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Discussion Starter #1
It goes without saying that BMW brake jobs are expensive. Phrased charitably, the BMW Service Centers are - how might I put it... aggressive? conservative? safety-conscious? - in what they choose to replace. There may not be a need to replace brake rotors (especially back ones). There may not be a need to replace sensors. SCs replace it all, from what I'm told.

BMW is new to this eDrive business. Toyota has been at it for much longer..

Now, a funny little quirk of the Prius/HiHy/Lexus Toyota world is that you don't actually need to change your brake pads very often. The more "hybridishly" you drive a Toyota hybrid, the less you need pads. Rotors, of course, last forever. It's another benefit of regenerative braking. Prius pads can last for a decade, based on pad depth alone. Many people change them once in a while, just on principle.

Which begs a question: what's the merit of a $2300 brake overhaul on an eDrive X5 40e, 300e, or any other BMW eDrive variant? Seems to me that maybe a $300 set of pads would be useful every 3-5 years, just on principle. But the whole fleet is pretty young. Nobody's made it that far yet.

Would not that 4x$2300 investment be better spent on, say, a new battery pack at 8 years than on rotors every two?

Anybody have data on this yet? Has anybody actually needed pads on a 40e, or did you just replace them based on wall-calendar, or dealer habit?
 

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I can't think of a reason to change brake pads "just because." Change them when they get to a minimum thickness that you don't want to exceed. Same with rotors. They have a minimum thickness engraved into the edge, and there's no need to replace them until they get close to that, unless they are checking or cracking.

Probably more important to flush the brake fluid every couple of years than change pads or rotors for the heck of it. Just my opinion.
 

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I'm almost afraid to ask but why the question and what makes you think that you need to have a $2300 service on a schedule? And why do you think the brake pads on the 40e are any different than the pads on a 35i? I don't understand why you feel that eDrive has to do with the brake pads.
 

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Discussion Starter #6
I'm almost afraid to ask but why the question and what makes you think that you need to have a $2300 service on a schedule?
Good question. Well, I got quotes on the BMW extended warranty. :\

That started it. The quotes had a lot of zeros. Too many zeros. I'm trying to explain to my wife (gal-in-a-car?) why I should write a huge check now on the extended warranty and/or service plan, to pay for stuff years from now.

That, and I've been reading post-after-post here on Bimmerfest about how expensive the brake jobs are, and how the inclusion of the brake job makes the BMW extended maintenance plans worth the price, and how there seems to be a need to "flush the brake fluid" every two years.

Here's a brief sample:

http://www.bimmerfest.com/forums/showthread.php?t=894669
http://www.bimmerfest.com/forums/archive/index.php/t-889547.html

And why do you think the brake pads on the 40e are any different than the pads on a 35i?
I don't think the pads are any different. I'd assume they're exactly the same BMW OEM part. But...

I don't understand why you feel that eDrive has to do with the brake pads.
That's the nub of it. eDrive has everything to do with brake pads. When you "brake" in a hybrid, you're really using the rotating fields of the electric motor (inside the ZF transmission) as a de facto generator, creating drag farther down the driveline, slowing the wheels from turning.

https://www.zf.com/corporate/en_de/magazine/magazin_artikel_viewpage_22065960.html

It's like that experiment you did back in middle school science, where a motor becomes a generator, and you can actually transmit power from one motor to an identical one via a shaft:

https://www.youtube.com/watch?v=oiIVkp7mMwE

In the case of the ZF transmission, you're not using two identical motors. That's just the middle school demo. You're actually using the ZF electric transmission stator in lieu of brake pads. Or in addition to brake pads, if you're doing spirited driving.

So the upshot is that when you're regenerative braking, you're not necessarily using brake pads (or rotors, or brake fluid, or the master cylinder, or pads) at all. I spent about five hours in New Jersey rush hour traffic this week, crawling along using ACC/MAXeDrive/EcoPro, which is unspeakably awesome, BTW. It's like having a chauffeur. Every time ACC slows the car, the battery goes up. Every time ACC speeds up the car, the battery goes down. But the brake pads don't get used at all, or not much. The car just follows the one in front of it, like a little electric dogsled dog would. Very cool.

I could see going 10 years on factory pads in a 40e. Which begs the question: why do I need "service" on brakes at all? The rest of the "service" is just changing the hydraulic fluid and bleeding the system, just like you'd do an excavator or ZTR lawn mower.

Accepting the premise, above, that there's infinite "shelf life" if pads aren't too thin, and that rotors are stamped with minimum thickness, then this fancy-schmancy brake job is just a fluid change, and might stay that way for 5+ years.

Honestly, what started all this is that I'm noodling on the value of the warranties and extended maintenance plans, while my car is still new(ish).
 

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Good question. Well, I got quotes on the BMW extended warranty. :\

That started it. The quotes had a lot of zeros. Too many zeros. I'm trying to explain to my wife (gal-in-a-car?) why I should write a huge check now on the extended warranty and/or service plan, to pay for stuff years from now.

That, and I've been reading post-after-post here on Bimmerfest about how expensive the brake jobs are, and how the inclusion of the brake job makes the BMW extended maintenance plans worth the price, and how there seems to be a need to "flush the brake fluid" every two years.

Here's a brief sample:

http://www.bimmerfest.com/forums/showthread.php?t=894669
http://www.bimmerfest.com/forums/archive/index.php/t-889547.html

I don't think the pads are any different. I'd assume they're exactly the same BMW OEM part. But...

That's the nub of it. eDrive has everything to do with brake pads. When you "brake" in a hybrid, you're really using the rotating fields of the electric motor (inside the ZF transmission) as a de facto generator, creating drag farther down the driveline, slowing the wheels from turning.

https://www.zf.com/corporate/en_de/magazine/magazin_artikel_viewpage_22065960.html

It's like that experiment you did back in middle school science, where a motor becomes a generator, and you can actually transmit power from one motor to an identical one via a shaft:

https://www.youtube.com/watch?v=oiIVkp7mMwE

In the case of the ZF transmission, you're not using two identical motors. That's just the middle school demo. You're actually using the ZF electric transmission stator in lieu of brake pads. Or in addition to brake pads, if you're doing spirited driving.

So the upshot is that when you're regenerative braking, you're not necessarily using brake pads (or rotors, or brake fluid, or the master cylinder, or pads) at all. I spent about five hours in New Jersey rush hour traffic this week, crawling along using ACC/MAXeDrive/EcoPro, which is unspeakably awesome, BTW. It's like having a chauffeur. Every time ACC slows the car, the battery goes up. Every time ACC speeds up the car, the battery goes down. But the brake pads don't get used at all, or not much. The car just follows the one in front of it, like a little electric dogsled dog would. Very cool.

I could see going 10 years on factory pads in a 40e. Which begs the question: why do I need "service" on brakes at all? The rest of the "service" is just changing the hydraulic fluid and bleeding the system, just like you'd do an excavator or ZTR lawn mower.

Accepting the premise, above, that there's infinite "shelf life" if pads aren't too thin, and that rotors are stamped with minimum thickness, then this fancy-schmancy brake job is just a fluid change, and might stay that way for 5+ years.

Honestly, what started all this is that I'm noodling on the value of the warranties and extended maintenance plans, while my car is still new(ish).
Thats a nice explanation of regenerative braking (I really really love your posts btw. Please keep contributing to this section of the forum!).

I dont have an answer to your question as it relates to 40e but I can tell you that BMWs use condition based service, so things dont get replaced every XXXX miles, but "when the car asks for it". Because the E cars use regenerative braking, slowing the car without using the pads as much, I would guess that brake job would be pushed waay out, for the reasons you stated.

Brakes dont get done at 36k or 50k miles but when the pads are worn past a certain point. That "certain point" will likely be pushed way out because of the regenerative braking, but it still depends on your driving style. If you are thinking about buying the extended warranty and paying for it with a brake job, I feel that would be a losing bet in your case.

Of course there are other things that might go wrong and these cars are expensive to fix outside of warranty (and no telling about the e cars with the battery etc.. kinda why we never considered keeping my wifes Active Hybrid 5 she had). I just think banking on getting a brake job in there to pay for it would not necessarily pay off in a car that uses heavy regenerative braking. It may not even pay off in a car that doesnt use that, if the person is not one who is aggressive with the brakes all the time.
 

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Brake fluid needs to be flushed/changed every two years regardless of driving or brake system. This is normal on any car as the fluid will absorb impurities over that period of time. Assuming you are replacing pads and rotors on all four corners it will cost about $1200 in rotors and pads alone. The rest is labor. You could get cheaper after market parts or do it yourself but you're unlikely going to need to replace everything at once anyway. There is nothing special about the 40e brakes and as you point out the regenerative braking may extend the life but ultimately it depends on your driving style. My wife will go through pads twice as fast as I do but that's another story :)
 

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Add'l service coverage BMW Ultimate Care + Accessory

For those who are concerned about the uncertainty or cost of brake R&R for their BMW X5 40e ... check out the accessory option in the build your own page at BMWUSA.COM
 

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Brake fluid needs to be flushed/changed every two years regardless of driving or brake system. This is normal on any car as the fluid will absorb impurities over that period of time. Assuming you are replacing pads and rotors on all four corners it will cost about $1200 in rotors and pads alone. The rest is labor. You could get cheaper after market parts or do it yourself but you're unlikely going to need to replace everything at once anyway. There is nothing special about the 40e brakes and as you point out the regenerative braking may extend the life but ultimately it depends on your driving style. My wife will go through pads twice as fast as I do but that's another story :)
Do they change the brake fluid automatically when you bring the car in? on my 2013 I dont remember them telling me they had to change the brake fluid (I had a 3 year lease) but its possible they just did the service and I did not pay attention.
 

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Do they change the brake fluid automatically when you bring the car in? on my 2013 I dont remember them telling me they had to change the brake fluid (I had a 3 year lease) but its possible they just did the service and I did not pay attention.
Some manufacturers do first brake fluid change after 3 years, then after that every 2 years. Rule of thumb is every 2 years even if you car was in garage all the time.
 

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IRC, all my BMWs had brake fluid changed based on the CBS indicator every two years with the first change within 1,200 miles.

It's worth noting that brake fluid is still covered as part of the normal maintenance coverage for 2017MY vehicles.
 

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Its funny, none of my Ford or Ram trucks ever had their brake fluid changed in the first 4 years as part of recommended service. Every 2 years seems extreme.
 

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Discussion Starter #16
Yep, the Honda Pilot is every 3 years. BMW is on the more frequent side. Not sure why. It's just hydraulic fluid.

Okay, I think I've got a handle on how this should be dealt with.

Over the car's life, it's some mix of BMW SC maintenance; then independent repair shops later, perhaps. So there's a back-of-the-envelope actuarial calculation I'll need to make about the risk/cost of these kinds of repairs vs. the extended warranty plan.

Thanks everyone. I appreciate the feedback.
 
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