Vibration under breaking

Gwest44 · Post by **Gwest44** » Fri Dec 21, 2018 5:36 pm

Stopping performance doesn’t appear overly compromised but the vibration is that significant I’ve got to the stage where I need to get it sorted.

Any recommendations on what I should purchase would be appreciated - fitting will be via a local independent I use to service all my cars

buzyg · Post by **buzyg** » Fri Dec 21, 2018 5:40 pm

First thing is to get your tyre balance checked. I nearly wrecked a new set of pads and disks simply because of a small imbalance in a tyre.

greg81 · Post by **greg81** » Fri Dec 21, 2018 5:45 pm

Warped brake discs maybe

Silverzedtom · Post by **Silverzedtom** » Fri Dec 21, 2018 6:46 pm

Could be a number of things, I’d check:

None of your callipers are sticky
Alignment is ok (tyres worn unevenly?)
Wheel balancing
Bushes
Worn out suspension components.

If it’s not obvious it shouldn’t take a mechanic long to find the problem

Gwest44 · Post by **Gwest44** » Fri Dec 21, 2018 6:48 pm

Had the balancing and alignment do a few weeks back but will get it down to the garage and ask him to check breaks and suspension to determine what needs attention - thanks all

Gwest44 · Post by **Gwest44** » Fri Dec 21, 2018 6:57 pm

If it is the discs does £750 sound right for a set of 4?

Smartbear · Post by **Smartbear** » Fri Dec 21, 2018 7:03 pm

I remember reading that bmw were cheapest for M brakes a while ago, I must admit to being surprised at that!
Rob

Gazza51 · Post by **Gazza51** » Fri Dec 21, 2018 9:30 pm

I recently bought a pair of OEM rear discs for £168 from BMW dealer inc p+p

Mike. · Post by **Mike.** » Fri Dec 21, 2018 10:18 pm

My money would be on a caliper piston on the way to seizing up, it takes a lot to warp a disc these days. Especially one the size of the Z4M with the cooling and venting etc.

I had the same, a grumbling vibration under braking that didn’t really affect performance. Turned out to be a sticky front right caliper. Had both fronts refurbed and it’s been perfect since

Spaniarduk · Post by **Spaniarduk** » Sat Dec 22, 2018 1:18 am

Get oem disks amd pads and when you order mention the fact that in the internet forums people are buying them from other bmw dealers with massive discounts inclusive of shipping. All this is in fact true. Do your research. I did that last summer and i got my front ones at about 40% discount from my local BMW dealer. It turns out you can haggle at BMW

Wildfire · Post by **Wildfire** » Sat Dec 22, 2018 1:31 am

I had this a few times. I changed the discs and it went away for a bit.

Basically it was a seized piston that caused warped discs (on the new ones).

Check the calipers by seeing if the disc is hot after driving.

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