PDA

View Full Version : Upgrading from 11" to 12" front rotors



javaxc70
08-10-2011, 11:28 AM
I have just picked up a set of 12" rotors for my 01, does anyone know the caliper bracket required to make this work? I am doing a brake swap out, and want to do a little upgrade for my new DD. I have reached a wall in my searches... Thanks! :)

billr99
08-10-2011, 11:49 AM
I have just picked up a set of 12" rotors for my 01, does anyone know the caliper bracket required to make this work? I am doing a brake swap out, and want to do a little upgrade for my new DD. I have reached a wall in my searches... Thanks! :)

According to VIDA, the bracket (titled a "retainer") available for 15in wheels (obviously 11in discs) is PN 8251318. For 16in wheels its PN 8251316. In the 2010 version of VIDA, all references to the two brake options are listed as those for the 15in wheel and 16in wheel. I would suggest you double-check, these numbers before you lay down your money, just to be safe.

BTW, I did this mod on my 850R and although it was an improvement, it was not huge. On that car, it also shifted the brake balance a bit more to the front which actually went a way that I preferred. I'd be interested to hear your feedback after the mod to see how much an improvement you get.

Cheers,

Bill

javaxc70
08-13-2011, 07:46 AM
Bill,

Thanks for the reply, i will search and see if i cant find those for a reasonable price. So far the cheapest place for caliper retainer has been around 16 a piece. I will keep all posted once i order the part and receive it. Thanks!

billr99
08-13-2011, 03:43 PM
Bill,

Thanks for the reply, i will search and see if i cant find those for a reasonable price. So far the cheapest place for caliper retainer has been around 16 a piece. I will keep all posted once i order the part and receive it. Thanks!

$16. That's probably about right, give or take. I got mine from FCP Groton, but it is an item that you have to e-mail or call to get a price. If you do that mention this site and I believe they'll give you a 10-15% discount. Also as I recall when you get the brackets you also get the associated hardware like the pins, boots, etc. so at $16 a side, it's pretty reasonable considering all that you get. But check to verify as I got mine a few years ago.

Cheers,

Bill

javaxc70
08-16-2011, 03:39 PM
I just wanted to report back that this simple brake upgrade works!

Here are the steps required to do this:

1) Pick up a 12" rotor from any reputable source that fits your model year; in my case a 12" rotor for 2001.
2) Purchase the bracket for 12" rotors; I got mine from rock auto under caliper bracket. The part number on mine was A-1 Cardone 141607 and was labeled ATE 503. Price was $16 per bracket and about $40 shipped.
3) No need to replace brake pads, caliper, or other parts. Simply swap out the caliper bracket and rotor and you now have upgraded "budget" performance brakes!

There is less brake pedal required to stop under heavy braking.

All and all I consider this to be a great "budget" upgrade! [thumbup][thumbup]

ocean 506
07-05-2014, 08:28 PM
Caliper brackets are no longer available aftermarket as far as I can tell. I ordered mine through Tasca Volvo along with the rotors. Here are a couple of photos to show size difference.
629862976296

Antherzoll
07-28-2014, 09:28 AM
Just got mine in today, can't wait to install them!
6360

Antherzoll
07-28-2014, 12:21 PM
6361636263636364

violinista03
11-19-2015, 12:33 AM
6361636263636364

What is the part number for those stoptech rotors? It's on the side of the box on your photos above.

Antherzoll
11-19-2015, 08:21 AM
What is the part number for those stoptech rotors? It's on the side of the box on your photos above.

http://www.eurosporttuning.com/volvo/brakes/brake-rotors-front/powerslot-pair-305mm-s60-v70-xc70-s80.html

Antherzoll
11-19-2015, 09:37 AM
I'll post this up here from my "build thread"


If anyone is interested, here is the accumulated brake dust on my front drivers side wheel after this trip.

http://i1376.photobucket.com/albums/ah2/antherzoll/Mobile%20Uploads/IMG_20150622_121647_zpspfgyylr3.jpg (http://s1376.photobucket.com/user/antherzoll/media/Mobile%20Uploads/IMG_20150622_121647_zpspfgyylr3.jpg.html)

Using Hawk HPS Semi-metallic pads on 12" Slotted Stop Tech rotors. Didn't wash my vehicle once on the whole trip and rain was quite minimal. I did use engine braking in the big hills, which may have reduced the amount of dust. The brakes performed well on downhills and a few hard stops with the additional load. A bit noisy when wet, but dissipated once hot, otherwise they are very quiet.

That's after a +10k KM trip hauling around a 2000lbs trailer.

Antherzoll
11-19-2015, 10:36 AM
Slots don't really do much for me, it's not like we're tracking it.

Neither do I. I purchased slotted rotors because I'm usually driving the XC loaded to the max through hills/mountains.

Astro14
11-19-2015, 12:01 PM
I have slotted rotors on the T5.

The slots allow for a faster bite in the rain. Small difference, but the rotors grab very quickly, instead of a split second hesitation in heavy rain that comes from wiping the water film off the rotor.

The downside is a bit more noise under heavy braking...kind of a resonant hum that comes from the slots, I reckon.

saltycyclist
11-19-2015, 03:42 PM
Just ordered those rotors from rockauto, Thanks for the head up on them! What pads should I get? Ive heard on here Antherzoll going with Hawk, and nsjames going with Akebono. I'm geussing they have good bite and low dust?

Astro14
11-19-2015, 03:54 PM
I have Akebono Euro Ceramics on both Volvos and Both Mercedes. Love 'em. super quiet. Zero dust. I've heard complaints that they have less initial "bite" when cold than other pads. I've not noticed any degradation in braking. I really recommend them.

Antherzoll
11-20-2015, 02:37 PM
No steering stops on the XC control arms. Steering stops are at the rack behind the inner tie rod.

They are going to fit.

Iroll_
11-23-2015, 04:41 PM
I have just picked up a set of 12" rotors for my 01, does anyone know the caliper bracket required to make this work? I am doing a brake swap out, and want to do a little upgrade for my new DD. I have reached a wall in my searches... Thanks! :)

Hope this helps-

As Javaxc70 said

" Default Upgrade Successful!
I just wanted to report back that this simple brake upgrade works!

Here are the steps required to do this:

1) Pick up a 12" rotor from any reputable source that fits your model year; in my case a 12" rotor for 2001.
2) Purchase the bracket for 12" rotors; I got mine from rock auto under caliper bracket. The part number on mine was A-1 Cardone 141607 and was labeled ATE 503. Price was $16 per bracket and about $40 shipped.
3) No need to replace brake pads, caliper, or other parts. Simply swap out the caliper bracket and rotor and you now have upgraded "budget" performance brakes!

There is less brake pedal required to stop under heavy braking.

All and all I consider this to be a great "budget" upgrade!"

IVIUSTANG
11-23-2015, 05:12 PM
Hope this helps-

As Javaxc70 said

" Default Upgrade Successful!
I just wanted to report back that this simple brake upgrade works!

Here are the steps required to do this:

1) Pick up a 12" rotor from any reputable source that fits your model year; in my case a 12" rotor for 2001.
2) Purchase the bracket for 12" rotors; I got mine from rock auto under caliper bracket. The part number on mine was A-1 Cardone 141607 and was labeled ATE 503. Price was $16 per bracket and about $40 shipped.
3) No need to replace brake pads, caliper, or other parts. Simply swap out the caliper bracket and rotor and you now have upgraded "budget" performance brakes!

There is less brake pedal required to stop under heavy braking.

All and all I consider this to be a great "budget" upgrade!"

I concur, I also have done this on my XC and it works flawless; even with inside wheel weights.... barely fits, but fits :)

Jesse

Astro14
11-24-2015, 05:17 PM
Take a cell phone photo of your caliper before disassembly. Ensure that the spring is correctly placed when you put it back or your pedal will be very low...

Ask me how I know...

JRL
11-27-2015, 09:09 AM
Better pads and SS brake lines would have accomplished the same thing

Antherzoll
11-27-2015, 04:34 PM
Better pads and SS brake lines would have accomplished the same thing

Good pads, possibly. SS lines, I'm highly skeptical. OK so there is less expansion with SS lines, but how much of a decrease are we talking about? The rubber hoses will not expand infinitely, they will stretch to a point and that's it, which may be beneficial for pedal modulation in light to moderate braking. Initial pedal feel may be improved with SS lines, but overall braking performance will not IMO.

Here's the best article I've come across:

http://www.autospeed.com/cms/article.html?&title=Braided-Brake-Lines&A=2679

Note that these tests were conducted with the brake hoses pressurised to 3500 psi, which is considerably more than you’ll generate in a car – David says you might generate 1500 psi pressure in a hard brake application. This means the hoses will expand more in our tests than in a real-world application.

So how did the hoses compare?

Well, the first hose we tested was an old and worn rubber hose (which appears to be the original part from a ’65 Ford Mustang). In static conditions, this hose had an OD of 10.76mm and, when pressurised, it expanded to 11.02mm. An increase of 2.4 percent.

Next, we tested a brand new rubber hose. The new hose had a 10.47mm OD which expanded to 10.65mm when pressurised. An increase of 1.7 percent.

The final test was a new braided steel brake line. In static conditions, the braided line had an OD of 6.45mm and expanded to 6.49mm when pressurised. An increase of less than 1 percent. So what can we conclude from this?

Well, yes, a braided steel brake line does give less expansion under pressure than a rubber hose - but the margin is extremely small. And keep in mind that these tests were conducted at more than double the pressure you might generate in a real-world situation. So the difference between braided steel and rubber brake hoses is extremely, extremely small...

howie2092
11-27-2015, 06:51 PM
I did the 12" rotor upgrade on my 1998 V70R with good results, back in the day. Very inexpensive upgrade if you are replacing pads/rotors anyway.

RockAuto has the Cardone 141607 caliper brackets for $15.15 each and just 3 of the closeout Brembo rotors left for $15.35 each. Mine are on the way!

Also, a quick web search will get you a 5% discount code for RockAuto.

Thanks everyone - for posting the part number and Brembo deal.

aerobaticsfan
05-22-2016, 11:47 AM
I have tried to stitch together info & am not sure. What year/size rotor am I looking for & year model caliper bracket to accommodate a larger rotor? I have a XC70 2005 & best I can tell 11.5 rotors. Is there a build sheet for the upgrade?

Astro14
05-22-2016, 02:18 PM
You don't have 11.5" rotors.

You have either 11" or 12". 280mm or 305mm. If you've got the bigger ones, then you need nothing.

If you've got the smaller ones, then you need brackets, rotors and pads.

Take off a front wheel and measure accurately.

XC generally came with 11". T5 came with 12". But build sheets are meaningless since the 12" rotors will fit under a 16" wheel and lots of owners upgraded the brakes. I've bought the brackets to do this on my wife's XC this summer when I replace the front brakes.

billr99
05-23-2016, 05:13 AM
You don't have 11.5" rotors.

You have either 11" or 12". 280mm or 305mm. If you've got the bigger ones, then you need nothing.

If you've got the smaller ones, then you need brackets, rotors and pads.

Take off a front wheel and measure accurately.

XC generally came with 11". T5 came with 12". But build sheets are meaningless since the 12" rotors will fit under a 16" wheel and lots of owners upgraded the brakes. I've bought the brackets to do this on my wife's XC this summer when I replace the front brakes.

Just to further clarify, calipers and pads are the same for both the 280 and 305 options. Basically, the braking advantage of the 305 over the 280 is that by moving the same pad further out away from the centre of the rotor, swept area is increased. Obviously, you will not get any increased in actual pad area and braking feel/effect (given all else being equal) of the 305 over the 280 is minimal at best. I've done this mod on 3 out of the 4 white block cars I've had and frankly, it is more for looks than anything.

Cheers,

Bill

Astro14
05-23-2016, 06:37 AM
All true Bill.

The reason I said new pads and rotors is that I would never put old pads on new rotors.

And now that the brackets are only $15 on Rock Auto, I will do the upgrade because I'm buying rotors anyway...

billr99
05-23-2016, 10:01 AM
All true Bill.

The reason I said new pads and rotors is that I would never put old pads on new rotors.

And now that the brackets are only $15 on Rock Auto, I will do the upgrade because I'm buying rotors anyway...
Yes, absolutely agree. However, I have used both used rotors and pads that were close to new on their wear specs with the only requirement being a use of coarse sandpaper to break the glaze. But yes, old, close to worn out bits should never be used.

Cheers,

Bill

aerobaticsfan
05-23-2016, 12:51 PM
Roger that , I have the T5. I used a best effort to measure & it failed , I will remove rotor for 100% accuracy before an order. My Mother has an 06 XC90 14xx miles away , I order rotor kit for her to have installed & there were 2 sizes offered & I was sent the smaller size, it took the 332mm ish the larger of the 2. I am running into this now on my XC70 , the form says "with 15" wheels" I have not yet seen a 15" equipped XC70. Well if I could add a condition, I found a local set of OEM 04 XC90 set of 18" wheels....5 spoke chrome too. I just might get them.

sanfelice
05-25-2016, 08:27 AM
Just to further clarify, calipers and pads are the same for both the 280 and 305 options. Basically, the braking advantage of the 305 over the 280 is that by moving the same pad further out away from the centre of the rotor, swept area is increased. Obviously, you will not get any increased in actual pad area and braking feel/effect (given all else being equal) of the 305 over the 280 is minimal at best. I've done this mod on 3 out of the 4 white block cars I've had and frankly, it is more for looks than anything.

Cheers,

Bill


Exactly. Never really understood this mod, as it also adds unsprung weight to the front end.

Astro14
05-25-2016, 07:55 PM
Exactly. Never really understood this mod, as it also adds unsprung weight to the front end.

Why, then did Volvo fit larger brakes to the faster model T5?

Seriously...if they offer only more weight, then why bother?

The answer is that those same pads, in the same calipers, moved out 25 mm have greater swept area (friction area), greater leverage on the axle itself (a roughly 8% increase) and the rotor has greater resistance to heat. Now, 8% may not be a ton of leverage improvement, but there is a braking performance advantage to the larger rotors.

sanfelice
05-26-2016, 12:48 PM
Why, then did Volvo fit larger brakes to the faster model T5?

Seriously...if they offer only more weight, then why bother?

The answer is that those same pads, in the same calipers, moved out 25 mm have greater swept area (friction area), greater leverage on the axle itself (a roughly 8% increase) and the rotor has greater resistance to heat. Now, 8% may not be a ton of leverage improvement, but there is a braking performance advantage to the larger rotors.

the "greater swept area" is untrue - area is area if the contact patch is the same. the leverage may be somewhat beneficial, but I would wager a goodly sum that no one would be able to tell the difference, as bill so succinctly states. and, yes, you are adding unsprung weight. again, a negligible amount, but something.

switch to metallic pads and save yourself the expense, time and effort.

now, switching calipers to the R brakes would be a big improvement. anyone done that on an XC with success?

BillAileo
05-26-2016, 04:07 PM
While the contact area of the pads remains the same, the rotor circumference area that that pad material ends up being pressed being pressed against is larger per each revolution assuming that if the rotor has a larger diameter the position of the pads is at a correspondingly further "out" distance from the center of the rotor.

Astro14
05-26-2016, 04:36 PM
Swept area is as Bill describes: the annulus on the rotor that is contacted by the pads. It is a metric in determining brake system performance.

Therefore, because the pad size is the same, swept area cannot be the same between 11" and 12" rotors, so San Felice is wrong.

sanfelice
05-26-2016, 08:41 PM
While the contact area of the pads remains the same, the rotor circumference area that that pad material ends up being pressed being pressed against is larger per each revolution assuming that if the rotor has a larger diameter the position of the pads is at a correspondingly further "out" distance from the center of the rotor.

I see what you are saying. Yet, a larger rotating mass (rotor) would probably negate any advantage to stopping the car any quicker, I would imagine. The heat dissipation angle is interesting, but, again, I imagine it to be negligible in real world driving.

Astro14
05-26-2016, 10:01 PM
I see what you are saying. Yet, a larger rotating mass (rotor) would probably negate any advantage to stopping the car any quicker, I would imagine. The heat dissipation angle is interesting, but, again, I imagine it to be negligible in real world driving.

I see...so bigger brakes don't add any stopping advantage? Because they add rotational inertia? And don't offer any advantage in leverage even though the moment arm is longer with a bigger rotor?

So, that's why high dollar performance cars fit the smallest brakes possible, because they reduce unsprung weight...right?

Hmmm....OK...whatever you say...You've clearly done the math...

I mean, you never see a Porsche, or Mercedes, or any other performance car with big rotors, because those big rotors "negate any stopping advantage"...

billr99
05-27-2016, 07:06 AM
And finally, to dust off everyone's high school geometry:

1) Measure the distance from centre of the disc to the outer reach of the pads. That is r1
2) Measure the distance from centre of the disc to the inner reach of the pads. That is r2

Total Brake Swept Area = ((3.1416 x r1^2) - (3.1416 x r2^2)) * 2

That is, the area of a circle is Pi times the radius squared. So basically you calculate the total area of the disc and then subtract the area of the circle defined by that of the disc not contacting the pad. Then you multiple that value by two for total swept area. That is, both sides of the disc.

So as you can see, if the radius of the disc increases (and assuming the pad area remains constant) then you will increase swept area. Interestingly using multi-pot calipers with larger pads may not increase swept area if the inner and outer reaches of the pad are the same as a smaller pad. It is here then that larger pad area comes into play as an increase in friction area (a factor in the co-effecient of friction?) rather than a consideration of swept area. And why F1 cars have very small discs but pad area that wraps around the wear area of the disc almost to the full circumference of the disc (and not getting into the effects of energy recovery and braking as is current in the hybrid F1 setups).

Wow, was wondering when I'd use some of that math I learned in Grade 10 (and some 46 years later).

Cheers,

Bill

sanfelice
05-27-2016, 11:04 AM
I see...so bigger brakes don't add any stopping advantage? Because they add rotational inertia? And don't offer any advantage in leverage even though the moment arm is longer with a bigger rotor?

So, that's why high dollar performance cars fit the smallest brakes possible, because they reduce unsprung weight...right?

Hmmm....OK...whatever you say...You've clearly done the math...

I mean, you never see a Porsche, or Mercedes, or any other performance car with big rotors, because those big rotors "negate any stopping advantage"...

Have you been following along? The discussion concerns a static pad size, regardless of the size of the rotor.

sanfelice
05-27-2016, 11:12 AM
Billr, yes, my F1 fan friend was illustrating this same fact. He pontificated about the weights of the front end suspension and g forces.

Astro14
05-27-2016, 04:09 PM
Have you been following along? The discussion concerns a static pad size, regardless of the size of the rotor.

I've been following. Same pad, same force. The larger rotor places the pad farther the out from the axis of rotation.

So, the same friction force from the same pad acts with roughly 8% greater torque when the rotor size (and therefor "m" in the formula T=mxf where T is torque, m is the moment arm and f is the force) is increased from 280 to 305 mm ( which would increase m from 140 to 152.5 in the case of our Volvo)

This is basic physics. I assumed that you knew something of that. Clearly, I was in error...

Let's follow your logic for a moment: you should cut a few inches off every wrench you own, since there is no advantage to a longer wrench, only added weight. Think how much weight you could save in your tool box! After all, the longer moment arm of the longer wrench gives you no advantage in developing torque...

Let me know if you're getting this.

Because once you see the logic here, then we can discuss how swept area affects braking performance and heat. If this is too much for you, I'll just stop...and wish you happiness in your beliefs.

UCrazyKid
08-31-2017, 07:34 AM
I'm so glad that I found this thread. I just completed the 11" to 12" (280mm to 305mm) rotor conversion with my last brake change. I picked up some high carbon Pagid rotors, Akebono pads and the caliper brackets at RockAuto. The conversion was just the same as changing rotors and I couldn't be more happy with the results. Better braking characteristics and I think an even better braking bias (front/rear). Thanks!

Astro14
08-31-2017, 12:44 PM
I did the same on our XC. The 12" rotors with calipers just clear the 16" wheels.

Better brake feel. Modest improvement in performance. Well worth the $30 in brackets if you're already buying rotors and pads. A great mod.

verdeo
09-04-2017, 09:24 PM
Just acquired a 2005 xc 70. Does this upgrade apply for it, as I think I already have the 12" rotors stock. Don't want to order unnecessary brackets. Thanks

billr99
09-05-2017, 02:20 AM
Just acquired a 2005 xc 70. Does this upgrade apply for it, as I think I already have the 12" rotors stock. Don't want to order unnecessary backs. Thanks

Yes, it applies but check what you have first. My used '05 came with the smaller rotors which I upgraded as soon as I bought it; but from what I understand, the larger rotors can be more common in some markets.

Cheers,

Bill

verdeo
09-05-2017, 02:50 PM
Thanks, Bill

I pulled a wheel and found that I have the 11" rotors. I've ordered a couple of brackets from Rock Auto and pads/rotors from eEuroparts...nice labor day discount from them. Glad I discovered this nice forum!
Gary

verdeo
09-14-2017, 08:52 AM
Well, I've upgraded my front and rear brakes on my "new to me" xc70. It was a learning experience on how to utilize common tools in a creative manner. Ex., the rear hex bolts, one anyway, left little clearance from the rear spring. I dug around and found a 7mm right angle wrench that helped significantly!

What is perplexing to me now...the pedal is still going down a long way. I've read a number of posts on various forums suggesting various brake bleeding options. I never had issues bleeding brakes the old pre-ABS days but have had issues a couple of times with newer cars with ABS. So, I am wary of jumping in with this car, as others have stated I may need a Volvo programmer to activate the ABS module to remove any air trapped there.

I just ordered a motive bleeder as one option so I'm covered for a back up for manual bleeding. Do I need to have a programmer too? If so, any suggestions on one that will adequately solve issues with this particular model?


update: just read through the other thread involving soft pedal and springs on incorrectly. I've checked all of that twice, so am going to proceed with the Motive bleeder next..then go from there.

Thanks in advance!
Gary

Astro14
09-14-2017, 12:01 PM
You may have checked the spring - but get a known, good picture and check again.

I've got $20 that says your springs are on wrong!

verdeo
09-14-2017, 12:07 PM
Thanks Astro, but I've checked several times with good pictures. When I began this brake service the original brakes had the issue. I thought doing a brake job would resolve everything, but pedal feel remains the same after new pads and calipers were installed. Only wish it were that simple!

billr99
09-14-2017, 12:32 PM
Thanks Astro, but I've checked several times with good pictures. When I began this brake service the original brakes had the issue. I thought doing a brake job would resolve everything, but pedal feel remains the same after new pads and calipers were installed. Only wish it were that simple!

Keep in mind that Volvos have always had what I consider to be a soft pedal when compared to things like VW, MB, BMW or Porsche. When I compare my R to my XC (or my '96 R for that matter that had 12" rotors and SS lines), pedal feel is pretty similar although the R has a wee bit better actual performance. So don't confuse what might be normal for a problem. Make sure you check your braking system thoroughly; then if you can't find anything, chalk it up to Volvo's soft pedal.

Cheers,

Bill

verdeo
09-14-2017, 04:55 PM
Well, Bill. Thanks for your description. My Motive came this afternoon and I put it to use immediately. Bled them using the compressed air method without adding fluid to the jug. It worked just fine and I did get a few bubbles out of the first caliper. After that it was hard to see any more bubbles. I tightened everything up and went for a spn.

They were somewhat better and the further I went they became very secure so I'm happy with the overall effort of replacing everything. Your description really helps me to feel comfortable with them now. They are much different in comparison to my Jaguars..just touch them and they are cranking! Even the V60 is pretty hot compared to these.

So, thanks to everyone on this forum for providing such good information for those of us that are not familiar with these great cars!