Spent some more time disassembling parts to get them ready for zinc-replating.
Thought while at it, i could take the brake-parts for a replating as well. So i started with the disassembly of my Sumitomo MK63 Solid disk type Ex-works type calipers:

First got the old pads and shims removed. still looking quite good to be honest:

Then spent an hour or so at the garage and disassembled the rest of the calipers. With the help of my trusty little air-compressor and some redneck-skills i managed to get 7/8 cylinders out of the calipers without any damage to me, tools or the calipers.
However the last sucker doesn't want to come out. Even brought it to a local garage and he used a torch to heat it up but wasn't able to remove it. we'll see how i can do that. Any inputs? Otherwise i'll try another two days having it soaked in WD40, and if that doesn't work i'll bring it to a machine shop or so...

Otherwise i was quite successfull, the brakes are in great condition and by the way even learned a lot about brakes (first time working on some brakes so that was quite some fun). 
After that i took all the bits from the brakes plus some other i found in my garage and put them in the "re-plating box". Still need to clean all of this stuff for a few hours before i can send it there (they prefer old rust, grease, rubber-leftovers and paint to be removed.

Hope i find some time again soon..

6 hours ago, JDMjunkies.ch said:

Any inputs?

You could reinstall the other piston with seal and hold it in with a C clamp, plug one of the holes and install a grease fitting/zerk and pump it full of grease until it pops. As long as you burp it for air the stuck piston shouldn't explode out the way it does with compressed air.

I did same way what grannykont express using grease to remove piston.

https://motofaction.org/mechanical-101/a-how-remove-stuck-seized-brake-pistons-with-grease-gun-rust/

 

17 hours ago, grannyknot said:

You could reinstall the other piston with seal and hold it in with a C clamp, plug one of the holes and install a grease fitting/zerk and pump it full of grease until it pops. As long as you burp it for air the stuck piston shouldn't explode out the way it does with compressed air.

 

16 hours ago, tamo3 said:

I did same way what grannykont express using grease to remove piston.

https://motofaction.org/mechanical-101/a-how-remove-stuck-seized-brake-pistons-with-grease-gun-rust/

Thanks for the input guys. I never got the idea to re-install the other piston and use a c-clamp. Will try that first with air (after having soaked it in rust-removal oil for another night or so) and see if it works. I guess the grease-pump is the next thing if it doesn't work. but it will mess up all the air-channels then. I know it's cleaneable but still another step to take. so i'll try it with air first.
Thanks a lot. really appreciate your knowledge

Can you push the piston in farther, to break the bond?  Easier to push it in mechanically first.  Once it's loose it probably won't take much to pop it out.

4 hours ago, Zed Head said:

Can you push the piston in farther, to break the bond?  Easier to push it in mechanically first.  Once it's loose it probably won't take much to pop it out.

Exactly, I was thinking if the mechanic applied heat there may not be any seal in there anymore, just carbon.

15 hours ago, Zed Head said:

Can you push the piston in farther, to break the bond?  Easier to push it in mechanically first.  Once it's loose it probably won't take much to pop it out.

Carefully hammering the piston deeper into the calipers using a wooden hammer was easy, but it won't come out anymore. Anyhow. i will try again later with some of the inputs mentioned before

While i can't show you much, i've been busy lately completeing a lot of stuff i've started but never really finnished.
1) Thanks to the input of some readers i was finally able to remove the last cylinder from the brake caliper. The solution was easy. install the allready-removed cylinder again and fix it with a c-clamp. add some air-pressure again to the brake-fluid channels and it would pop out easily (It doesnt look like the cylinder is aligned properly but i fixed that)

 

Since sunday my Rattler / Vibrator / Tumbler / Spirator / Whatever you call it, has been working in full force to remove all the rust / Paint / Dirt and grease from all the parts i will send for re-plating. It's maybe not the fastest solution but it comes out quite handy and you don't have to do anything except of waiting

 

Guess it will take another week or so until all the parts are ready andsome of them even might need a bit of manual cleaning, but the first bunch of parts are allready looking shiny and have a super-smooth surface

 

Then i got some new (used) turn signal switches from my mate Patrick (Thanks for that!) to complete that job too.  

That's it for now hope for more updates again soon

Doesn't look terrible.  Looks like maybe it had a collar of rust catching the edge of the piston, holding it in.

I had a thought, that doesn't help you now but might someone else.  I think that you could have blocked the brake line and the bleeder holes then filled the cavity with a low compressibility fluid, like water, oil or grease, and then pressed the other piston in with the C-clamp to generate pressure.  Or popped it with a hammer.  Just a thought about another way.  If you pop it with a hammer you'd get a much faster pressure increase so leakage wouldn't be so significant.  And the stuck piston would fly a lot farther when it came out.

Was quite busy this week with the Z's small projects that have been going on. I've been cleaning and exchanging the partsi n my tumbler almost daily and today i finally had them completed:


Now all is packed up and ready for zinc re-plating and yellow passivating. Which means i have to wait for the parts for approximately one week before i can continue.
Pretty happy with the result by the way. The Tumbler was well invested money. just took me some years to figure out how to use it properly


During preparation process i also fixed some parts which where slightly worn out.
Like this one. Before:


Straightening it out in the little vice:


and After. Much better


Oh and then got some new parts, like the replacement repair-lamp bulb cover. I know it's not 100% the OEM colour, but it looks pretty good. still might try to clean the original one.


Oh and some new door switches by the original manufacturer:


And greased and packed all my brake-stuff to prevent them from rusting.


Oh and started disassembly and cleaning of the ignition switches:

Next step: Ordering some parts (will do that in a minute) and then complete some other bits next week.

7 hours ago, JDMjunkies.ch said:

 

Was quite busy this week with the Z's small projects that have been going on. I've been cleaning and exchanging the partsi n my tumbler almost daily and today i finally had them completed:


Now all is packed up and ready for zinc re-plating and yellow passivating. Which means i have to wait for the parts for approximately one week before i can continue.
Pretty happy with the result by the way. The Tumbler was well invested money. just took me some years to figure out how to use it properly


During preparation process i also fixed some parts which where slightly worn out.
Like this one. Before:


Straightening it out in the little vice:


and After. Much better


Oh and then got some new parts, like the replacement repair-lamp bulb cover. I know it's not 100% the OEM colour, but it looks pretty good. still might try to clean the original one.


Oh and some new door switches by the original manufacturer:

Where did you find those ?

7 hours ago, JDMjunkies.ch said:

 

 

2 minutes ago, Namerow said:

just took me some years to figure out how to use it properly

And exactly what have you learned, please?