Canon P light leak / curtain travel issue

[Flatlands]

Hi all!

My Canon P leaks small amount of light in 'released' shutter curtain position. It's not much usually, but if the light shines into the lens, it's visible on the photo as a bright streak near the edge of the frame. My bet is first curtain travels too far or second curtain stops too shortly. 1mm adjustment in curtain travel length would possibly solve the issue.
I'm able to medicate that temporarily when I move the first curtain break lever (in repair manual it's sheet no. 10, part C9057, the break assembly sits under the bottom plate of the camera), but it goes back slowly to original position and after a couple of shots it's back to how it worked before.
Ideas so far:
1. The break should not move by itself, I somehow should be able to adjust it's position and fix it permanently, not sure how to do it or why it moves back.
2. One of the curtains has slightly wrong dimensions
3. There is a way of adjusting travel of one of the curtains that I'm not aware of.

Any ideas are welcome. I'm moderately comfortable taking the shell and bottom covers out, top is much harder. I don't want to mess more without a good solution. Repair manual is available online, so at least I have one trouble less to deal with.

It's the only issue I have with this body, the issue is small, but it bothers me that I have to use lens cap all the time. Otherwise it's totally fantastic. Times are accurate, film transport is precise, rangefinder is adjusted, it works smoothly. Even the old selenium meter works totally fine.

 

[Peter Jennings]

It sounds to me like the shutter just needs a good cleaning. Making adjustments to a shutter without thoroughly cleaning first could make the problem worse. I would disassemble, clean and rebuild. Most likely, everything would work fine afterwards.

Best of luck!

 

[mooge]

Off the top of my head (I've replaced a curtain on a VI-L, but it was a while ago) -

1. Closing curtain isn't closing fully
- Likely issue with slow speeds escapement pallet disengagement mechanism (looking down the lens throat, gear and lever to the right of slow speeds escapement)

2. Botched repair job
- Curtain overlap is incorrect - check overlap with shutter partially wound. Should be around 1,5...1,7 mm
- Shutter drum winding gears timed incorrectly?


If the camera's never been opened before (check for scratches on fasteners) I'd guess it's #1. The opening curtain doesn't have much to do with keeping light out when the shutter's fired; it's more of a 2nd curtain thing. So something is preventing the 2nd curtain from closing fully.



Well that's what I think anyways...

 

[Shac]

I sen my P to Youxin - he did a great job

 

[ForestCap]

http://www.rangefinderforum.com/forums/showthread.php?t=160858

Read replies in this thread, might help.

 

[Flatlands]

Thank you all!

For the curious ones, here is a sample showing the leak:
https://www.flickr.com/photos/otherdreams/36098003156
It was toned down a fair bit, but it's the vertical streak close to the right edge of the frame.

Indeed it's a problem with the second curtain and whatever is close to it. Just as mooge wrote 🙂
I've checked, the curtains overlap by 1.8-1.9mm when winding, so I think it's all OK here. I believe the shutter foil was changed not long ago (it has almost no crinkling).
I've flushed the escapement with lighter fluid, it seems like there was no lubrication there so this was my safest bet. It was rather clean, but you never know. As a result the shutter started to sound 'zippy', the gear next to the second curtain roller was making the noise. Also the second curtain travel was even shorter and random. It got better (but not entirely OK) after lubricating the zippy wheel. I think, if it's good or bad, I have to live with what I have, I can't think about anything more I could do.
Best wishes to all of you! Thanks!