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Hard braking - Keeping her straight

Discuss problems you have had or are having with your Z4
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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Sat Mar 10, 2018 6:42 pm

Just a further update.

Did some more testing today and noticed that the offside rear is stepping out a bit under hard braking, which is making it harder to keep her straight. (Thus, this is the fulcrum of the problem methinks).

It’s almost like it goes into a mini slide before I have to catch it again, and align correctly. Kind of like torque steer but whilst braking if that makes sense.

I tried braking hard at speed on different roads and got more or less the same results. However I noticed that it only happens from 70mph upwards, if I brake hard at 40/50/60mph there are no issues.

When I parked up I had a look at my discs and noticed that the offside rear has a groove/cut on the top (see attached) but none of the others seem to have this.

Was wondering if this could be causing the problem?

I’ve booked the car in with BMS Leatherhead for its brake upgrade in a couple weeks.
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Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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Ed Doe
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Hard braking - Keeping her straight

Post by Ed Doe » Sat Mar 10, 2018 7:43 pm

That machined indent in the disc is normal and iirc is to mark the minimum thickness of the disc after which it needs replacing. Entirely normal and if you look hard enough it'll be on all the discs.

My money is still on worn bushes and poor alignment!
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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Sat Mar 10, 2018 7:51 pm

Ed Doe wrote: Sat Mar 10, 2018 7:43 pm That machined indent in the disc is normal and iirc is to mark the minimum thickness of the disc after which it needs replacing. Entirely normal and if you look hard enough it'll be on all the discs.

My money is still on worn bushes and poor alignment!
I did the 12 and 6/ 9 and 3 o’clock check and there was very minimal play. I’ll get BMS Leatherhead to inspect the bushes for reassurance but they seem fine.

The car had a fresh set of tyres and full alignment last month so it can’t be that.
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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cj10jeeper
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Hard braking - Keeping her straight

Post by cj10jeeper » Sat Mar 10, 2018 8:51 pm

At least you’re narrowing it to a possible rear brake issue
I thought those machine marks are factory balancing of the disc? Perfectly normal though
Your pulling left is you compensating for the brake induced rear steer. My instinct is a rear brake refresh will fix it so hold on until this work is done and see the results.
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patriot66
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Hard braking - Keeping her straight

Post by patriot66 » Sat Mar 10, 2018 9:23 pm

That machined indent on the edge of the disc is definitely factory balancing. To be honest with you although there is a fair bit of metal left in them I don't think those discs look in particularly brilliant condition :(
I'd fit some new discs and pads and bet it makes a world of difference ! I fitted new Brembo discs and pads all round on mine a few weeks ago as I was having all sorts of issues with the MTEC/Red Stuff combo I was running. Now the Brembos have bedded in the difference is night and day....much, much better ! :thumbsup:
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Hard braking - Keeping her straight

Post by BMWZ4MC » Sun Mar 11, 2018 5:39 pm

R60BBA wrote: Fri Mar 09, 2018 3:19 pm Okay so after calling around I’ve got a few quotes for replacing discs, pads, lines, sensor and fluid.
  • Munich Legends - £700 :? but £220 if I don’t change lines
  • Evolve Automotive - £327
  • TWG Automotive - £200
  • BMS Leatherhead - £180
  • ETA Motorsport - £250
  • Birds BMW - £350
Interestingly Will at TWG did not recommend using EBC Redstuff pads nor Goodridge lines, stating that the pads have poor bite and the lines can leak. Instead he recommended using Ferodo DS2500 pads and HELL lines. (I presume he notified this to me because TWG provide a 1 year warranty on all work done by them and so need to be satisfied that the parts they fit are up to standard.)

Anyone had any issues with EBC Redstuff? Or should I take his advice and go with the Ferodos.

(I believe the difference in price between the 2 pads is roughly £100).
I use DS2500 on my RS4 and they are a very effective way of stopping 1800kg from enormous speed (with the OEM Brembo BBK). I've not taken it on a track but it stands up to very hard use on country lane blasts.
I use EBC Bluestuff in my ///M and I've found them perfect for track and road use. Previously I used Yellowstuff and found I could overheat the pads on tight technical tracks.
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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Mon Mar 12, 2018 1:52 am

patriot66 wrote: Sat Mar 10, 2018 9:23 pm That machined indent on the edge of the disc is definitely factory balancing. To be honest with you although there is a fair bit of metal left in them I don't think those discs look in particularly brilliant condition :(
I'd fit some new discs and pads and bet it makes a world of difference ! I fitted new Brembo discs and pads all round on mine a few weeks ago as I was having all sorts of issues with the MTEC/Red Stuff combo I was running. Now the Brembos have bedded in the difference is night and day....much, much better ! :thumbsup:
What was wrong with your Mtec/Redstuff combo if you don’t mind me asking.
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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Hard braking - Keeping her straight

Post by jack07 » Mon Mar 12, 2018 9:05 am

Hi R60,My threepenneth on this is listen to Ducklakeview,as those front lower wishbone bushes may not appear worn and may be entirely passable at m.o.t.but upgrade them to a polybush and this eliminates the horrible braking wander that ruins these great cars.Then when the polybush bug bites,do change the rear trailing arm front bushes next to tighten things up nicely.Don't be put off the Redstuff pads,as mine have been excellent in every way for the last 20 thousand odd miles,plenty of meat still on them and have not carved into the discs as I expected.There is no discernable wear lip at the disc edge yet so I recommend them and will buy again when the time comes.The only negative I found was the bedding in time being rather longer than usual.Good luck with however you go :thumbsup:
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patriot66
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Hard braking - Keeping her straight

Post by patriot66 » Mon Mar 12, 2018 9:36 am

R60BBA wrote: Mon Mar 12, 2018 1:52 am
patriot66 wrote: Sat Mar 10, 2018 9:23 pm That machined indent on the edge of the disc is definitely factory balancing. To be honest with you although there is a fair bit of metal left in them I don't think those discs look in particularly brilliant condition :(
I'd fit some new discs and pads and bet it makes a world of difference ! I fitted new Brembo discs and pads all round on mine a few weeks ago as I was having all sorts of issues with the MTEC/Red Stuff combo I was running. Now the Brembos have bedded in the difference is night and day....much, much better ! :thumbsup:
What was wrong with your Mtec/Redstuff combo if you don’t mind me asking.
Red Stuff pads are superb but they just completely overwhelmed the Mtec discs and put that much heat into them the NSF and OSR warped. Had them skimmed on the car and a new set of pads and same again ! Had this combo on 2 previous but different cars and the same happened. Once bitten twice shy so maybe I should've known better than to try them on the Zed. I have my doubts that this would have happened with a better quality disc like the Brembos. :thumbsup:
Sterling Grey '03 2.5i SE / Infinitas Supercharger / S.M.G / Hardtop / Gloss Black 162s / Bilstein B4s / 3.0i Brakes / DLV De-Cat & Silencer / Rebuilt VANOS / Sonar 2Xcite Lights / Carbon & Alcantara Trim / M-Sport Seats / ...& Side Covers !

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Hard braking - Keeping her straight

Post by R60BBA » Mon Mar 12, 2018 10:42 am

jack07 wrote: Mon Mar 12, 2018 9:05 am Hi R60,My threepenneth on this is listen to Ducklakeview,as those front lower wishbone bushes may not appear worn and may be entirely passable at m.o.t.but upgrade them to a polybush and this eliminates the horrible braking wander that ruins these great cars.Then when the polybush bug bites,do change the rear trailing arm front bushes next to tighten things up nicely.Don't be put off the Redstuff pads,as mine have been excellent in every way for the last 20 thousand odd miles,plenty of meat still on them and have not carved into the discs as I expected.There is no discernable wear lip at the disc edge yet so I recommend them and will buy again when the time comes.The only negative I found was the bedding in time being rather longer than usual.Good luck with however you go :thumbsup:
Thanks for your input buddy.

I will get BMS to check the bushes when I put her in for brake service. But if the problem goes away after the brake service then I will change the bushes when required.
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Mon Mar 12, 2018 10:43 am

patriot66 wrote: Mon Mar 12, 2018 9:36 am
R60BBA wrote: Mon Mar 12, 2018 1:52 am
patriot66 wrote: Sat Mar 10, 2018 9:23 pm That machined indent on the edge of the disc is definitely factory balancing. To be honest with you although there is a fair bit of metal left in them I don't think those discs look in particularly brilliant condition :(
I'd fit some new discs and pads and bet it makes a world of difference ! I fitted new Brembo discs and pads all round on mine a few weeks ago as I was having all sorts of issues with the MTEC/Red Stuff combo I was running. Now the Brembos have bedded in the difference is night and day....much, much better ! :thumbsup:
What was wrong with your Mtec/Redstuff combo if you don’t mind me asking.
Red Stuff pads are superb but they just completely overwhelmed the Mtec discs and put that much heat into them the NSF and OSR warped. Had them skimmed on the car and a new set of pads and same again ! Had this combo on 2 previous but different cars and the same happened. Once bitten twice shy so maybe I should've known better than to try them on the Zed. I have my doubts that this would have happened with a better quality disc like the Brembos. :thumbsup:
Cheers for the heads up, I was initially going to go for the Brembo’s but noticed that only the fronts were drilled/slotted :?
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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Hard braking - Keeping her straight

Post by ph001 » Tue Mar 13, 2018 5:39 pm

R60BBA wrote: Sat Mar 10, 2018 12:57 pm
ph001 wrote: Sat Mar 10, 2018 9:57 am I run the same PF on the M3. They are very low dust as well.
Have you got a link for them pal?
http://www.ppcgb.com/products/performance-friction-z-rated-brake-pads-055810
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Tue Mar 13, 2018 6:06 pm

ph001 wrote: Tue Mar 13, 2018 5:39 pm
R60BBA wrote: Sat Mar 10, 2018 12:57 pm
ph001 wrote: Sat Mar 10, 2018 9:57 am I run the same PF on the M3. They are very low dust as well.
Have you got a link for them pal?
http://www.ppcgb.com/products/performance-friction-z-rated-brake-pads-055810
Thanks but I just ordered the Redstuff :tumbleweed: :o :roll: :driving:
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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Hard braking - Keeping her straight

Post by ph001 » Tue Mar 13, 2018 6:54 pm

No worries.... it was first page on Google to be fair! For day to day driving the Redstuff should do the job.
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

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R60BBA
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Hard braking - Keeping her straight

Post by R60BBA » Thu Mar 15, 2018 11:06 am

Just got quoted £30 by BMW Borehamwood for front and rear brake pad sensors.

Is there anywhere I can get these cheaper?

Preferably OEM...
Current: 2002 E46 M3
Current: 2004 R53 Cooper S
Current: 2005 997 Carrera S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

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