guardsredcab

Hot day at VIR last month brakes stopped working. Still firm pedal but just no bite - ran off end of front straight. Pulled front pads (Pagid Orange) and they were very shiny - glazed over. Installed new Pagid Blacks and ran three more sessions without incident. Pulled those pads today and they look pretty slick too.

I know I need to get more air to the rotors. I already have the RS front bumper cover, just need to figure out how to get the air from the ducts to the brakes. Anyone have suggestions?

Main question: I now have two sets of pads with lots of material left but glazed surfaces. Is there any way to salvage the pads? Sanding, grinding, etc.? Anyone have suggestions?

Thanks
Greg

LDadrenaline

just scrub them around on the ground. concrete works fine. I do it before I put a set of pads in, regardless.

J richard

Carbide rubbing stone from home depot, in the concrete/masonry section. Makes fast work of cleaning up pads and smoothing crumbled edges. Couple of bucks, lasts forever.

guardsredcab

Thanks guys!

Carrera51

Were the Oranges new? Sounds like they were not bedded in properly since they glazed over and you had a firm pedal, but the pads were not grabbing as they should. I had this happen many years ago when I tried to bed new pads in on the way to the track one morning. Here's a link to their bedding procedure.

http://www.braketechnology.com/brakepadbedding.html

guardsredcab

Thanks Mark. The oranges were actually spares from the previous owner that I installed at my previous event. They worked fine for one day at that event, but it wasn't as hot as it was at VIR. The glazing happened on the second day at VIR. So, I'm not really sure what happened. The Pagid Blacks were not bedded in and I guess that could be a reason for them to have some glazing.

I've now putting new rotors on. Ideally, I'd start with fresh pads too, but since I've got two sets of pads with over half of the material left, I'd really like to get some use out of them. Pretty expensive parts!

Assume I should follow the bedding procedure with whichever pads I use because of the new rotors not having any material deposited on them?

Thanks again.

Carrera51

Greg:
Before you install the RS14s you have, scuff them up before installing them. I like J Richard's idea and I am going to pick up one of those stones he mentioned next trip to Lowes. When installed, follow Pagid's bedding procedure. Doing it on the street is always tough, so I would bed them the first run session of your next track event. Go out at the back of the pack, follow the bedding procedure and you'll be good to go.

Veloce Raptor

Greg, I am still thinking that at least part of the issue was caused by near-zero airflow onto the front caliper/rotor area on a track where we saw mid 90's ambients and brake zones where we were seeing 5-4-3-2 downshifting.

kurt M

In my limited experence I have seen increased airflow cure all kinds of heat related brake issues. Even adding home made scoops on the arms makes a notable change. I am runing S and M calipers on a 993 powered 911. Stock rotors 06 pads, huge air flow. Still on the first set of rotors pads last almost a season.

I heard a good hint for glazed pads and rotors. Wash the car and inside the wheels, watch the near instant flash rust form and then rebed the pads the next day. I have done the pads on concrete trick and it works well.

mark kibort

you might have just grown out of pagid oranges. im doing this to the blacks now, but its only when they get really cooked and there is only 5mm pad left. Ive heard that there are some other pads that will still work effectively at this thickness and dont get so cooked they loose stopping power at the high temp ranges. the cooling thing is valid, but if it happens early on , on lap 1-5 of a race, cooling isnt going to change it much. Im thinking the pad gets glazed as you saw at very high temps, beyond its capability or in my case, even using the blacks, they get so cooked that their friction abilities gets limite. i noticed eve on the street now, they dont even squeal, where they screamed like babies up until they got down to about 8mm. very interested to see if the PFCs will do this.

guardsredcab

OK. Got the carbide rubbing stone. Treated one set (blacks) to that and the other (orange) to the concrete. I'll try to re-bed both sets on my new rotors before the next track day at the end of this month and see what happens. I'm also going to buy another set of blacks before that event just in case.

Now for the cooling issue... I have the stock 993 "flanges" attached to the lower control arms. Even though the euro RS bumper cover has "brake ducts" there's not conduit for the air to get to the rotors. When I first acquired the cover, I was advised by RListers that it really just funneled air to the oil cooler and that was more important anyway. My oil temps were fine even at VIR. So, it seems I need to figure out how to get air from the bumper inlet to the rotors. I'll ask on the 993 forum too, but if anyone has ideas, I'd appreciate hearing them.

Thanks for all your help
Greg

Eifeler

I believe it's best to break in a new set of rotors with used pads of the same compound as the new ones you plan to run(if that's an option).

guardsredcab

it is. thanks