Saturno rear brake master cylinder rebuild kit

[Rangy]

I'm having problems with the rear brake on the Saturno 500 IOM.
I have bled it a few times, but it won't bleed properly.
Pressure can be gained by a few small pumps on the lever and it is fine, but if left for 2 weeks it needs pumping again to get pressure. Yesterday the piston jammed fully in. That was easily fixed by pushing out from the banjo end and bleeding again. Now it is fine but I am thinking the rear master cylinder needs a rebuild?
There are no markings on the rear master cylinder. Does anyone have a link to a rebuild kit, or let me know the make of master cylinder if I need to replace?
Thanks,
Rangy

[Joachim]

sometimes those brake pumps tend to wear out. Due to some water causing rust.
So bying a repair set may last some time, or not
New pumps are rather hard to find.

50mm bolts distance, 11mm piston
Maybe this one is still available
Usually it isn't

https://www.stein-dinse.biz/product_inf ... _id=216253

Also some Nissin pumps are adaptable.

you may search here for:

Saturno Bremspumpe and use some kind of translation tool. Deepl?

ciao Joachim

[Rangy]

Thanks Joachim, I was able to order the replacement cylinder so hopefully that will work out.

[Joachim]

keep us informed

Joachim