School me on HP2 brakes (please)

[S2central.net]

I don't think the 2-pad version is a HP2 caliper, propably just a normal design floating caliper..? There is at least two different types of HP2's with 4-pads, as have came up in this thread. The pads are different between these two versions, so not switchable.

I suspect that is correct... I have a vague memory that I once sourced the Audi SSP for the HP2 callipers - I will seek that out and report back here if I can find it.

[UrS4boy]

My hp2 s are different to the photos above. No springs
My calipers have 2 inner pads which are held in the pistons. The outer pads are held in by 2 torxs. I will at my brakes this week so will take some photos. There is also a difference on the carrier part if 314mm discs to 323mm. The mounting holes are in a different position.

I finally got my winter wheels and tires off the V8 S4 avant today and reinstalled the Boleros. That was the first "big" (heavy lifting) thing I've done on my cars since my heart surgery. I wanted to do it to test my strength and also check the condition of the pads and rotors front and back. Both need ends need work. Front just needs pads (and soon). Rear (which is the same as my 93 AAN UrS4 sedan) needs pads and rotors (but not in a panic). I have a couple of questions for the Craing and/or the S2forum:

1. What size is that Torx that holds the pads to the HP2 calipers? (I have them)

2. Did you ever take photos Craig? If so, did you post them and I missed them?

3. 314 x30 Rotors are not available in NAmerica. Could I get A8 323 x 30 rotors and get 4.5 mm milled off their edges to create 314 x 30 rotors?

[Kieron20V]

Dave, check my thread, I stripped my front callipers and rebuilt them. Some pics on my thread.

http://www.s2forum.com/forum/showthread.php?p=892245

And on.

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[Thuppu]

Those 323mm discs woud be ok to machine down to 314mm, but you would propably be able to order right discs from ebay.co.uk or ebay.de or maybe from your local autoparts store if you go with second hand parts, Zimmermann for example.

[UrS4boy]

Dave, check my thread, I stripped my front callipers and rebuilt them. Some pics on my thread. http://www.s2forum.com/forum/showthread.php?p=892245 And on.

Thanks for the link. Interesting but it didn't answer my question.

[Kieron20V]

One of them was did you take photos? Sorry chum.

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[UrS4boy]

One of them was did you take photos? Sorry chum.

The photo question was for Craig. (K7ERG)

[UrS4boy]

Those 323mm discs woud be ok to machine down to 314mm, but you would propably be able to order right discs from ebay.co.uk or ebay.de or maybe from your local autoparts store if you go with second hand parts, Zimmermann for example.

Sorry but there are no Audis that came to NAmerica with the 441615301AA 314 x 30 front rotor, not even an early A8 (which used a 312 x 25 rotor here, and later the 323 x 30 rotor). By 2000 the A8Qs here had the 4D0615301J 323 x 30 5/112 rotor with similar critical dimensions to the "euro" 314 x 30 rotor (other than 323 vs 314). I can buy 323s for $87 each. A 314 x 30 rotor on eBay is between GBP 125 and GBP 140 ($202) each before shipping, making the 323 x 30 attractive in terms of both accessibility and price. Ignore the drilling in the second diagram.

[igor136]

This is my, urs6 1996, not like s4 b5

[UrS4boy]

I can buy 323 x30x for $87 each. A 314 x 30 rotor on eBay is between GBP 125 and GBP 140 ($202) each before shipping, making the 323 x 30 attractive in terms of both accessibility and price. Ignore the drilling in the second diagram.

Just came back from checking out a shop that can literally chuck a new 323 x 30 rotor into a metal lathe and turn it down to 314 x 30. $10 a piece. No brainer.

[A1QSHIP]

Just came back from checking out a shop that can literally chuck a new 323 x 30 rotor into a metal lathe and turn it down to 314 x 30. $10 a piece. No brainer.

Be careful that the smaller diameter of the rotor face is sufficient for the brake pad to cover. You do not want the lower edge of the brake pad to overhang the swept pad area.

[UrS4boy]

Be careful that the smaller diameter of the rotor face is sufficient for the brake pad to cover. You do not want the lower edge of the brake pad to overhang the swept pad area.

At the inner edge? I don't have any diagrams (yet) comparing the two rotors on that detail. Good point.

[UrS4boy]

At the inner edge? I don't have any diagrams (yet) comparing the two rotors on that detail. Good point.

Found these. Not just 314 vs 323, also 184 vs 193. Dayum

[A1QSHIP]

Probably not interested but may be time to do a 17z upgrade? Or maybe NeuS4 calipers & rotors?

[igor136]

Dave,
did you see the difference between URS6 brakes and S4 B5?