Braking problems

[Clgale88]

Had a squeking from my front brakes for ages so the old man took them apart to clean and copper grease but noticed the passenger side had worn down loads compared to the drivers side aswell as the pad has come away from the metal slightly. What's causing the wearing more and pad coming away?

 

[mat-nos]

my guess is a sticky caliper on the side that has worn the most or one that doesnt work very well on the side that hasnt worn as much....
what brake pads are they??

 

[KEVRSI]

I'd say sticking slider on the caliper , the rubber boot has probs gone