normal brake rotor temperatures?

[seaner]

Hey folks.. I've noticed my 08 RR is starting to shudder a little at moderate speed - thought it may have been the road, but I suspect otherwise. Almost feels like it's missing, but nothing on the dash lighting up.
On the way home today I noticed a brake squeal with the window down.. only caught it once, but it prompted me to check my brakes.
I just finished a ~10 mile drive home down back roads (ie. only half a dozen stops) and pulled out the thermometer to check the rotor temps.
front 2 were @ 45C (113F), the rear 2 were 101C (213F) and 170C (338F!!!).
I'm guessing I should take those rear brakes apart real soon!

Can anyone else check their rotor temperatures after a short jaunt? I'm guessing 44C is fine. I am guessing 101 and 170C are not fine. That one rear hub may be burning through its grease I imagine.

 

[seaner]

on the trip into the office today, one of the rear rotors got to 212C (414F)! I should start baking back there.

 

[seaner]

281C at one point on one of them tonight (538F). definitely building a pizza oven.

 

[az_max]

Are they glowing orange or anything? I've never measured the temp of the rotors, but I don't think they get that hot.

 

[Nomar]

I would go for a short drive, a few miles.
Use the brakes as little as possible and the last mile or two just coast to stop somewhere without ANY brakes.
Record the temps again.
Likely a sticking caliper.


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[kk88rrc]

I would go for a short drive, a few miles.
Use the brakes as little as possible and the last mile or two just coast to stop somewhere without ANY brakes.
Record the temps again.
Likely a sticking caliper.


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Why waste the time. I know nothing about the new RR's but that sounds like a seized caliper. Park it until you can tear into it.

280ºC is too hot for a pizza oven! I do my pizza around 240ºC.

 

[seaner]

Why waste the time. I know nothing about the new RR's but that sounds like a seized caliper. Park it until you can tear into it.
280ºC is too hot for a pizza oven! I do my pizza around 240ºC.

hehe.. indeed. definitely sounds like the situation. pins are supposed to arrive friday. wonder how long it has been like this. grr

 

[Nomar]

Why waste the time. I know nothing about the new RR's but that sounds like a seized caliper. Park it until you can tear into it.

280ºC is too hot for a pizza oven! I do my pizza around 240ºC.

Now there's an idea...could you wire-tie the pizza on to the hot wheel and drive just slow enough to cook the pizza but not too fast that the wind would cool it or blow all the cheese off?
I guess not...


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[seaner]

Well, the pizza idea didn't work
Pulled the brakes this weekend and the guide pins were fine. looks like the caliper/piston are seized though. Couldn't for the life of me get the cylinder free, so just put it back on. Coasted to the end of my road (500m) and the brakes got up to 500F. Taking my foot off the gas, you can really tell it's not coasting. So at least that mystery is solved.
Will just take it into the shop Monday and have them swap out the caliper(s). I'd do it myself, but would also like them to tell me what's up with the shudder I'm feeling lately when driving - possibly brake related, or perhaps one of the hubs is going. when I had the brakes off, if I spun the hub by hand, I could hear a bit of a grating/grinding sound. Thought it might be the parking brake brushing against the inside of the rotor, so brushed all the crap out of it (seems like a pretty poor design there). oh well...

 

[seaner]

I can now confirm that the normal brake rotor temperature on an 08 RR is about 35 degrees C after driving about 2km with 3 or 4 stops in there. Not 305 degrees C.
Ended up swapping in new rear calipers. Pistons in at least one of the old ones was seized - couldn't get it out to rebuild, so back they go for my CORE refund.