Hard braking - Keeping her straight

[buzyg]

. . . After you have used the brakes hard crouch down on all fours near a wheel, not a good look, and see if your face can detect if one of the calipers are hotter.

Chuckle of the day - thanks

The poor neighbours.

[dhobbs]

I had a sticking caliper on an old car and you could tell by touching the wheel, it was much hotter than the others!

[Ed Doe]

Sounds like worn suspension bushes causing alterations in toe angles. Check tyres for uneven wear, and look to replace lollipops (front wishbone rear bushes) and rear trailing arm bushes (RTABs) and an alignment as a starter for ten. Be aware that unless the bushes are utterly kippered you really aren't going to be able to check for play by hand - you're best off making a judgement on when to replace them based on the mileage they've done and the type of driving.

[ph001]

Here's a diagram of what Ed is talking about (top of picture is front of car)....

The ones that typically wear are no.3 (front wishbone bushes) and no.4 (RTAB). I would go for Meyle HD as replacements.

A universal bush removal insertion kit is also great for jobs like this ... https://www.ebay.co.uk/itm/Universal-Pr ... .l4275.c10

Z4 bushes.png (200.68 KiB) Viewed 1176 times

[R60BBA]

Here's a diagram of what Ed is talking about (top of picture is front of car)....

The ones that typically wear are no.3 (front wishbone bushes) and no.4 (RTAB). I would go for Meyle HD as replacements.

A universal bush removal insertion kit is also great for jobs like this ... https://www.ebay.co.uk/itm/Universal-Pr ... .l4275.c10

Z4 bushes.png

Cheers fella, that’s handy.

Quick question but how long do bushes last on the Z4? My car has only done 30,000 miles but I was under the impression bushes could last up to 60,000 miles?

[ph001]

Depends on driving style to a degree - 30,000 motorway miles will give them an easier life than 30,000 miles of backroad hooning. They do deteriorate with age as well though so 11 years is about right for replacing.

[cj10jeeper]

I think you're going to end up chasing your tail on this and replacing half the car without proper diagnosis.
If you've done the obvious and checked for disc & pad wear, even contact on discs ie no missed parts in sweep, tyre pressures correct, tyre wear left to right wheels even. All checked on front and rear and done your brake testing on different surfaces, such as a big car park, then I'd take it to a station with an MOT style brake tester and that will in 2 minutes to confirm or eliminate all brake issue. You can then either repair or focus on all the more complex stuff of bushes, alignment, suspension, damaged parts, etc.

IMHO it's nothing to do with calipers sticking as this replicates at all speeds nor collapsed lines as that gives mushy or no brakes. Lollipops are possible, but part 3 first

[R60BBA]

I think you're going to end up chasing your tail on this and replacing half the car without proper diagnosis.
If you've done the obvious and checked for disc & pad wear, even contact on discs ie no missed parts in sweep, tyre pressures correct, tyre wear left to right wheels even. All checked on front and rear and done your brake testing on different surfaces, such as a big car park, then I'd take it to a station with an MOT style brake tester and that will in 2 minutes to confirm or eliminate all brake issue. You can then either repair or focus on all the more complex stuff of bushes, alignment, suspension, damaged parts, etc.

IMHO it's nothing to do with calipers sticking as this replicates at all speeds nor collapsed lines as that gives mushy or no brakes. Lollipops are possible, but part 3 first

Thanks for this, it was quite an insightful read.

Tbh I was planning to replace the discs, upgrade to Red stuff pads and Goodridge lines w/ fluid change next month anyways as I will be taking the car to the Nurburgring in May.

I guess I may have to bring this service sooner. If I still have problems after then I will look at bushes and other suspension components. But I would probably discuss this with my mechanic first before spending £500...

[R60BBA]

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).

[R60BBA]

FYI

Quotes listed above are for labour + brake fluid only.

[ph001]

DS2500 are a well known and recommended pad. I'd rate them over Redstuff but not as good as Performance Friction Z rated pads (0558.11 = front, 0396.11 = rear)

[R60BBA]

DS2500 are a well known and recommended pad. I'd rate them over Redstuff but not as good as Performance Friction Z rated pads (0558.11 = front, 0396.11 = rear)

What do you run on your M3?

[cj10jeeper]

HEL lines are excellent and can.be supplied in any colour

[ph001]

I run the same PF on the M3. They are very low dust as well.

[R60BBA]

I run the same PF on the M3. They are very low dust as well.

Have you got a link for them pal?