los Andes in Argentinean Patagonia at the end of last year.

Hi J-M

How many thousand km did your wife ride on it before it failed? 

About forty five thousand kilometers.  Both rails snapped at the point where they exited the seat clamp so I am guessing some metal fatigue had built up there.  Perhaps too much of the seat was aft of the seat clamp causing excessive flexing.  The rest of the saddle was still perfect.

I think the seat did well. Most,  likely never get that ridden that many kms. I am sure your wife misses it. 

Surely that can be buffed out, good as new?  :)

I agree ... independently found this to be the source of major squeaking and other cranky noises from my Champion Flyer and B67s ... My solution (success) was to slide a 1/4" ID , 1/2" OS, 1/8" thick nylon washer (49 cents at a hardware store) (shown as the white component) between the tension shackle and the tension pin stop ... (same place you highlighted). The tension keeps it in place, but you can also put a piece of sticky tape over the area. No more metal on metal, so it stays quiet.