Brake questions

[DavidM]

I've got some dumb (and maybe some even not so dumb) rookie racer brake questions. My front brake rotors are pretty grooved. I understand that racing pads are very abrasive, but when should you get new rotors? When does it become too grooved? I haven't experienced any issues with the brakes, but I'd rather replace them before that occurs.

Lets assume that I did get new rotors. Seems like I would want new pads as well. The old pads are going to have the same groove pattern as the old rotors and it seems like these would just regroove the new rotors fairly quickly. Am I thinking correctly here or can I use the old pads and they will just wear flat on the new rotors?

If I have new rotors and new pads how do I bed them? I've read a couple places that you want to bed new pads with old rotors and new rotors with old pads. I may not want to use the old parts for fear of grooving the new parts. So what do I do? Also, I've seen "pre-bedded" pads. Do you really not need to bed these or is this just a marketing gimmick?

Finally, the bedding process itself. Most of the stuff I've seen has you getting up to speed and then rapidly slowing down to get heat into the brakes. You increase your speed after a few runs up to some top speed. For race pads it seems you start off around 50 or so and work up to 80 or 90. Where the hell do you do this? The only place to me seems like the track, but it also seems dangerous to me to be slowing down to 10 or 20 on a racing course even during practice days. So do you just do it off line or is there some other way?

This is on an ITA 1989 240SX if that makes any difference.

Thanks for your replies.

David

[ITA240]

David,
Use the Hawk HT-10's for the front, unless you have upgraded to the legal ABS sized brakes. Hawk doesn't make the ht-10's in this pad, so you can use the blues instead. Follow the directions inside Hawks bax, and the pads will last longer.

Any grooves that result in a thickness which is less than the minimum spec for that rotor is too much. I don't remember the spec for the 240's rotors though. Some may think I wasted some good rotors, but they are cheaper than the brake pads, so when I even began to question them, I got new ones.

Jim

[joeg]

I'm with Jim.

I change rotors frequently (never turn them) and keep using the pads. Mine are a lot cheaper than race pads.

Bedding is a problem because of track time limitations. However, if you use Hawk Blues, they do not really need bedding. Other brands do, so if you have a practice opportunity, use it wisely.

Regards.

[zracre]

and old pads, as long as they have enough meat on them, will not groove or ruin your new rotors. Hawk blue pads are my favorite but they do destroy rotors fast. i get about 1 set of rotors per set of pads with them. If I run Cobalt, i can get 2 sets of pads per set of rotors. I agree with joeg and ita240....rotors=cheap pads=expensive...

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Evan Darling
ITA Integra

[charrbq]

Having been there and done that. Expensive brake pads are way cheaper than cheap brake pads. Having used up sets of rotors, calipers, brake lines, etc. in one weekend...several times, I finally came upon Hawk blues. In my travels, I've since discovered Panther Plus from Carbotech. Best brake pads I've ever come across! I change pads only twice a year. A new set before the 6 hour enduro in the fall and a new set about three more races into the next year. Got several pair of used pads left for spares during the year.

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Chris Harris
ITC Honda Civic

[Nigel Stu]

So here's a related question -

what happens if you do not bed in the brakes as indicated? or do not go through the full process?

or if you put new brakes on, drive the car on the street (assuming its legal to do) just to make sure all your fancy new components are OK, then bed them in at the track the following weekend?

do you loose anything by doing this?

Thanks
Ben

[Knestis]

Probably not a problem but they are not bedded in at that point. Some compounds are more sensitive to bedding procedures than others. Hawk Blues, for example, get comfortable in a practice session on my car. I just don't lean on them hard.

K

[Greg Amy]

<font face=\"Verdana, Arial\" size=\"2\">what happens if you do not bed in the brakes as indicated? or do not go through the full process?</font>

You run the risk of either A) all of the pad bonding agent suddenly trying to rush out at one time and you pad-fade or damage the pads, and/or B) you create a very hard "glaze" on the surface of the pad from this stuff crystalizing (and it don't got near da friction coefficient of the good parts of the pad). - GA

[Bill Miller]

I know that the Hawks say they're 'pre-burnished', but I always bed them during a practice session. Take it easy on them for a few laps, and then hit them hard once or twice at the end of the session. Works for both the Prod car as well as the IT car.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Nigel Stu]

Thanks guys - it sounds like I luckily have Hawk blues, and should be able to get them bedded in all right during my first practice session the day before my first race of the year!