17R3W
Posts: 7
Joined: Sat Aug 03, 2019 6:50 pm

Break service needed already? 2017 Rex with under 37,000 km

Mon May 24, 2021 6:30 pm

I got my winter tires off recently (because it's almost June, so it's about time) at my local ford dealership.

I got this note "Noticed front brake getting low, (see quote)

Recommend rear brake service."

(As far as I can tell there is no quote)

Why/how?

Breaks should last the better part of 80,000 km, even on non electric BMW's.

Also, I pay for that stupidly expensive BMW recomnded maintenance (at the BMW dealership, ford only does my tires), what am I paying for if my breaks need repair?

I'm going to call the BMW dealership (there isn't one local, closest one is an hour away) and see what they say.

Anyone have any idea what might have happened? Has anyone needed premature break repair?

Pahaska
Posts: 77
Joined: Thu Jul 30, 2020 11:49 am

Re: Break service needed already? 2017 Rex with under 37,000 km

Mon May 24, 2021 7:14 pm

Disc brakes occasionally drag due to the pad not sliding away from the disc so that there is a slight drag. The drag may not be noticeable to the driver, but, long term, there will be excessive wear, I check my hubs occasionally with an IR thermometer to ensure there are no problems.

alohart
Posts: 2401
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Break service needed already? 2017 Rex with under 37,000 km

Mon May 24, 2021 8:25 pm

17R3W wrote:
Mon May 24, 2021 6:30 pm
I got this note "Noticed front brake getting low, (see quote)

Recommend rear brake service."
Huh? A front pad is getting thin, so this mechanic recommends rear brake service! That doesn't make much sense. You might ask this mechanic to clarify what he wrote. Maybe he meant to write that he recommends front brake service.

The right rear and left front pads have wear sensors that trigger a warning when the brake pads need replacing. However, if the left rear or right front brake caliper is sticking such that the pad is dragging, a warning wouldn't be triggered. The brake wear sensor system assumes even wear on left and right brakes which is typical.

If you're concerned, you might ask a mechanic to check the right front or left rear brake for excess wear because wear on the other brakes would trigger a warning.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

spartacus68
Posts: 87
Joined: Sun Jul 09, 2017 11:07 am

Re: Break service needed already? 2017 Rex with under 37,000 km

Wed May 26, 2021 10:33 pm

I changed the front a rear discs and pads on my wife's i3 REx with original BMW parts. This was at 52k miles (2016 model). It's not just brake rotor or pad thickness. We live in Scotland, so we had a pretty harsh winter, lots of road salt and grit, and it all takes its toll.

The rotors can develop grooves, or a lip, corrosion. Rather than trying to resurface, it's more economic just to switch them out. Good opportunity to do a brake fluid change too (every 2 years), and check and lubrucate the brake sliders. I replaced the sensor cables, as the original ones although not tripped due to pad wear were worse for wear.

Also an opportunity to check the caliper, dust sleeves. Corrosion on the caliper that can swell the dust sleeve is a common issue. Ultimately it's a safety issue, so you can't put a price on that.
2015 i3 REx, 60ah, solar orange. Reversing camera, leather interior, sunroof, park assist, professional navigation.

17R3W
Posts: 7
Joined: Sat Aug 03, 2019 6:50 pm

Re: Break service needed already? 2017 Rex with under 37,000 km

Fri May 28, 2021 6:13 pm

Update:
I spoke with the BMW dealership, and they are indicating that my breaks were fine in August and not to worry.

I was 7mm on the break pad, and they can't see how I would be in need of a replacement already.

They also advised that a sensor would tell me if I was too low. At that point I would have about a month to get the pads replaced.

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