[BlackE93]

hey guys my brake change date is coming up soon and was wondering what will be changed? im new at all of this so was wondering if ill need to change everything or just the rotor?

[fenixxishot]

Just the rotor huh? I'm just a little worried now.

[BlackE93]

Originally Posted by fenixxishot

Just the rotor huh? I'm just a little worried now.

sorry im new to all this and was just wondering what needs to be replaced when the time is up?

[idrift4wd]

Originally Posted by BMamba

sorry im new to all this and was just wondering what needs to be replaced when the time is up?

Well for brake maintenance, the brake pads and rotors will need to be replaced. If your trying to save money, more likely then not, you only need to replace the pads. Replace rotors if they are too thin, are warped, or when braking gets shaky. + front and rear brake sensors (yes you need these)

a brake fluid flush would be a good idea if you never have done it before.

[fenixxishot]

Ill try to be more helpful. You don't necessarily have to replace the rotors but you should buy a micrometer to measure the thickness to verify they don't need to be replaced. Pads are not that expensive and if you are mechanically inclined they are not impossible to swap.

[BlackE93]

Originally Posted by idrift4wd

Well for brake maintenance, the brake pads and rotors will need to be replaced. If your trying to save money, more likely then not, you only need to replace the pads. Replace rotors if they are too thin, are warped, or when braking gets shaky. + front and rear brake sensors (yes you need these)

a brake fluid flush would be a good idea if you never have done it before.

thank you for the reply

[BlackE93]

Originally Posted by fenixxishot

Ill try to be more helpful. You don't necessarily have to replace the rotors but you should buy a micrometer to measure the thickness to verify they don't need to be replaced. Pads are not that expensive and if you are mechanically inclined they are not impossible to swap.

that very helpful thanks

[Efthreeoh]

Okay, so hopefully you're not trolling here, but from your question you have no clue as to how brakes work and have heard the term "rotor" and that it is somehow related to brakes. So to educate you on the subject, here is what you need to know about brakes when you take the car in for replacement of them.

There are basically six components to the system:
Brake Pads - consumable - two (2) for each brake
Brake Rotor - consumable - one (1) for each brake
Brake Fluid (hydraulic oil) - consumable
Brake Caliper - repairable if required
Brake Master Cylinder - repairable if required
Brake lines - repairable if required

Brakes use hydraulic force to apply a friction material (the Brake Pads) against a cast iron disk (the Brake Rotor) that is attached to the axle. The hydraulic force is applied to the pads by the Caliper, which clamps the pads against the rotor (think of it as grasping a dinner plate if the dinner plate is in the vertical position). The hydraulic force is applied to the Caliper by your foot pressure on the brake pedal, which pushes a piston in the Master Cylinder. Pads are the friction material and are designed to be consumed and are generally what is replaced during a brake job. Rotors are also designed to be consumable, but generally not at the same rate as the pads. Hydraulic brake fluid is meant to be reguarlary replaced (every 24 months) as it collects water and dirt and becomes less effective in transfering the hydraulic force to the caliper.

For BMWs my advice is to replace the brake pads and rotor as a set because generally the rotor doesn't last all the way through the life of the second set of brake pads and may get too thin and warp over time.

Any independent BMW repair shop can provide brake service at a less price than the dealer.

[Saintor]

For BMWs my advice is to replace the brake pads and rotor as a set because generally the rotor doesn't last all the way through the life of the second set of brake pads and may get too thin and warp over time.

At 70000km I skipped the rear rotors and and just replaced the pads; it looks like that the rear rotors will make it at 130-140K km without issue.

This morning for the first time after 5.5 years 116700km of crazy traffic, I am replacing my front brakes (pads and rotors). I am impressed with the brakes of E90.

[reck]

Originally Posted by Saintor

At 70000km I skipped the rear rotors and and just replaced the pads; it looks like that the rear rotors will make it at 130-140K km without issue.

This morning for the first time after 5.5 years 116700km of crazy traffic, I am replacing my front brakes (pads and rotors). I am impressed with the brakes of E90.

On that note.. does anyone have the OEM rotor thickness thresholds?

[Saintor]

22.4mm

EDIT: My job was complicated this morning.

The main problem was removing the 2 18mm bolts that holds the pads carrier.

I have limited access since my car is not raised. I broke my 3/8" ratchet. I have a long 1/2" drive bar but again limited access.

I finally went to an hardware store and bought a few tools, including closed 18mm key, a propane torch. I manned-up, swore and finally got those bolts. Not exactly easy when the car is not on a lift.

[ndukyh]

Originally Posted by Efthreeoh

Brakes use hydraulic force to apply a friction material (the Brake Pads) against a cast iron disk (the Brake Rotor) that is attached to the axle. The hydraulic force is applied to the pads by the Caliper, which clamps the pads against the rotor (think of it as grasping a dinner plate if the dinner plate is in the vertical position). The hydraulic force is applied to the Caliper by your foot pressure on the brake pedal, which pushes a piston in the Master Cylinder. Pads are the friction material and are designed to be consumed and are generally what is replaced during a brake job. Rotors are also designed to be consumable, but generally not at the same rate as the pads. Hydraulic brake fluid is meant to be reguarlary replaced (every 24 months) as it collects water and dirt and becomes less effective in transfering the hydraulic force to the caliper.

For BMWs my advice is to replace the brake pads and rotor as a set because generally the rotor doesn't last all the way through the life of the second set of brake pads and may get too thin and warp over time.

Any independent BMW repair shop can provide brake service at a less price than the dealer.

[BlackE93]

Originally Posted by Efthreeoh

Okay, so hopefully you're not trolling here, but from your question you have no clue as to how brakes work and have heard the term "rotor" and that it is somehow related to brakes. So to educate you on the subject, here is what you need to know about brakes when you take the car in for replacement of them.

There are basically six components to the system:
Brake Pads - consumable - two (2) for each brake
Brake Rotor - consumable - one (1) for each brake
Brake Fluid (hydraulic oil) - consumable
Brake Caliper - repairable if required
Brake Master Cylinder - repairable if required
Brake lines - repairable if required

Brakes use hydraulic force to apply a friction material (the Brake Pads) against a cast iron disk (the Brake Rotor) that is attached to the axle. The hydraulic force is applied to the pads by the Caliper, which clamps the pads against the rotor (think of it as grasping a dinner plate if the dinner plate is in the vertical position). The hydraulic force is applied to the Caliper by your foot pressure on the brake pedal, which pushes a piston in the Master Cylinder. Pads are the friction material and are designed to be consumed and are generally what is replaced during a brake job. Rotors are also designed to be consumable, but generally not at the same rate as the pads. Hydraulic brake fluid is meant to be reguarlary replaced (every 24 months) as it collects water and dirt and becomes less effective in transfering the hydraulic force to the caliper.

For BMWs my advice is to replace the brake pads and rotor as a set because generally the rotor doesn't last all the way through the life of the second set of brake pads and may get too thin and warp over time.

Any independent BMW repair shop can provide brake service at a less price than the dealer.

thanks for taking the time to type that and im seriously clueless when it comes to this kind of stuff i just wasent sure what will be replaced when i go in for the replacement.

[Saintor]

Originally Posted by Saintor

22.4mm

For the record, I measured with a micrometer the actual thickness of my 72000 miles front rotors.

22.4mm = 0.882"

One was at 0.800-0.805" and the other was at 0.815-0.817". Neither one were pulsing.

If I was changing pads earlier and that thickness > 0.882" I think that would leave the disk alone!

[GoRomeo]

This past weekend I changed my rear rotors and pads for the first time thanks for the DIY here and some videos. As posts above said, change your rotors along with pads since the rotors are not going to make it through the second set of pads. I changed only the pads over 2 yrs ago. This happened to me.

One thing that backed me up was the rotors NOT coming off the hub since but only due to my error since I forgot that your shifter has to be in N and not in P in order to rotate the rotors and hit them with hammer all around. Honestly not understand what efect this causes since my ebrake was not active. Anyways I greased all the brakets and added brake quie to my pads and everything is working good. Hope this helps. Total cost in parts was 147.00

[Saintor]

Originally Posted by GoRomeo

One thing that backed me up was the rotors NOT coming off the hub since but only due to my error since I forgot that your shifter has to be in N and not in P in order to rotate the rotors and hit them with hammer all around. H

Just wonder.... do mechanics use heat to remove a rotor stuck on an hub? Any risk to damage bearing?




It is not the 1st time that I hear that the rear rotors can be hard to remove.
My front ones came off easily, though.

[NormE91]

I would be afraid to use heat for exactly that reason. Others may disagree. I've always been able to get them free without heat, even on very old cars.

[GoRomeo]

Originally Posted by Saintor

Just wonder.... do mechanics use heat to remove a rotor stuck on an hub? Any risk to damage bearing?




It is not the 1st time that I hear that the rear rotors can be hard to remove.
My front ones came off easily, though.

I have to say that was user error on my part since I did not place shifter in N before I tried this. Mine was in P (park) and thats why I had a hard time removing it. Once I was able to turn rotor and hit it the regular hammer it started to come off loose. The other side came easy since I did it right. It was a little stucked but was able to take it apart after turning it with my hand and hitting it with hammer around.

[Blackhawk36]

Originally Posted by Saintor

At 70000km I skipped the rear rotors and and just replaced the pads; it looks like that the rear rotors will make it at 130-140K km without issue.

This morning for the first time after 5.5 years 116700km of crazy traffic, I am replacing my front brakes (pads and rotors). I am impressed with the brakes of E90.

I am doing my fronts next month. My 2007 335i will have 90,000 miles. That is over 145k km. I am inpressed to.