fast

The car in question has 70K miles and brakes and transmission fluid has never been changed.

The brake light sign lit up the other day "brake pads are at minimum" with no squealing or any pulsations on braking. Do I replace just the pads or rotors too? Shall i consider machining the rotors or just buy a new set?

Transmission :

Replace just the pan or shall I go all the way and get the mechatronic sleeve and seal and all that? Adaptations ?

Any good videos to DIY for the above and good store to order the parts?

Thanks

donpb

Replace the pads. It's not recommended to machine rotors on BMWs. My e60 has 140k mi, I have not done the mechatronics, YMMV.

twh

Measure the rotor thickness. They have a minimum thickness beyond which you need to replace them.

fast

Have you changed the fluid at all, dropping and replacing the pan/fluid?

What's the minimum thickness and do I need to change the brake sensor too?

twh

2007 530i

Front brakes:
Rotor diameter: 324 mm
Minimum thickness (should be stamped somewhere on the brake disc): 28.4 mm

Rear brakes:
Rotor diameter: 320 mm
Minimum thickness (should be stamped somewhere on the brake disc): 18.4 mm

If you change pads, you need to change the brake pad sensor.

donpb

No.

ZeroDfx

With 70k miles, I doubt your rotors have been previously replaced, so I'd go ahead and install new rotors and pads, along with new sensors. You can buy complete rotor/pad/sensor packages from various BMW online suppliers like FCP Euro, Pelican Parts, Autohaus AZ, Parts Geek, etc. You can get pkgs. for either just the fronts or rears, or fronts and rears together. I'd be inclined to do the whole thing, front and rear.
Good luck.

fast

Changed the pads/sensor and not the rotors which felt smooth without any edges. The caliper brackets were bitch to install but was able to put them back on. Bought a Motive bleeder and be changing the fluid this weekend

twh

PSA on Motive Bleeder...the hose does not last forever. After a few years it burst one me while under pressure spraying brake fluid everywhere. Fortunately it was summer and the garden hose was near and I got the brake fluid hosed down before it could become paint stripper. I replaced the hose with some Teflon hose -- not as flexible, but not going to burst.