funny noise when pulling off

[paulm172]

getting a funny noise which sounds as though its coming from the ns 3/4 area. its ounds like a bang just after the point of pulling off. its not the normal knock on a 172 whne ptting the car into 1st gear but sounds like it comes from the back. doesnt happen with any other gear and only noticed it once when braking harder than normal but at no other time. Any ideas?

 

[badinvincible]

Surface rust on the discs?

Does it only happen when you set off after it's been raining?

 

[paulm172]

no. has only started over th past few days and has been when wet and dry. Discs look ok to me. Its almost like a small bang to try and describe it. Its not like the sound you get with surface rust or deglazing a pad.

 

[badinvincible]

Erm... no idea then.

I used to get the wet disc thing whenever it rained overnight.