e70 X5 Brake DIY Question.

[evilution915]

My rear brakes are squealing like mad. Indy shop says it's the rear pads.
I called a few places, they do pads + rotors at the same time.
They say if they do pads only, it'll potentially warp. Any truth to it? Or is it a money grab.


And in case anyone searches. Here are links for the DIY:
Brake pads only:
http://www.xoutpost.com/bmw-sav-foru...70-brakes.html

Brake pads + rotors + sensors. (This is to e53)
http://www.xoutpost.com/articles/x5/...e-job-diy.html

Apparently it's the same as e70, except you need one special socket
http://www.xoutpost.com/bmw-sav-foru...ement-e70.html

[Thirdy]

if the rotor is still at specification, there is no need to replace. Just replace the pads. Replacing just the pads will not warp the rotor.

[evilution915]

Originally Posted by Thirdy

if the rotor is still at specification, there is no need to replace. Just replace the pads. Replacing just the pads will not warp the rotor.

I'll look at thickness. The minimum is stamped on there right?
Reading more, I found that rear pads can be used twice per rotor at least. (of course it varies by driver).

Thanks for input guys. Maybe I'll make a diy video

[JCL]

There is more to it than the remaining rotor thickness, although that is a good place to start. You need to evaluate the surface finish of the rotors, look for hot spotting, and so on. Many times it is possible to reuse rotors, whether front or rear. Many of us don't do so, because it isn't worth our time to have to go back in and do the brakes again if we get pad noise after not replacing the rotors. There isn't a lot of meat on BMW rotors (likely due to a decision to reduce unsprung weight). You can't turn them, which used to be standard practice. If they get too thin, you will have problems, probably more to do with increased brake fade than with warping.

Many shops (including dealers) replace rotors as standard practice due to their desire to reduce service warranty redo whereby customers come back and ask the shop to redo the brakes because of squealing post pad change.

[rh71]

While under warranty, the dealer wouldn't do my rotors, but just replaced the pads, so there you go. They said the rotors were still in spec and gave me numbers.

Here's that thread: http://www.xoutpost.com/bmw-sav-foru...-question.html

[Thirdy]

Originally Posted by JCL

There is more to it than the remaining rotor thickness, although that is a good place to start. You need to evaluate the surface finish of the rotors, look for hot spotting, and so on. Many times it is possible to reuse rotors, whether front or rear. Many of us don't do so, because it isn't worth our time to have to go back in and do the brakes again if we get pad noise after not replacing the rotors. There isn't a lot of meat on BMW rotors (likely due to a decision to reduce unsprung weight). You can't turn them, which used to be standard practice. If they get too thin, you will have problems, probably more to do with increased brake fade than with warping.

Many shops (including dealers) replace rotors as standard practice due to their desire to reduce service warranty redo whereby customers come back and ask the shop to redo the brakes because of squealing post pad change.

No, not all dealers replace rotors. I have had 2 instances where my e60 needed a brake pad replacement and I tried to insist that they also replace the rotors but they said it is still within spec. Same thing with my E70 when pads were replaced again I tried to tell them to replace the rotors too but NOPE they didn't replace it. So it's not always the case that everytime you replace brake pads that the rotors also need to be replaced.

[JCL]

Originally Posted by Thirdy

No, not all dealers replace rotors. I have had 2 instances where my e60 needed a brake pad replacement and I tried to insist that they also replace the rotors but they said it is still within spec. Same thing with my E70 when pads were replaced again I tried to tell them to replace the rotors too but NOPE they didn't replace it. So it's not always the case that everytime you replace brake pads that the rotors also need to be replaced.

Sorry, my meaning wasn't clear. Many shops, including many dealers, replace rotors as standard practice. I am sure there are some that don't. Mine does, but offers pad replacement with and without rotor replacement for those that want that.

I just think it is good practice to replace the rotors. You can often get away with not doing so. There will be an increased chance of brake pad noise due to the surface finish of the used rotor, and reduced brake performance (ie more propensity to fade) due to the thinner rotors not having as much thermal capacity. But it can certainly be done in many cases.

[edennelson]

Originally Posted by Thirdy

No, not all dealers replace rotors. I have had 2 instances where my e60 needed a brake pad replacement and I tried to insist that they also replace the rotors but they said it is still within spec. Same thing with my E70 when pads were replaced again I tried to tell them to replace the rotors too but NOPE they didn't replace it. So it's not always the case that everytime you replace brake pads that the rotors also need to be replaced.

I believe he is saying the dealer routinely replace rotors instead of turning/machining them. Rotors do not necessarily need replacing when you need pads. Rotors wear slowly and need to be machined or replaced usually because of warping rather then wear.

[Kormaster]

if rotor has enough life.. just change pad only and bed them in...

[WWONG]

Hmm mm?