Rear Master Cylinder breather/return hole

[Guest]

I'm attempting to rebuild the rear master cylinder and caliper and replace the 3 piece brake line with one Goodrich line. I'm waiting on OEM parts for the caliper and MC so I'm doing the clean-up now. I dipped the parts in Berryman's for 12 hours.

Below is a close-up of the MC, there's nothing inside the top hole, it's completely empty/clean from edge to edge. I'm assuming the bottom hole is what I've read is the breather or return hole. With a tiny wire I can move something around in the bottom hole, like a very small bearing or something. It doesn't feel like gunk and I haven't gotten aggressive with it to remove it.

Is there a bearing or something restricting that's in that bottom hole?

[Agemax]

have you removed all the gubbins from inside the M/C? if you haven't then you are hitting the spring or plunger with the thin wire.
with all the internals removed the hole should be clear and you should be able to see it from the inside

[btbarb]

have you removed all the gubbins from inside the M/C? if you haven't then you are hitting the spring or plunger with the thin wire.
with all the internals removed the hole should be clear and you should be able to see it from the inside

Yes, all the internals are out. I can completely go through (and all around) the top hole and see it inside the MC, but not the bottom hole.

[cowboyup3371]

Then yes there is still gunk inside. Keep poking with your wire and spray brake cleaner in there

[Agemax]

Yes, all the internals are out. I can completely go through (and all around) the top hole and see it inside the MC, but not the bottom hole.

it must have something blocking it unless the wire you are using is to thick to go through the hole

[btbarb]

Yes, all the internals are out. I can completely go through (and all around) the top hole and see it inside the MC, but not the bottom hole.

I was able to get a small wire through the bottom hole and see it inside, but the hole the wire went through is a hole in the center of a small bearing like thing that rotates freely in that bottom hole. Sound right?

[Agemax]

I was able to get a small wire through the bottom hole and see it inside, but the hole the wire went through is a hole in the center of a small bearing like thing that rotates freely in that bottom hole. Sound right?

dont sound right to me,i thought it should be just a clear hole. but i may be wrong..............

[btbarb]

dont sound right to me,i thought it should be just a clear hole. but i may be wrong..............

Ok, I think I got it, thanks guys.

Optical illusion or old eyes. Whatever was rotating in there must have been foreign, nicely rounded, and centered, it's out now. For future reference, that bottom hole has shallow bowl like shape to it on the inside and a hole about the size of a bread twist tie wire in the bottom of the bowl.

[Agemax]

Ok, I think I got it, thanks guys.

Optical illusion or old eyes. Whatever was rotating in there must have been foreign, nicely rounded, and centered, it's out now. For future reference, that bottom hole has shallow bowl like shape to it on the inside and a hole about the size of a bread twist tie wire in the bottom of the bowl.

glad its sorted, those bread twist wires do have their uses, good for poking jets out as well

[btbarb]

For future reference, here's a shot of the breather/return hole all cleaned out.