I have a Penn 4500-SS. Acquired it when I bought a bunch of gear at an estate auction. Appears moderately used but well cared for. Works fine except that the bail is very touchy, it closes as soon as you cast. Sometimes it is difficult to even get it to stay open, there is no audible click. I'm willing to open it up to take a look, just wondering if there's something specific I should look for, or if this is a common thing. thanks---
here is your schematic. https://www.mysticparts.com/Assets/images/pennparts/schematics/4500ss.pdf
i'm not familiar with the trip mechanism, but it's obviously allowing the bail to close too easily. it's supposed to catch and hold until the rotor turns. something is worn out or loose. hard to figure out without the reel in hand. please keep us posted.
I'm assuming it is similar to the 550SS that I have. It's just one screw on the rotor arm to remove the cover, and then you can see everything. It's probably just full of gunk, it's a spring that cams over that holds the bail.
Bail wire may be bent out of shape, not allowing bail to open fully. Mystic Reel Parts has a picture of a new bail wire (item 24 in parts list) if that helps.