Jupiter-12 re lubing.

[GeorgesGiralt]

Hi folks !
Before dismantling a really dirty J-12 in Leica mount, I've Googled a lot and only found a procedure for a Kiev mount J12.
But these lenses are really different when one look at the mounts, and it's the mount that needs re lubing. So I think the DIY info I've got is not accurate for the LTM one.
Any info, help, howto, web page ?
TIA !

 

[Kim Coxon]

I haven't seen the Kiev mount ones, but the relube on the LTM is relatively easy. I haven't added the J12 yet but you might find these on my site interesting. http://pentax-manuals.com/repairs.htm

Kim

 

[GeorgesGiralt]

Hi Kim !
I've seen (and heavilly used the other howto on your site) but the J-12 seems quite different and I do not want to have a lot of trouble.... So if you don't mind putting it online ???*
I had a J-8 making strnage noise when moving, and really hard to focus as the grease was dead. So I dismantled it. I found a strange Circlips (a cut ring with 2 little holes at the two end of the cut). I was wondering what it was and turned the lens down, and got the aperture blades on the table... It took me and hour to remount it, now, I know where this ring goes and what it does... So once bitten twice shy, I won't dismantle the J-12 without having seen the manual.

 

[Xmas]

Georges

Kim may not be able to confirm that all the LTM J12 have the same arrangement. If you take photos it may help others.

Noel

 

[GeorgesGiralt]

Noel,
The only digicrap camera I own is a camphone able to do, at it's best, 640x480 pict....
So I wonder if it will be usefull to others !
But it is a good idea. If I commit to dismantling, it could serve to re build it. (the main problem is that the focussing mount is not in the good thread, it can't focus on infinity when the ring is at infinity. Add the stiff focussing and you're sure it has been dismantled by a two left foot guy ;-) ) This is the reaso why an howto would be a good start.

 

[Xmas]

Before I bought my digital, I had to use a book and pencil. If you can avoid file marking for assembly, nail varnish and tippex corecting fluid can be useful, lots of lens will have been file marked already!

And a missassembled lens can be a problem, some J12 have spacers to hold the fromt and rear assemblies apart, this to optimise the resolution, if will also alter the focal length (slightly). Good luck

Noel

 

[GeorgesGiralt]

Hi !
Good news ! The seller offered full refund stating that the lens was serviced but not checked after servicing. So I won't need to open it ! The original repairer has to redo it's job...
I was worried because the seller was _really_ slow to answer emails. But every thing seems to be in order now. I hope.
Thanks to all !