I watched videos of the C3 bumper replacement. I noticed more than one person using an adjustable wrench to remove the valve stop from the receiver. It seemed to come out very easily.
When I attempted to remove my valve stop I used a 11 mm open end wrench. That should be a lot better than an adjustable wrench. The stop was very tight. The wrench slipped and rounded the corners of the hex end. Of course I was not happy. I just marred my new rifle. I switched to a box end wrench that worked fine.
I replaced the bumper and began re-assembling the rifle. When I attempted to screw the adjuster back on to the stop it would only turn a few degrees. When the wrench slipped it distorted the barrel of the stop. I tried to reshape the valve stop but nothing worked.
Thanks to Utah Airguns, I had a new valve adjuster assembly in a few days.
FWIW
When I attempted to remove my valve stop I used a 11 mm open end wrench. That should be a lot better than an adjustable wrench. The stop was very tight. The wrench slipped and rounded the corners of the hex end. Of course I was not happy. I just marred my new rifle. I switched to a box end wrench that worked fine.
I replaced the bumper and began re-assembling the rifle. When I attempted to screw the adjuster back on to the stop it would only turn a few degrees. When the wrench slipped it distorted the barrel of the stop. I tried to reshape the valve stop but nothing worked.
Thanks to Utah Airguns, I had a new valve adjuster assembly in a few days.
FWIW