03-28-2020, 01:41 AM
Sure, here is what i found when i searched "motorcycle master brake cylinder hole" in google and opened the results a new tab;
1; a drawn picture someone talented drew showing the inner workings of a master cylinder;
http://www.howmotorcycleswork.com/articl...cle016.htm
2; The series of explanations that leads to the picture under "howmotorcycleswork" site;
http://www.howmotorcycleswork.com/sitemap.htm
3; another clearer cutaway diagram of the parts;
https://www.accessnorton.com/NortonComma...ing.22837/
4; an article about the hole and you can see the hole clearly when you click on the picture twice to magnify it for a closeup;
https://www.reddit.com/r/motorcycles/com...turn_port/
5; a good article pretty close to what we have in our bikes;
https://motofaction.org/motorcycles/hond...d-part-01/
The first time i looked at mine i thought the hole was drilled by mistake and left there, only after seeing what it was supposed to look like did i find the obstruction and when i cleared it out all the air escaped when i worked the handle slowly and the pressure buildt up correctly wnen all the air bubbles worked themselves slowly to the top of the cylinder, even a small amount of air in the line can compress and stop the brakes from building enough pressure to engage normally.
This system is very simple and reliable and requires minimum maintenance but because the brake fluid is hygroscopic ( it absorbs moisture from the air ) it needs to be replaced regularly otherwise the moisture builds up inside the system and corrodes the parts inside.
For the same reason i push the caliper pistons all the way back into the calipers after cleaning them on the outside and empty the lines to expel as much old fluid as possible when i replace it with fresh fluid.
How quickly does it absorb moisture? in my sample ( a soda bottle cap ) it took 15 minutes to activate the first led and was unusable ( red led ) after 1,5 hours at 4%, much quicker than i had thought, if you pause at 14 sec. you can read the results of two tests;
https://www.youtube.com/watch?v=HPCvEoPlNlU
Here i use a small trick to replace the seal on the piston and show what's involved if you're interested;
https://www.youtube.com/watch?v=9tC9qYyv-OM
Just select which part you're interested in.
1; a drawn picture someone talented drew showing the inner workings of a master cylinder;
http://www.howmotorcycleswork.com/articl...cle016.htm
2; The series of explanations that leads to the picture under "howmotorcycleswork" site;
http://www.howmotorcycleswork.com/sitemap.htm
3; another clearer cutaway diagram of the parts;
https://www.accessnorton.com/NortonComma...ing.22837/
4; an article about the hole and you can see the hole clearly when you click on the picture twice to magnify it for a closeup;
https://www.reddit.com/r/motorcycles/com...turn_port/
5; a good article pretty close to what we have in our bikes;
https://motofaction.org/motorcycles/hond...d-part-01/
The first time i looked at mine i thought the hole was drilled by mistake and left there, only after seeing what it was supposed to look like did i find the obstruction and when i cleared it out all the air escaped when i worked the handle slowly and the pressure buildt up correctly wnen all the air bubbles worked themselves slowly to the top of the cylinder, even a small amount of air in the line can compress and stop the brakes from building enough pressure to engage normally.
This system is very simple and reliable and requires minimum maintenance but because the brake fluid is hygroscopic ( it absorbs moisture from the air ) it needs to be replaced regularly otherwise the moisture builds up inside the system and corrodes the parts inside.
For the same reason i push the caliper pistons all the way back into the calipers after cleaning them on the outside and empty the lines to expel as much old fluid as possible when i replace it with fresh fluid.
How quickly does it absorb moisture? in my sample ( a soda bottle cap ) it took 15 minutes to activate the first led and was unusable ( red led ) after 1,5 hours at 4%, much quicker than i had thought, if you pause at 14 sec. you can read the results of two tests;
https://www.youtube.com/watch?v=HPCvEoPlNlU
Here i use a small trick to replace the seal on the piston and show what's involved if you're interested;
https://www.youtube.com/watch?v=9tC9qYyv-OM
Just select which part you're interested in.