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YOUR RESEARCHTrackdays, don't forget to check your discs carefully ... - Page 1 - 911/Carrera GT - PistonHeads UK
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Check crack
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Suggestion
Always check crack with an ultraviolet crack testing system.
Trackdays, don't forget to check your discs carefully ... - Page 1 - 911/Carrera GT - PistonHeads UK
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Leading evidence: 'Check crack' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check crack' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Always check crack with an ultraviolet crack testing system.
Trackdays, don't forget to check your discs carefully ... - Page 1 - 911/Carrera GT - PistonHeads UK
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Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
PistonHeads: 1 discussions
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Generation: 20261026T091943Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I thought that these might just do one more trackday ... until I looked again.
If you enlarge the image towards the top left and notice where the pads have swept a light film of corrosion, this disc is cracked to the edge and another crack from this is clearly seen extending well beyond the 4 to 5mm length which I felt was acceptable ...
993rsr said:
I had this on a 993rs out of interest put the disc on a surface grinder the crack did not penetrate the rotor it was only on the surface .
Brittleness on heat affected zone.
The S-shaped grooves on Alcons tend to withstand better than the OEM holes. I reckon a bigger radius on the holes would’ve helped too.
Always check crack with an ultraviolet crack testing system. Rocol make a two pack aerosol set for this purpose. Sometimes the machining /grinding hides the cracks from the naked eye. It’s called a Dye Pen test. We carry it out in our workshop on metal Components that are strength critical
Edited by Redarress on Friday 21st April 23:06
That shouldn't do another track day but it's safe to drive. I cracked a disc almost from edge to edge and drove my m3 home from spa many many years ago. Couldn't believe how strong it was. I wouldn't do it now, but being young, dumb and skint I had no choice.
Thanks for the feedback on that ...
I once made a mercy dash from Spa with a friend to pick up a new pair of front discs and pads for his Z06 ...
After a fast session he had parked up in his garage but when he needed to move the car slightly found that it jammed as-if the handbrake had sprung on ... one of the front discs had broken completely, split so that the whole disc was dislocated by a couple of mm, the raised edge jamming on the brake pad material ...
A very lucky escape, and thanks to a kind GT3 Cup car owner and his techies the Z06 was fettled before the circuit was locked up for the night.
But imagine what could have happened on circuit ??? Maybe not ...
This is a source reference. Confirm exact model applicability in the original material.
