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D4 - Axles, Brakes, Suspension and Steering Brakes, Springs, shocks, steering racks, steering columns, suspension arms, wheel hubs etc.

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  #11  
Old 25th January 2019, 04:44 PM
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Not sure if it's just cosmetic work you want on the calipers but if it's for a refurb use these

https://pro-calipers.co.uk
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Last edited by briang9; 25th January 2019 at 05:48 PM.
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  #12  
Old 12th February 2019, 08:54 AM
manca manca is offline
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Just seen today Audi Fixed Price Services have gone up. Front pads and discs up from 525 to 875. Ouch.
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  #13  
Old 16th February 2019, 05:04 PM
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Architex_mA8tey Architex_mA8tey is offline
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Quote:
Originally Posted by manca View Post
Just seen today Audi Fixed Price Services have gone up. Front pads and discs up from 525 to 875. Ouch.
Yikes well that just means even less people will use them for that now then as well, ridiculous!
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  #14  
Old 16th February 2019, 09:08 PM
manca manca is offline
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Originally Posted by Architex_mA8tey View Post
Yikes well that just means even less people will use them for that now then as well, ridiculous!
It's a huge increase as you say but still cheaper than I was quoted by the Indie guys in Harrow. I have been told there was a massive hike in parts prices which is why the fixed price has increased so much. I've also just had the sports diff throw a warning light so thats made my week.
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  #15  
Old 20th February 2019, 09:33 PM
funkmiester funkmiester is offline
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My sports diff throws a warning light now and again. Particularly after a long drive all ok (with stops), then get home for half and hour, pop to the shops and ping, then goes on. Gone by the morning. Also prone when very wet/damp which makes me think its a cable/connection rather than a genuine fault. I may get around to it in the summer and since I don't take it round the nurburgring every weekend it's not a problem.Yet.
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Last edited by funkmiester; 20th February 2019 at 09:38 PM. Reason: *Edited for clarity, too many words missing to make sense!
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  #16  
Old 20th February 2019, 09:49 PM
funkmiester funkmiester is offline
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On the subject of discs and pads though, a Quick ebay brings....
https://www.ebay.co.uk/sch/i.html?_f...discs&_sacat=0

36 pads TEXTAR is a brand I know of
https://textar.com/

86 a pair of brand new discs
The disc manufacturer has been around 50 years
https://www.apecbraking.co.uk/Company/About.aspx

Doesn't seem unreasonable. An Indy wouldn't bankrupt you fitting them.
Would OEM steel be better?Hmmm doubt it. If it fits and is balanced and flat it will probably be OK.
Would OEM Pad be better? well that is a question. Textar is the OEM supplier to Tesla so not exactly chinese knock off's, I'd give them a go.
Thoughts welcome.
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  #17  
Old 21st February 2019, 09:14 AM
MikkiJayne MikkiJayne is offline
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Quote:
Originally Posted by funkmiester View Post
Would OEM steel be better?
Yes, without a doubt. There are noticeable differences in the quality of the steel between OEM-standard discs and cheap alternatives.

OE, Brembo, Pagid are all much the same. They wear evenly and surface rust is just that and cleans off easily. For those of us with cars that don't go out much, the discs will rust due to rain and the UK climate. High quality discs will clean off quite easily and not damage the pads doing it. As the discs wear, the surface tends to stay flatter and the pads are less likely to wear grooves in to it so a set of discs can easily last for 3 or even 4 sets of pads (unless you go to Audi who change both every time).

Cheaper discs made of cheaper steel with more impurities rust much faster and that rust eats pits in to the surface. Those pits retain rust as they're not cleaned off by the pad and so they rust more easily. The rust is also coarser and so eats in to the pad surface. The pads can also wear grooves in to cheap steel more easily so the discs end up looking like the surface of a record and can also be quite noisy. Cheap discs last maybe 2 sets of pads if you're lucky, but by then they will be pretty ugly. I've also found that pad contamination due to water retention after washing is worse with cheap discs.

Brembo, Pagid, Textar, TRW, ATE are all tier 1, equivalent to OE and my go-to brands. Not only do they last longer, but most of them come with surface coatings to retain their appearance which is important on high end vehicles like ours.
A T1 disc could be left on a hibernating car outside over winter and be cleaned up to 99% with a wire wheel on a grinder. You wouldn't be able to tell.

Mintex, QH, Borg & Beck, Delphi, Febi - tier 2. Decent aftermarket. Won't last as long as tier 1, but ok. Plain steel so the hubs will rust quickly. I don't have experience of Apec but I suspect they belong here.
A T2 disc left over winter will clean up to 50%. There will be pitting on the surface and discolouration where the rust was. The pads will have left a noticeable mark on the surface. It would need to be driven for a while to shine up the surface but it won't be as smooth or effective as before. The section where the pads were will be more 'grabby' than the rest and could lead to brake wobble.

Eicher, anything from GSF, own-brand stuff you've never heard of - tier 3. Made from finest recycled Chinesium. I really wouldn't.
A T3 disc left over the winter goes in the scrap pile.

I've concentrated here on the most visible aspect of different grades of disc, but also consider that higher quality steel conducts heat more efficiently too. Given that the brake system functions by turning kinetic energy (movement) in to thermal energy (heat), the disc's ability to disperse that energy has a direct impact on how effective the braking system is. Does it matter on a diesel A4 that just goes to the shops or the school run? Probably not. On a 2-ton V8 rocket couch, I'll go for T1 every time.

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Last edited by MikkiJayne; 21st February 2019 at 09:17 AM.
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  #18  
Old 21st February 2019, 06:05 PM
funkmiester funkmiester is offline
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Thanks for that info, it's really helpful to understand your use case and experience.
My experience (regardless of the car) is the pad choice is vital but stick to OEM or your suggested Tier 1 list and you'll usually good.
Turns out (with a bit of googling) they don't really make discs out of steel, they are grey cast Iron GG-204 (unless you have the S8 ceramics!). It, like any commercial alloy has standards. I'm not saying a backstreet Chinese set won't be made from recycled bicycles but they will mostly be made of the same thing.
I don't over-winter a car and never have (unless you talk about the Lancia Beta that slowly dissolved in front of my eyes-ahem). I drive them so the long term build up you see is not a problem for me. Obviously buying a new set every time you take the car out would be be inconvenient.
I'd be very interested to see the quality of the casting and subsequent machining for any disc vs OEM. eg sharpness of the cast, number of fins, % of disc material to fin thickness etc.
If you don't over winter the car, don't do track days or daily alpine passes and the discs look OK from a manufacturing point of view I'd try them, especially if they are manufactured in the EU. What is the price of a set of D4 Audi OEM front discs and pads?
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  #19  
Old 21st February 2019, 07:56 PM
manca manca is offline
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Quote:
Originally Posted by funkmiester View Post
My sports diff throws a warning light now and again. Particularly after a long drive all ok (with stops), then get home for half and hour, pop to the shops and ping, then goes on. Gone by the morning. Also prone when very wet/damp which makes me think its a cable/connection rather than a genuine fault. I may get around to it in the summer and since I don't take it round the nurburgring every weekend it's not a problem.Yet.
That's interesting. Mine started about 8 weeksago lasted for about a fortnight and seemed to come on for alternate journeys. Then all went quiet ..... But has started again. I've been told it's likely to be the oil and temp sender's and that there is a Repair kit for them
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  #20  
Old 26th February 2019, 08:47 PM
funkmiester funkmiester is offline
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There is a very helpful detailed explanation of the sports diff fault on here. Including pictures. It's one of two sensors. Very hard to reach need a special socket. Don't change both sensors at once, anyway check the threads. For update purposes mine is on for now, sometimes...
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