Nikon FA hard to open

I have a Nikon FA that I find difficult to get the film back open on. I have to pull up hard on the film winder and even then have to force the back to open. Any suggestions as to what I could do to fix this? thanks in advance.

You could have sticky light seals or the back could be lightly bent.

Check to see if the light seals are tacky and carefully examine the straightness of the back.

Also, a slight warping of the back, either in the middle of the back or on the end that wraps around could cause it to bind against the camera body, not allowing it to spring open when released.

Here is the service manual:

Thanks for the info. I'll check both when I get back to the house.