Instability under braking

[javam]

I had to do some hard braking in my G yesterday and I am a bit concerned about how lively the rear felt.

It seemed very unstable and almost felt like it was going to step out at one point. I am struggling to remember another car I have owned that exhibited this sort of behaviour so it must have been many years ago and almost certainly a result of worn out bushes on the sheds I used to drive.

As this is a fairly new car (4000 miles) and I was braking on a straight and dry road I am thinking of getting it checked out, but I just wondered if anyone else had experienced anything similar in their G?

It did it once before, not long after I picked it up, but I put it down to a greasy surface and ABS at the time.

Thanks

[Tirreni]

Mine has been very stable.

[JFT89]

I've had a couple of scary moments braking but the car has never felt unstable during, sorry cant be more help.

[paulmacs]

My Brera did this to me on a couple of occasions. But not the G. Mine seems very stable.

[javam]

Thanks for the feedback guys.

I will have a look for anything obvious, but I suspect it needs brake balance check so I will speak to the dealer.

[JamesL]

Like you said, could be a brake imbalance, or maybe your fluid has managed to absorb some water, and led to other issues?

Also, what cars have you come from?

[AGT21]

In the past I have found tyre type and wear can have a big influence, particularly in front wheel drives. Some tyres when very worn can snake all over the place depending on the camber of the road.

[KrisW]

Check your tracking. You may have inadvertently whacked one of your rear wheels against a pothole and put it out of line.

[javam]

Thanks for the input.

Water absorbtion in the fluid seems unlikely, as it is only 3 months and 4000 miles old.

Tyre wear appears normal, and on the rears minimal as you would expect for fwd and the mileage.

As for whacking a pot hole, not impossible, but as I said, it did it not long after I picked it up and that not long was when it had 15 miles on the clock.

As for previous cars 18 in 20 years, but most recently, mk 6 golf, b8 a4, e39, e90, GTV, all perfectly stable, even under very hard breaking round the ring in the GTV.

[rossifumi46]

I thought the same on Saturday but it was the 1st day of ownership and was in Dynamic mode braking at about 80mph...just not used to it i guess and hoping

[javam]

Interesting, maybe it is just a bit twitchy.

[JamesL]

What speed were you braking from and to?

[davidjwbailey]

tried 30-0, 50-0, 60-0 and 80-20 today (Red Brembos). Car was nailed to ground. No squirm.
then got it to squirm coming into a roundabout at about 60 and finding a Lotus appear from under a hedge ;-) so stamped on it, on a downhill curve and rough road surface. it felt squirmy but just ... stopped

[diarx]

You've obviously checked your cold tyre pressures?

Mine brakes flat as a pancake btw - had to make an emergency stop in the wet on a downhill cement road (no tarmac) a couple of months back, was gobsmacked by how hard it pulled up compared to my previous cars with ABS.

[Maningrey]

I have found mine to be a bit twitchy when braking hard in D - was hard as hazards came on! Only got 4000 miles on mine as well.

Maybe it is D mode with the pre fill and the brembo's in QV do the job a lot better.

They did the job which is the main thing i guess

[Sami951]

Surely the ESP would prevent rear actually stepping out? I would say the combination of somewhat sporty suspension and good brakes might well cause a nervous feeling when braking hard (lots of weight transfer from the back to the front tires) and even more so if braking was not done in a straight line.

Was it pulling clearly to one side or the other, or just generally feeling twitchy? My guess is that if it was pulling to either way then maybe the alignment or brake balance can be off.. if just twitchy, then wouldn't really worry about it.

[agenta lusso]

Downhill curve would alter the weight distribution even more to loading the front more, dont worry alls fine !

[micsanderson]

I can report I had to stop today from 40 to 0 left me peeling my face off the screen, was in a staight line though on a dry road, and my first thought was that the car behind me couldn't possibly stop that quickly, and i was right, he swerved and went round, stopped about half my car length forward of my rear down the side of me! That el do.