Author Topic: Honing master cylinder  (Read 314 times)

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Offline Astute Greaser

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Honing master cylinder
« on: May 23, 2022, 01:19:07 PM »
My 14mm ASCO front master cylinder is apart at moment. There is a mark just past the small compensating port where the return spring lives.
Looks like the position of the front cup seal when brake fully actuated.
102649-0
It may polish out with cloth, autosol, pushed with wooden stick. However if not and I have to hone, has anyone had success with one of these.
Note I can't use the 3 leg hones as they do not go down to 14mm.
https://www.amazon.co.uk/Research-Chamfer-Flex-Hone-Silicon-Diameter/dp/B00DB88RJ4/ref=sr_1_1?crid=3P4VPNFMQD2ML&keywords=flex+hones+14mm&qid=1653306351&s=industrial&sprefix=flex+hones+14mm%2Cindustrial%2C52&sr=1-1
Cheers
-Mike

Offline Astute Greaser

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Re: Honing master cylinder
« Reply #1 on: June 06, 2022, 02:38:42 PM »
I got the tool and worried myself that it would be too aggressive for aluminum  ???. Decided it was really intended for cast iron and stainless. Clever idea though.
102711-0
I had managed to improve the mark. Got the vernier out and measured where the mark was in relation to the front cup seal. Close but just missed. So didn't take the chance. Dug out the original piston set and found mark had come from the spring, from when it was all dried up with crystallized dot3 and jammed in full on position.
Brake cleaner, dot4 and reassembled. Putting the circlip back works easier when you put the ends inline with the scallop cut out for the lever. More room for the circlip pliers.
The boot cover was a real pig  >:( >:(. Dia 4mm hole over 10mm piston end, really  ???. Turning boot back on itself, red grease and couple of tea spoon ends did it after half hour. The factory must have a special tool for this  ::)
Bled and working  :) :)
« Last Edit: June 06, 2022, 02:40:39 PM by Astute Greaser »