Alcons - how do you know when they need replacing?
Discussion
Hi guys,
Simple question really, has anyone got a picture of what alcons on a 996 GT3 look like when they need replacing. Mine haven't given me any trouble yet but I think the pads need to be changed soon and am I right in thinking that when you replace the discs you then need new pads on too, so if I put new pads on and then the discs wear out shortly after would I then need new pads again?
I am looking to use RS29s for the fronts as I do mainly track days with this car and I was also wondering if people run RS29s front and rear? Or different pads on the rear?
Cheers
Dave
Simple question really, has anyone got a picture of what alcons on a 996 GT3 look like when they need replacing. Mine haven't given me any trouble yet but I think the pads need to be changed soon and am I right in thinking that when you replace the discs you then need new pads on too, so if I put new pads on and then the discs wear out shortly after would I then need new pads again?
I am looking to use RS29s for the fronts as I do mainly track days with this car and I was also wondering if people run RS29s front and rear? Or different pads on the rear?
Cheers
Dave
how deep is the lip on the disc edge, does your finger catch on the lip or slide relatively easy off it or are there cracks in the centre of disc turning into crevasse then time to change.
its ideal to change both pads and disc together but by no means necessary, really depends how far the pads have gone. The new disc will not like the old pad for a while, and an area on the disc may well not be touching the pad initially, at this point gentle breaking will be needed to stop the pad digging into just a part of the disc and ruining them, but after couple hundred miles the pads will start to settle onto the new disc evenly.
If in doubt, and wallet can handle it change both for optimum retardation, and bed the new discs in correctly.
RS 29 front and rear, industry standard, superb pad.
its ideal to change both pads and disc together but by no means necessary, really depends how far the pads have gone. The new disc will not like the old pad for a while, and an area on the disc may well not be touching the pad initially, at this point gentle breaking will be needed to stop the pad digging into just a part of the disc and ruining them, but after couple hundred miles the pads will start to settle onto the new disc evenly.
If in doubt, and wallet can handle it change both for optimum retardation, and bed the new discs in correctly.
RS 29 front and rear, industry standard, superb pad.
Alcon said:
Inspection - Brake pads and discs should be examined regularly for wear and condition. Pads with less than 2mm of friction material anywhere over the friction surface must be replaced. If a disc shows any signs of cracking, which may occur when the brakes have been subjected to heavy usage, it must be replaced. Furthermore, discs must be replaced when either the total thickness has reduced to the minimum indicated on the external mounting face, or when any of the grooves across either inner or outer face have been worn away. Remember to bed in new pads or discs according to the procedure in the Installation Instructions.
Ran Alcons for several years, they really didn't wear out as such, sure there were surface cracks but these are not really an issue, the material is very tough. What did happen though is the disc wore uneven across the face making bedding new pads in more difficult and longer. Anyway suggest you replace both discs and pads at the same time as its so much easier bedding in. If the Alcons are not juddering and mine never did, and bedding in the new pads wil not be such a pain put another set in and see how they perform.
Hope this helps
Hope this helps
RS14 on the rear for better bias. RS29 on the front.
Email alcon and ask what they say ref minimum thickness for the discs and go with this.
Bear in mind pads heat cycle out so can be needing replaced long before they are at minimum. Also be wary of running the pads too low. You will start sticking extra heat into the caliper and fluid. All this is ofcourse for track.
Email alcon and ask what they say ref minimum thickness for the discs and go with this.
Bear in mind pads heat cycle out so can be needing replaced long before they are at minimum. Also be wary of running the pads too low. You will start sticking extra heat into the caliper and fluid. All this is ofcourse for track.
Edited by fioran0 on Monday 24th October 02:54
Harris_I said:
This is not true. The below pic shows an Alcon disc with surface cracking, but is perfectly safe for a good many track days and/or sprint races. JZM can confirm this.
That picture is very useful, thanks for posting. And thanks for all the other tips guys. Mine have cracks like in the pic wheres as the discs on my GT2 have none but it does not see track action. As I mentioned, the car is braking fine although I thought I felt a bit where the pedal felt odd at my last session at cadwell. So I am checking pads etc and thought I had best check the discs too. Not sure how many track days I should expect to get out of the alcons?Dave
When the discs are cold, try running your finger across the face, this will show you how much radial unevenness there is, it is this that will make the new pads hard to bed in. In the old days we would simply take them off and skim them on a lathe. Mine had similar surface cracks and were fine. If the cracks have gone deeper they will start to judder and pulse though the wheel.
The hardest area to check is the inside of the disk surface but you can get to it with the wheel off.
The hardest area to check is the inside of the disk surface but you can get to it with the wheel off.
They went on a few months after getting the car, so 5 or 6 years ago i guess. The fronts i think were still OK but i think 911V changed them for appearances purposes, they were still very effective and i would have put in at least another set of RS29s before scrapping them. Alcons really are made of the toughest steel going - i think they are amazing value. OEM disks are so inferior by comparison.
mike58 said:
As your pic shows, the spec of the disc is detailed. Why is it not possible to buy this spec of disc from any other source other than JZM? Its just a disc.Or am I mistaken here.
Mike
As I understand it, JZM have a sole agency agreement for this particular disc/application. I'm sure Jon E from Alcon will be able to confirm one way or t'other.Mike
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