recently i have noticed a "clicking" sound when i apply pressure on my brake peddal on my 95 TS V6.

the sound is coming from outside so i dont think its the actual peddal.
the sound continues as i depress the peddal further. the brakes seem fine and the peddal doesnt seem spongey either.

it only makes the sound once the engine becomes warmer.

anyone got an idea as to what it could be?