Braking issue in the South West of France

[Bilko]

Drove down to South West France on Friday (but you guessed that) all good except that about 600km in I noticed the car starting to shimmy under braking at high speed. When I say 'shimmy' it momentarily pulled to one side before almost straight away correcting itself. At first I thought it might just have caught a cross wind, but no… At more normal driving speeds it brakes normally with just a very slight judder under hard braking.

Obv I need to get it checked out, but I'd like to embark on my adventure in the world of French auto repairs armed with more than my very, very minimal French - like a plausible idea of what the problem might be.

Given that that the brakes didn't squeal, and there were no grinding sounds or burning smells, nor any signs of leaking fluid, or of the car being held back (far from it), only a minimal amount more dust on the front passenger side wheel, and that caliper was only marginally warmer than the others I'm wondering if it's something like a sticky slider pin or pins causing that brake to come on slightly behind the others and then release slightly later?

Any thoughts on that or other alternative causes gratefully received… oh, and if anyone can recommend a good garage near Lezignan Corbieres

 

[Rockhopper]

Check your front tyre pressures first.

 

[Bilko]

Very worthwhile shout, but had already checked and they're all still what they're supposed to be

 

[colb]

Sounds like a sticking caliper or a warped disc, do you get any pulsating on the pedal when brakes applied you do describe a shimmy.

 

[Bilko]

Hmm… yeah, hadn't considered it being the disc. I'm going to re-check that re the pulsating on the pedal, but I don't think so.

Shimmy is the best word i can think to describe it, but it wasn't a classic shimmy in that the car didn't keep moving about. It pulled to one side momentarily, enough though to move the car sideways, and then almost instantly corrected itself - so it went out and back in and that was it.
The thing it felt most like was when the car suddenly gets pushed by a strong gust of wind from one side - it was windy on the peage, but it wasn't that windy which was why I was leaning towards something sticking.

 

[enuff_zed]

Hmm… yeah, hadn't considered it being the disc. I'm going to re-check that re the pulsating on the pedal, but I don't think so.

Shimmy is the best word i can think to describe it, but it wasn't a classic shimmy in that the car didn't keep moving about. It pulled to one side momentarily, enough though to move the car sideways, and then almost instantly corrected itself - so it went out and back in and that was it.
The thing it felt most like was when the car suddenly gets pushed by a strong gust of wind from one side - it was windy on the peage, but it wasn't that windy which was why I was leaning towards something sticking.

That sounds as though the calliper on the side opposite the direction it pulls in is sticking slightly, so that the other one bites first and pulls it that way before the slow one catches up.

 

[Bilko]

Yeah, that's what I'm thinking too. Except my grasp of the laws of physics is not as good as yours and I was leaning (pardon pun) towards the side it was pulling to being the one that was late in.

Either way, just been out to give it a quick brake test, trying not to recreate some stock footage from every episode of The Persuaders (one for the older members there), and… nothing. Braked straight as a dye every time. So I'm thinking a couple of day's rest in the baking French sun has for the time being at least unstuck whatever was sticking.

Also, the only bit of the car I cleaned before I left was the wheels (yeah, I'm weird) - so maybe next time I won't be quite so enthusiastic with the power hose… something that actually occurred to me mid-clean.

 

[clarker63]

Or it may be the road surface caused this "one off shimmy" if you can't repeat it and there's no obvious pulsating/noises etc.

 

[Bilko]

Maybe. Though I could repeat it out on the autoroute and the next day too. Now though, after a couple of days not being driven, it seems to have resolved itself. Hopefully.