it makes a clicky/scratchy noise whenever it reaches the down position and touches the button.
Hi Lee
I don't think this a cap/DC problem as it would show up as you move the pedal up and down, not just when the pedal reaches the down position.
It may not even be the pot... unless there's a crack in the carbon track. So let's see if we can determine if the pot is at fault.
First thing to do is lift the pedal up, then toggle the bypass footswitch up and down just to determine there's nothing wrong with it... make sure you've got signal going thru it.
Then remove the base plate and with signal going thru the wah, tap the circuit board with the handle end of a screwdriver and see if you hear the "clicky/scratchy noise"
The next thing I'd do is remove the geared bar that drives the gear on the pot.
Note: Before you do this, put a mark across where the pot gear and the pedal gear meet so you know where to put it when you reassemble it.
Now with signal going thru it, rotate the pot with your fingers and see if you still get the "clicky/scratchy noise". If you don't then you need to look elsewhere.
Is the pot soldered directly to the circuit board or it it connected with wires?
If it is connected directly to the circuit board then it could be an intermittent solder connection on the circuit board that's being stressed when the pedal bottoms out.
Can you post some pics of the inside of the pedal... might make it easier to figure out what the problem is.
Try the above and report back with your results.
Hope this helps