I got mine in the 1980s and it was kind of cheap made even back then. I could not afford the $400 Rollei Infrared accessory. As I recall, I had to squeeze the bulb very hard to get it to work.
Crazy that now I have an Infrared release for my Nikon N75 that only cost a few dollars.
I got several bulb relases of different design, including your one. I assume you are operating it the wrong way.
If one holds the bulb between thumb and index finger, even added by the middle finger, the bulb is too elastic to built the maximum force. If on holds the bulb between the palm and the four fingers and thus squeezes the bulb about most of its circumference, much more pressure can be applied.
I got mine out and tried it on a Rolleiflex SL35 sitting in front of me. The bulb still fires the camera, but it still requires a good hard squeeze.
Do you have the plunger adjusted correctly for your camera?
I got several bulb relases of different design, including your one. I assume you are operating it the wrong way.
If one holds the bulb between thumb and index finger, even added by the middle finger, the bulb is too elastic to built the maximum force. If on holds the bulb between the palm and the four fingers and thus squeezes the bulb about most of its circumference, much more pressure can be applied.
I’m pretty sure that’s how I was squeezing it. I’m thinking that mine might be a dud because after squeezing the bulb it did not inflate and return to normal size again.
Actually I prefer bulb releases because they are smoother in operation than cable ones.
So there is something wrong with your sample. The cylinder cap seems only be clicked-on, but I do not see a way of getting it off without risking harm. In this cap there is a tiny hole ventilating the spring space. You might de-clog it with a needle or even drill it. However at my samples the piston moves the same even with hole covered.
Maybe the piston itself got stuck in its cylinder. But as said you hardly can undo the cap.
If you're not stuck on pneumatic remote actuation....I might recommend you look at a mechanical one from Reveni Labs that makes the great, small light meters.
So far it works on everything, except, for some reason...my Noblex 120 film swing lens camera.