mbb993

Looking for some advice to decide what to do with my brakes.

Sebring last weekend having a blast and during a long session (for me) of about 35-40 minutes brakes started to fade, felt pedal getting lower so slowed down for a lap and came into the pit for a rest. This was all so very exciting! After five minutes no brakes and pedal goes to the floor until pumped a few times but only recovered completely after 10 minutes or so. Brake fluid reservoir full no obvious leaks.

First time for this experience for me. We were going into the the last run for the weekend was tired anyway so decided to play it safe and call it a day and head home.

Today I am doing a bleed and remove the pads, checking things out and have a few questions for the group. Is there anything specifically I need to check?

Plans for the car will be 95+% track for DE's only at this point.

Here's the current situation:
1. Stock black calipers and rotors. Fronts rotors soon to be replaced are now right at min. spec of 30mm, although they have no significant cracks. I have a pair on order. Rears are still good.

2. Hawk HP Plus pads all around (choice of and installed by my mechanic ~5months ago.) Now with 11mm remaining on the fronts, more on rears.

3. Brakes last bled with ATE Gold after last DE [Ihowever[/I] except for a few miles around town the car was sitting for the past 3 months.

I guess there is still some time left on these pads, but I am thinking it might be a good time to replace both front rotors and change brake pads to something more approprate for the track. After searching here it looks like I should consider either Hawk HT-10's or Pagid Yellow's.

Also, should I stay with same pads front to back? Considering changing ATE to Motul 600?

Any advice will be greatly appreciated.

Thanks in advance.

Bull

The Hawk HP-Plus pads are best left to the street driving. I like the Hawk HT-10 pads for both performance and price. i used them with my 993 for 5 years, along with ATE Blue fluid and a bleed before every event, and never had any fade. This was doing 30-35 days a year in the Red run group.

If the car will be sitting for several months, bleed the brakes before an event. Motul will also help.

Steve Weiner-Rennsport Systems

Hi Mark:

If you are going to use stock 993 calipers and rotors when participating in DE events, I would recommend SRF brake fluid without a doubt. Nothing else comes close and you really need the best under those circumstances.

Personally, I'd be using Pagid pads in lieu of Hawks for better heat management; RS-19's (yellow) are OK for your application.

TR6

How about Pagid Oranges? How do they compare to Yellows? I'm running Oranges right now for DE.

bobt993

Agree with Bull, if you stay with Hawk pads (which I use for club racing), you need a more aggressive compound. I have not run Pagids and that may be good advice. You also want to consider RS airducts via the fog lamps up front. This is an easy add-on and really helps with front brake cooling. If you remove the backing plates leave the area next to the ABS sensors in tact ( I found this out the hard way). The sensor can go bad from the added heat.

ltc

^+1.
SRF, there is no substitute.

mbb993

So far sounds like the consensus is to ditch the Hawk HP-Plus pads.

Hi Steve, I was afraid SRF would come up! $$$$

Bobt993, by the "backing plates" are you referring to the heat shield behind the rotors? I already have the brake ducts in the bumper but have had no time to run the hose to the brakes and doubt they are doing much anything without them.

I found that some of the "spiders" were still in place and removed them today. Should I leave them out? These brakes were squealing quite nicely with them in! One of the spiders disks was missing but I found the metal clip still inside the caliper piston so I extracted that.

Steve Weiner-Rennsport Systems

Greg:

Oranges are just fine; they are a bit more aggressive than Yellows (which are their endurance pads).


Mark:

Yup,.....the SRF is certainly not inexpensive but thats what we use for cars such as yours that have good deal of power, are not light, and have slightly undersized brakes for track usage.....

Bull

I would stay away from the Pagid Orange pads given my experience with my 993s and the experience of many friends both at DEs and in Club Racing. We found that the old Pagid Orange technology doesn't work well with the heavy cars and really hot brakes. They will leave deposits on your rotors, which will build up to the point that the car will shake very badly under braking. Many have spent money on new rotors before discovering this problem. The high end of the heat range that the Orange pads are built to operate within is not high enough for today's heavy cars. If you want to spend the money that Pagid demands, use either the Pagid Black or Yellow pads. Hawk HT-10s will give you the same higher heat range, last as long and cost significantly less.

BTW, if you end up with the Pagid Orange rotor deposits shaking your eyeballs when braking, just install some aggressive track pads of another brand and it usually cleans that up.

GUMBALL

When you are running hard and the brake pedal gets soft, the one thing that you DO NOT do, is come into the pits and stop. All that does is allow the brake system to heat soak, completely boiling the fliud.

My suggestion, would be to do several slower laps, keeping OFF the brake pedal...allowing the brakes to cool. Then come into the pit.
Once the brake system has cooled, then bleed your brakes - once the fluid in the calipers has overheated, it must be flushed (this usually only takes 2 - 3 pumps per caliper)

ZAPmobile

Hi Steve, I was afraid SRF would come up! $$$$

Try and get some more air to the brakes, that will help. I use AP 600 brake fluid and should be cheaper, and just as good or better. You must completely flush all the old fluid out.

mhm993

Steve, you mentioned heat management a couple notes above. may I slightly hijack this thread and ask a related 993 brake pad question? I used PF 97's for several years. but found that they were not entirely rotor friendly but they stop crazy well. This year I used several sets of Porterfield r4's which are not only rotor friendly but also moderately priced compared to many brands. Today, I noticed that the outer O rings on many of the pistons are really chewed up and a couple calipers even smelled kind of acrid--and since I had donor parts, just swapped calipers. . My question, related to your answer above: Is this likely a function of age and use or does it indicate I have a heat dissipation problem with the Portfields? (FYI, I bleed every couple events and never have soft pedal problems. Black brakes. Car has about 65K miles. Car is driven hard)

Flying Finn

I once tried those Hawk + pads at Moroso and all it took was one day & about 100 track miles and the brand new pads were done (metal against metal) so not so much for the heating issues but for longevity, get Performance Friction (97 compound) or Pagids and then start thinking about cooling those brakes.

Brake fluid as already said makes a difernece but I never cured my brake over heat problems before i installed cooling ducts to my front brakes. And I usually brake pretty hard & for a short time which for brake temps is a good thing. I also have stock 993 brakes.

If better fluid & pads won't help, check www.p-car.com for brake duct cooling DIY.

mdrums

I boiled my ATE Blue brand new brake fluid during my last DE at Sebring. I switched to Motul 600 and did not have a problem at the next DE. I also am running Pagid Yellow RS29 pads on stock rotors in my 997S. I have only done 1 DE on those so far and they are working for the street too. The rear brake howl a little on light stops and in stop and go traffic but the car will out brake the tires no problem!

still researching and searchng for suitable track wheels and tires I can drive to from the track in.

bobt993

Yes, and you need the hoses to the brake calipers, otherwise the ducts are just for show. They can be mounted to put aire directly on the backside of the caliper. Make a cut out on the heat shield to accept the hose and hold it in place. Hawk HP plus is a good street pad. I have had no problems with the DTC60/70 and HT10 compounds.

Remove the squeel springs as they get in the way when performing a quick pad change.