11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHWarped discs
Leading reported evidence
Check suspension and declared
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed
The guy who did the work checked the suspension and declared that there was no issue likely to cause vibration.
Leading evidence: 'Check suspension and declared' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check calipers and those mounting screws' (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.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
Hi, I've fitted new standard discs and Brembo Sport pads to my C2, along with Goodridge stainless braided lines.
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed
They have been fine ever since but I still try and carry out this procedure once or twice when I use the car.
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 · Original poster
I'll check the calipers and those mounting screws.
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.
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.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
2 acknowledgements have no verified action link; they do not establish a repair result.
Hi, I've fitted new standard discs and Brembo Sport pads to my C2, along with Goodridge stainless braided lines. On the road they are fine, but I've done two track days, ( Castle Combe and Spa !), and each time I've had severe vibration through the pedal when the brakes get hot. After a period of cooling, they are great again, so I'm assuming the discs are warping when hot. Any suggestions on replacement performance discs, or whatever, to cure this ?
Cheers !
You might also want to have a look at the calipers; maybe they need an overhaul for a sticking piston or something. In my experience once a disc warps, it stays warped. And vibration can also be caused by pad deposits and hot spots... :dont know:
Thanks for all your helpful replies.
Only the original cooling ducts are there.
By the second track day I'd done a couple of thousand miles at least.
I'll check the calipers and those mounting screws.
Thanks again for your help.
Yep thats what Ive experienced i.e. once warped then they still like that so it does sound like pad deposits. As above get the gt3 ducts and try again. Then change pads and see if that helps.
Warped discs?
The subject of warped brake discs continues to divide opinion.
In the attached YouTube video, it's stated that it's impossible to warp discs as the extreme temperature needed is not generated during braking - not sure if that includes track days, mind.
https://youtu.be/LVRVe1cEBDI
There have been posts on 911UK and PCGB from 993 owners - me included - asking for solutions to vibrations under braking.
Sources suggested included wear in the suspension, distorted tyres etc and...warped discs.
I had new discs and pads fitted after the calliper plates were freed off and all was fine for a while but then the vibration appeared.
The guy who did the work checked the suspension and declared that there was no issue likely to cause vibration. The disc run-out was within spec; no problem with tyres, etc.
Fundamentally, he could find no reason why the brakes should vibrate.
Then in 2019 this post and the YouTube link appeared on PCGB:
If the car is not being used much and is a garage queen it might be down to the rotors corroding (especially the inner surface). You are sort of always in a race between wearing the rotors down through use (which keeps the rust at bay) and them rusting. Also regardless of garage queen or not uneven transfer of friction material onto the rotors can cause vibration. My car can have periods of inactivity (mostly over the winter months) and I do sometimes get the vibration issue starting. I typically first notice it under light braking. When I do get it I know the brakes need some abuse to cure the problem. I will take the car out for a run when there is very little traffic about (6am works around here) and there is a stretch of dual carriage between two roundabouts I go back and forth on. Routine is accelerate up to 70MPH (because you want to remain legal right), gear into neutral (not strictly required) then hard (not violent) constant braking down to 30MPH (hence wanting no traffic following you as it scares the cr*p out of them). It is important you are braking all the way down to 30MPH or 20MPH in one go each time as it is a constant application of the brakes all the way down that gets the heat into the process.
Short 70MPH to 50MPH braking does not have
the same effect.
Repeat a number of times. Gets the disks hot and cleans it all up and transfers a nice even layer friction onto to rotors. This cures the problem for me.
PS I have standard Porsche brake pads on my 993. Never found the need for anything else on a road car.
I tried this and it worked. They have been fine ever since but I still try and carry out this procedure once or twice when I use the car. I seem to recall reading more than once during my Porsche ownership that 'we' don't use our brakes hard enough in normal driving. I've also been told this by the mechanic who services the car.
I'm not saying that this is necessarily the answer to the OP's problem but thought I would share both the video and write-up in case others are experiencing similar problems during normal driving.
27 January.
I should also have mentioned that during the time I was searching for a solution to the vibration I had the discs skimmed. As with the new discs it worked fine at first but then reverted to vibrating, just in case anyone was thinking of skimming their discs as a possible fix.
Try the method above first would be my advice.
