master cylinder

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GT380c

master cylinder

Post by GT380c »

hi all

am i correct in thinking that the return hole in the master cylinder should go straight through into the chamber where the piston operates ???

and if so how critical is the hole size ???,

having no joy bleeding it through and cannot think of any other possible issue as the bore is clean, unscored and I have fitted a new repair kit, piston and seals etc..

thanks

john.
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yeadon_m
Posts: 7401
Joined: Sat Jan 02, 2010 7:10 am
Location: Canterbury Kent

Re: master cylinder

Post by yeadon_m »

John,
There are two holes going into the cylinder the piston slides in. One is large and rarely blocks, as it's a wide bore drilling. The other is tiny and appears to have a brass pressed in jet in it, often blocks and yes I would guess it's diameter is crucial to good operation - perhaps the release rate when you let go the lever?
It's too small to get the tip of a needle in it. I would worry at it with a fine wire from the top as well as from inside the stripped cylinder. Worked for me on a horribly blocked 550A master, after which the brakes released as they should.
I've a picture posted somewhere on this forum of that pressed in jet but let me know tomorrow if you need it again
Cheers,
Mike
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GT380c

Re: master cylinder

Post by GT380c »

hi

just a follow up on this issue.

held back the lever 2/3`s in with cable ties. left it for a week and gravity must of took over as it bleed easily..

john
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