Wah Pedal Gradual Volume Loss

[Roctopus]

Hello friends,

I was asked by a friend to take a look at his Landgraff wah pedal. He told me that when it was engaged there was a significant volume loss. I did some initial research and it was suggested that it could be the footswitch so I replaced it. Afterwards the pedal worked great. However after about a few minutes of playing the volume would gradually reduce. Not sure what else to check. Any help would be greatly appreciated. Let me know if pictures are needed and I can post some

Roctopus

[ian_guga]

check the caps ...