Brakes question

[2bmws]

Hi guys, used the car today and washing it afterwards I noticed the front drivers side disc is rusty on the surface yet the other 3 aren't I know I don't use it all the time so it does hang about a bit. I felt the inside side of the disc and that feels shiny so to me it's not braking very well on the outside of the disc. Never come across this before and it's left me scratching my head, if the inside pad is working then the outside one should be too. It recently past its mot so should be all good and can't feel an imbalance under braking.
Have you guys got any ideas cheers

 

[colb]

Check that pad is free to slide on its runners on the caliper and not stuck, if the inner is working ok the outer should as well when they are compressed onto the disc. Give it a good drive and do some heavy breaking see if that cleans up the suspect one.

 

[2bmws]

Ok thanks,

 

[Dunkelgrun]

I had this same thing on my driver rear brake rotor. I was changing them all out anyway, rotors and pads. I noticed the pad in question was stuck into the caliper, not sliding. Cleaned out the gunk with a screwdriver then wire brushed the surface. Thin layer of moly grease on the connecting surface of the caliper and pad. Silicone lube on the sliders, bled the brakes, all better now.

 

[colb]

As well as checking the pad for sticking also check out the slider pins that are the caliper retaining bolts undo them and pull them out, clean them and put them back in with a costing of brake grease so the caliper slides when the brakes are applied, make sure the small rubber seals on the bolts are intact and slipped back on they keep dirt out

 

[2bmws]

Thanks very much for the advice

 

[t-tony]

Also worth fitting the slider pins and making sure the caliper can slide right across the length of the pins without any pads fitted just be sure the pin(s) aren't out of alignment.

Tony.