Brice

I've changed my brake pads (Hawks HPS),changed fluid ,drived 500 miles one month ago... and then gone to the dijon prenoix track (France), ex formula 1 track) ... first track time for me and my corvette, lots of fun !

(here is a video clip [[/url])

well now I feel the brake pedal, very soft ... I can still see the abs warning when hard braking
but ... i don't know ...I'm not yet in confidence with brakes...maybe just a feeling... But I'm sure the care didn't stop as before

Do you have some ideas? I've checked the pads, nothing wrong (visually), a lot-lot-lot of brake dust in the rims after the track

outnumbered

Did you use Dot 4? And what brand of DOT 4?

I just used Hawks HP plus for the first time this past weekend. The ABS went absolutely crazy. However that was when I left Traction control on.

When I ran in Competitive mode it was much better.

I was very happy with the Hawks.
Dan.

Brice

fluid : AP Racing DOT 3 ! not dot 4 !
No problem before the track, perfect braking

gkmccready

Did you bleed the brakes before _and_ after the track day?

Brice

no bleed after the track day!
is it required ? the brake level didn't change

Brice

no bleed after the track day!
is it required ? coud be this be my problem?

02impactblue

you may have boiled the fluid in the calipers. Try bleeding the brakes and see if your pedal returns to normal. I would recommend dot4 for track use.

Brice

okay ! I'll try tomorrow morning ! thanx

outnumbered

Try Motul 600 or Casterol SRF.

We use Motul 600 with no problems.

gonzalezfj

Any time your brake pedal is not hard, your first move should be to bleed the brakes. I am 99% sure bleeding will cure your problem.

As matter of standard procedure, you should bleed your brakes before and after every track event.

I am not familiar with the AP fluid you are using. I use AP 600, a good DOT 4 fluid that I recommend highly.

Enjoy your car.

Z11409

Also insulate the metal brake lines below the resevoir and the resevoir itself.Remove the hood seal at rear of hood to help the hot air buid up escape from within the engine compartment.

John Shiels

could be pad taper also you may not see the taper unless they are in your hand.

AU N EGL

After a hard track weekend it is time to do your brakes again. Rember you just driven very hard and you really can not expect your brakes to still be good?

Hawk HPS is a STREET pad not a race or track pad. DOT 3 is too low for track use, and a DOT 4, Motul 600 AP 600 or ATE super Blue ( Gold) or Castrol SRF

Brake pads for the track, Wilwood H, Hawk DTC70 front and DTC60 Rear, PFC-01 or 03s, Carbotech XP12 front and XP10 rear.

Bill Dearborn

More than likely pad taper. A very common problem on C5 brakes during an HPDE. Brake pedal travel will be very long for several weeks until the taper wears down some. Here is a picture of the taper I saw everytime I got a long pedal at an HPDE (every one of them).



No amount of bleeding would get rid of the long pedal but a pad change to non tapered pads would fix it right away. These pads were taken from the right front caliper and you can see how the rotation (counterclockwise) of the caliper as the brakes are applied causes the taper.

Bill

rick g

I took my C-6 for the first time and am also feeling a soft brake pedal. You think the same applies for the C-6. How long to feel normal or should I just buy new pads?

Sidney004

I measure the inside throat dimensions of the caliper with a set of prescision "calipers" and monitor them after every event. You can measure the permanent set that takes place. All of these PBR style calipers are prone to spreading when you clamp down on them and the calipers are at elevated temps. New pads will temporarily solve the problem but you will junk a $200 set of pads in no time. In most cases, the cost effective solution to pad tapering is a new(or used street driven) caliper. By the way, the AP 551 looks like good fluid if it is fresh
http://www.apracing.com/car/brakeflu...sp?code=CP7551
(as with many others I use Motul 600) and I would recommend speedbleeders so that you could routinely and quickly bleed your brakes prior to the event as well as at the track in a pinch if you need to. As an aside, AP Racing also had an interesting section on pads, although most are European:
http://www.apracing.com/car/brakepad/performance.htm

rudyarias

Main reason I went with the Stainless Steel Brake Corp Tri Power floating caliper. Have not had that porblem since then.

freefall

I get the same - when I swap my street pads back in, the pedal's nice and firm.

Bill Dearborn

One thing I should make clear. I differentiate between a long pedal and a soft pedal. For me a long pedal is increased travel before hitting a solid point. The solid point feels the same as before the pedal travel increased except it is closer to the floor. On my cars the pedal travel increased to the point I could no longer heel and toe downshift because my foot couldn't reach the gas pedal due to the brake pedal being so low. Usually a double pump would bring the pedal up to the correct level. When I was using stock C5 brake pads with my 97 I would install a new set of pads shortly before a two day event. The picture I posted is one set of those pads after two days at the track. If I left the pads in the calipers and used the car on the street the pedal would start to come up after several weeks of driving.

In my parlance with a soft pedal you do not neccesarily hit a hard point when you apply the brakes. This is caused by air in the brake system and since air is compressible the feel is more like hitting a cushion. Pedal travel will increase with this type of problem but you almost never get a solid feeling brake pedal even after pumping it.

I doubt the taper shown in the picture is due to caliper spread as it is in the wrong direction for that type of taper. If you look at the picture as showing the pads mounted in the right front caliper you can see the caliper rotated slightly on its guide pins when the brake was applied which put more pressure on the upper outboard pad and the lower inboard pad (one with the wear indicator located in the trailing position).

Bill

Brice

So I have a long pedal...too much work yesterday, to time to bleed my brakes. I go to norway this week end.
Here is my homework for the next week :
-bleed it
-Check the pads
-and wait several weeks