Author Topic: Brake master cylinder rebuild kit  (Read 1614 times)

Offline Nurse Julie

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Re: Brake master cylinder rebuild kit
« Reply #15 on: August 11, 2020, 05:32:13 PM »
Gently push a very, very fine piece of wire down the return hole. Don't make the hole any bigger than it is, as the system won't work properly.
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Offline ewanhughes

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Re: Brake master cylinder rebuild kit
« Reply #16 on: August 11, 2020, 06:33:30 PM »
Gently push a very, very fine piece of wire down the return hole. Don't make the hole any bigger than it is, as the system won't work properly.
Are we talking a guitar E string thickness or something finer Julie?

Offline Bryanj

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Re: Brake master cylinder rebuild kit
« Reply #17 on: August 11, 2020, 07:44:43 PM »
Whats a guitar?

Offline Nurse Julie

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Re: Brake master cylinder rebuild kit
« Reply #18 on: August 11, 2020, 08:57:42 PM »
Gently push a very, very fine piece of wire down the return hole. Don't make the hole any bigger than it is, as the system won't work properly.
Are we talking a guitar E string thickness or something finer Julie?
E will be just perfect 🤣🤣🤣
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #19 on: August 11, 2020, 10:57:14 PM »
Are we talking a guitar E string thickness or something finer Julie?
E will be just perfect 🤣🤣🤣

Light, medium, or heavy gauge?   ;D

Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #20 on: August 12, 2020, 11:56:51 AM »
Oh dear, my poor master cylinder thread...

Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #21 on: August 23, 2020, 06:54:57 PM »
I'm reassembling my brake system - I'm having a difficult time getting the brake switch junction back in place.  It's really fighting me.  This is the only way it seems to fit, slightly crooked and the tab on the right (of the photo) in contact with the fork clamp (see arrow).  Is this right?

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Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #22 on: August 23, 2020, 07:54:59 PM »
Never mind... I don't know what happened, but when I went back to check it again, the junction/bracket turned freely when I loosened the mounting bolt...

Offline robvangulik

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Re: Brake master cylinder rebuild kit
« Reply #23 on: August 23, 2020, 09:23:34 PM »
You probably forced it on its place by screwing it on the first time ;)

Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #24 on: August 23, 2020, 10:14:58 PM »
So, going to try bleeding the system tomorrow, keeping in mind all the advice above.

But: when doing this, do I need to have the rubber MC diaphragm in place at all?  Or is that just to keep the fluid under control when the bike is in use?

Offline robvangulik

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Re: Brake master cylinder rebuild kit
« Reply #25 on: August 23, 2020, 11:58:15 PM »
It does the same while bleeding the system, fluid can spritz out and ruin your paint, always wise to cover the tank with a cloth...

Offline mattsz

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Re: Brake master cylinder rebuild kit
« Reply #26 on: August 25, 2020, 10:46:23 PM »
Well, I think I managed bleeding the system.  Filled the system with fluit, got the MC working and bled until no more air came out, either from the bleed nipple or from the return hole inside the MC reservoir.  Not sure exactly how it's supposed to feel, or what the "correct" lever travel should be, as the brakes were frozen when I got the bike.  But the lever works, it stops the wheel spinning and allows it to spin again when I release the lever.  The brake light switch works.

Anyone care to comment on lever travel?  How far before the brake light comes on?  How far from the grip does the lever really harden up?  I'm sure there must be variations from bike to bike, but nice to have an idea.

I've got the lever pulled back to within about 1/2 inch of the grip and tied overnight, just in case it helps draw more air out...

 

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