More rear braking problems w the GS 650

[Sarcvicious]

I started fiddling with the rear brake again. The leak that was coming from the plastic diamond part of the yoke isn’t leaking anymore, but now the boot is. This is a brand new OEM boot. It doesn’t sound air tight, and as we all know air in brake lines is no good. Any suggestions on how to remedy? My picture turned sideways for some reason. I’m pointing to the problem area.

486003F8-35F5-4D37-86A1-EF664C45350F.jpg

[chuck hahn]

Only way fluid can get into the boot is if the cups on the piston is leaking. May have a tiny bit of crud caught when you reassembled them??? Could just be time for a rebuild kit......is whats in there now new?

Only takes a speck to make a leak.

[Sarcvicious]

Only way fluid can get into the boot is if the cups on the piston is leaking. May have a tiny bit of crud caught when you reassembled them??? Could just be time for a rebuild kit......is whats in there now new?

Only takes a speck to make a leak.

Thanks for the response. I was actually just looking at a rebuild kit thinking maybe there are other components I need to swap. I’ll get on that now.

[Sarcvicious]

Ok I’m utterly confused right now. I have the rebuild kit which of course comes w no instructions.


im
assuming the old piston is seized up inside up I’m not sure how to get it out or if The old one is really where I ever think it is. For the part that is sitting on the needle nose tool, is this where an old piston/spring would be? It looks like a single piece to me, but I’m confused how the rebuild pieces would fit in to the yoke.

So do I try to remove the piston w the compressed air? I’m not able to get higher than 20 PSI when I usually need 50 or 60 psi

DA603ACE-063D-4E5C-928E-31CF978E07EB.jpg

[Sarcvicious]

Not getting any traction on this post.

Any idea if there’s someone I can send this part off to, or would someone be able to lead me to a new part? I’m assuming there’s a piston stuck in this piece. I can’t get it out, and I’m not even quite sure I’m attempting to get it out correctly.

[Gorminrider]

suzuki-gs650g-1981-x-usa-e03-rear-master-cylinder_big3IMG00902968_45a0.jpg

The pictures are small but you seem to have it all apart so what "piston" are you looking for that you can't get out?

[Sarcvicious]

I can’t get the spring go go inside of the yoke. When I disassembled it, there was no spring goes against the parts diagram you posted. I’m guessing there’s an old spring stuck inside but I don’t know how to get that part open

[Big T]

Did you remove the circlip?
Part #7

[Gorminrider]

yes, Reference the diagram. What # is this "can’t get the spring go go inside of the yoke" .....?

Can you see something down inside the cylinder? if someone has somehow pushed the circlip all the way down inside the brake cylinder, it will be very difficult to get it out without scratching the cylinder....making an Assumption that has happened, if it's even possible I guess I would:
A)try first to leave it alone if it's at the very bottom and doesn't block any holes (the piston cup is never supposed to "bottom out" so all it would do is add a bit of spring tension)
B)make a protective sleeve of thin plastic to protect the cylinder while I tinkerated with tinytools trying to get it out...a dremel with a very long bit (diamond dental burr?) might be able to cut it
C) start browsing ebay if A and B are fails

[Sarcvicious]

Sorry guys. I’ve been caught up w the holidays. Part number 2 is stuck inside the yoke. Yes I removed the snap ring. I didn’t realize my pictures were coming in so small.

the rebuild kit came w a new piston. The piston sits in the part that I was calling the yoke (it’s the portion above part #2 on the diagram).

Im not getting enough PSI on the air pump that I used to get the pistons to come out on the calipers. So I’m not sure if there’s something else I can try or if there’s any suggestions on how to go about getting the “piston cup set” out so I swap it with the rebuild piston cup set.

if my pictures were actually viewable this would be a much clearer description.

[Big T]

You have a common problem
If you can't get enough PSI out of your air compressor, maybe you know someone that does.

Or, a grease gun that screws into the output

[Sarcvicious]

Ok so we got an awesome air compressor and it’s still not coming out so I think we’re going something wrong. I uploaded my photos to a hosting site so they’re viewable. The rebuild kit didn’t come w instructions,
so I laid the parts out how they go. The last photo is the “cup” that I think we’re trying to get out but now I’m questioning whether that even comes out or not. If it doesn’t, I have no idea where the replacement spring is supposed to go.

https://ibb.co/FVzq3t1

https://ibb.co/x3h4zn5

https://ibb.co/gJVrRQf

[Cipher]

galvanic corrosion and or varnish from dried up partially moist stagnant brake fluid.?

Short of using a dangerously high pressure ebay or a machinist

[Cipher]

Ok so we got an awesome air compressor and it’s still not coming out so I think we’re going something wrong. I uploaded my photos to a hosting site so they’re viewable. The rebuild kit didn’t come w instructions,
so I laid the parts out how they go. The last photo is the “cup” that I think we’re trying to get out but now I’m questioning whether that even comes out or not. If it doesn’t, I have no idea where the replacement spring is supposed to go.

https://ibb.co/FVzq3t1

https://ibb.co/x3h4zn5

https://ibb.co/gJVrRQf

Hard to see but it look like there's a ring in a groove in the hole
If so it can't be driven out from the back
Can you tap the core plug back using a hardwood dowel ?

[650Skull]

Wrote a comprehensive answer and the auto save didn't save the info and deleted my answer before i replied when i was looking for some confirming info..................This site has some bad features.........Sorry i can't write it again.

Basically the piston looks to be still in there.