Hi everyone,

I'm a new member but I've had this site bookmarked for a while now and I'm happy to have found such a great resource for analogue photography. I've been shooting film for about three years and recently jumped into medium format with an RB67 last year.

The problem I'm having with it, though, is when I release the shutter the film lever won't let me advance to the next frame, I have to manually push the switch (with the arrow) on the rear of the back before advancing the film.

I've done some digging into what the problem could be, and I discovered that when the shutter is released there is a pin that fires from the body into the top right corner of the back which flips the red flag and allows the film to be advanced. This pin on my body gets stuck and doesn't fully eject. I've tried moving it in and out manually (to loosen the pin) and it will function properly for 3 or 4 frames but then get stuck again.

Does anyone have any thoughts on how I can keep it working? I know this is a really technical issue so if anyone needs further clarification, I'll be happy to do so.

Thanks,

My guess would be some lube has dried out or a tiny spec of crud in the pin channel is causing the sticking. My suggestion would be a tiny bit of a penetrating lubricant like Breakfree CLP, WD-40 or other penetrating oil. Do not apply directly to the pin, that would flood it and might cause more problems. Apply the penetrant to a cotton swab and lightly run the tip of it around the pin to get just a very small amount on the pin. Work the pin in and out several times then wipe off the excess and work the pin some more. You don't want to "lube" the pin per se, just work enough penetrant into the pin channel to soften and break up the dried lube or crud causing the sticking and free it back up again. It is better to apply too little penetrant rather than too much; repeat if need be until the pin moves freely.

Thanks, houdel. I'll give it a try.

Welcome to the world of analog photography here at APUG and this Mamiya RB67 forum as well. You did not mention what camera body you have. The reason I mention this as it might help when narrowing issues. It has been years since I used a Mamiya RB67 Pro body and film holder. But, I thought that was normal when using that setup, meaning having to push the rear lever before film advancing. Maybe my setup back then had the same defect at the time and I was unaware.
I've used my Mamiya RB67 ProSD body and film holder for 20+ years now and it operates differently and without a rear release to move before advancing the film. The ProSD back does have a small lever to operate to allow or prevent multi-exposures. The Pro back I had to be careful with as it would allow multi-exposure all the time. So the habit of once the shutter was tripped I'd hit the release lever and film advance lever immediately.
I'm curious as to what you find out, keep us posted.