48 replies to this topic

[Andrew aka Stuwy]

[CHILL Gone DUTCH]

Have you got a front splitter stuwy

[Andrew aka Stuwy]

Yes. Why?

[TheRealVXed]

Maybe as metal heats up it doesn't always uniformly expand across the surface?  The hotter the discs get the greater the disparity between the big bits and the little.  This could cause the shake and explain why it gets worse the harder you work the brakes?

 

Just a thought though, could be something else

 

I used to get this though, changed my discs recently and didn't notice it on Sunday so may have got lucky

 

 

[mbes2]

It's definitely from the front?

[Andrew aka Stuwy]

It starts with steering wheel wobble and get progressively worse till the whole car shakes. So I assume so

[Bargi]

Ping Duncanf, I remember years ago going out with him and identical problem, not sure what he did to sort it.

[Andrew aka Stuwy]

Ping Duncanf, I remember years ago going out with him and identical problem, not sure what he did to sort it.

 

will do

[Duncan_F]

Brake fluid.

 

That's what my problem was, and it sounds like you have all the same symptoms I had. When I checked, my fluid it was all rank and crusty and had flaky bits in it.

 

On the road I never noticed I had a problem. On track though, as soon as it got up to temperature I had the same symptoms you're having.

 

I flushed the system through thoroughly (to get rid of all the flaky gunky rubbish) and then replaced it with some upgraded brake fluid.

 

Problem sorted. 

[Andrew aka Stuwy]

my brake fluid is 5 days old

[Claws]

Did you purge the ABS when you changed the fluid?

[mbes2]

Only happens once hot... on track or road also ?

 

Only under braking hard ? with no symptoms unless on brakes.

 

 

[TazN]

Stuwy have you taken the pads out and checked them? I haven't had any problems on my 1144s and despite only having done 2 track days in them I haven't had any issues with them. Gave them a fair bit of abuse at Woodbridge as well.

 

Bearings should be easy enough to check if you whip them off. Though I wouldn't of thought they'd cause it only when hot. I take it the wobble is at all speeds on track or is it more prolific at higher speeds?

[Andrew aka Stuwy]

Brake fluid was done by BoT while I was drinking tea and being a nuisance. I have not got the car hot enough on the road. I Don't drive fast on the road. It's repeated heavy use that makes it happen after a couple of laps. No symptoms other then shaking and only on the brakes. It was worst when braking from 120+

[Andrew aka Stuwy]

Not taken the pads out. I need some pins as BoT used lock wire last time

[TazN]

Once it's cooled down does it disappear until up to temp again? - Either between sessions or at the end of the day on the drive home did it go?

 

Is the shuddering being felt through the steering wheel or through the seats and chassis?

[techieboy]

Have you not effectively identified the problem already? If the pads are fouling the disc at a certain point in it's travel, then the disc is either warped or you've got a hefty pad deposit on the face of the disc. What caused it, is the question? As it's the front, possibly holding the car on the brakes when the discs were properly hot or maybe the hub face wasn't properly cleaned before new discs were fitted causing run out. Either get your discs skimmed whilst fitted to the car, or given how cheap standard discs are, replace them and make sure the hub face is clean and not damaged before fitting.

[Andrew aka Stuwy]

I never put the brakes on and hold them. Even if there cold. The pads are about 50% anyway so I'll change them too before the national. Taz to answer your question. Just driving through the pits slowly was enough to cool everything so I had 2 or 3 good braking zones before the shake come back. Starts in steering wheel and get progressively worse to whole car shake.

[drunknmunky]

Definitely sounding more and more like warped discs to me, or as techie says, maybe hub face crap causing run out. I warped a set of rears on my rx7, that started as only when hot did I feel anything,and a gentle roll for a minute or 2 sorted it, but repeated use gradually made the problem worse to the point is was whenever I pressed the pedal, hot or cold. Mine was caused by a sticking caliper overheating the disc, then when parked it stayed on and warped it.

[fezzasus]

Both discs and hubs are cheap. I think you should eliminate any of the causes by changing both.