Wrong Size Rotors - 2004 S80 T6 Topic is solved

Post by **SuperHerman** » 21 Jul 2018, 22:13

Best approach is to take the wheel off - look at the various caliper part numbers (if Volvo rotors they should have part numbers) and POST PICTURES of the current state of affairs, the caliper bracket, caliper and rotor.

With this information no more guessing.

Post by **Rattnalle** » 22 Jul 2018, 00:28

jimmy57 wrote: 21 Jul 2018, 16:53 I ran the VIN in current live VIDA. Nice car with 4C. The build brakes were 16 inch set. I don't think p2 S80 in US ever got 17 inch brakes.

The 15 and 16 brakes use the same pad and caliper but the bracket for caliper is different. It moves the caliper outward few mm to get pad placement to edge of rotor. If 286 mm 15 inch brake set rotors were installed on the car the pads would off the edge of rotor and some of the braking face of rotor would not be covered by the pads. The 19 mm differnce between the 305 mm and 286 mm rotors would change pad location about 10 mm.

Rim size doesn't determine rotor size. Engine does. You could still order larger rims.

Yendor72 · Post by **Yendor72** » 22 Jul 2018, 11:32

Thanks a ton!! I have enough info to get the right thing now. Just need to confirm on the car then I'm good.

Post by **Rattnalle** » 22 Jul 2018, 11:38

Measure how far off the pad is. Take the rotor off and measure it. Add the difference and you'll almost certainly end up buying 16" rotors

Post by **mrbrian200** » 22 Jul 2018, 11:43

jimmy57 wrote: 21 Jul 2018, 16:53 The 15 and 16 brakes use the same pad and caliper but the bracket for caliper is different. It moves the caliper outward few mm to get pad placement to edge of rotor.

I spaced that... A 305mm rotor can't be installed on a 286mm setup without changing the brackets, the caliper would interfere. Seeing as the tech appears to be throwing a tantrum, more than likely a PO installed 286mm rotors on the 305mm OE setup.

You should be able to see this through the wheel without taking it off: the pads would be overhanging a little bit (probably ~1/4 inch) off the outer edge of the rotor.

Talk about mid-life crisis/messed up priorities PO... $ on larger wheels for looks but didn't care about much else (improper size rotors installed, probably in a 'pinch', not corrected ASAP). Not necessarily middle aged...mid life crisis starts at age 15 for some people and never ends.

Yes, this needs to be rectified with the correct size rotors. Yes, this would likely impact braking performance significantly. Yes the installer/shop should insist: simply replacing the pads while leaving the undersized rotors creates a liability issue.

Post by **Rattnalle** » 22 Jul 2018, 12:08

The rotors are even almost the same price regardless of size.. Really strange to put the wrong ones on there and leave it as it is.

Post by **oragex** » 22 Jul 2018, 13:48

Slightly off topic, but are the brake discs the same on the S80 non turbo (2.

with some of the S60 models?

Post by **Rattnalle** » 22 Jul 2018, 13:55

oragex wrote: 22 Jul 2018, 13:48 Slightly off topic, but are the brake discs the same on the S80 non turbo (2. with some of the S60 models?

All P2s share all brake parts afaik. The NA I5s have 15“ discs, turbos 16“. Swedish police cars 16,5“. Unsure about the 2.8.

quietlymknnoise67 · Post by **quietlymknnoise67** » 22 Jul 2018, 16:41

I have a 2006 S80 with 17" wheels and the rotors are 286mm. I had to measure the rotors to be sure of size.

Post by **oragex** » 22 Jul 2018, 17:47

Appreciate!