AdamS2K00

Hi All

A bit of advise required.
Have only had my S2000 about 2 months and last week installed new discs and pads all round, along with a brake fluid change.
They are drilled / grooved discs and EBC Yellow Stuff Pads, with ATE Superblue fluid.

Having been bedding the brakes in a little before a trackday later in the month, the car is pulling violently to the right when braking hard from higher speeds.
I obviously don't want this on the track as the car will be all over the place!

Next job I need to do is get the alignment checked, but does anybody know the exact factory settings / can send a link to these? (I have tried searching around but there are so many opinions / options)

Has anybody had a similar experience, and would this sound like an alignment issue?

Many Thanks
Adam

richmc

All the setting are in the tech FAQ, so you haven't been searching very thoroughly.

And sounds like a sticky caliper or crap disc issue.

"I obviously don't want this on the track as the car will be all over the place!" more like heading into the right side Armco.

AdamS2K00

Just what I was after, still finding my way round the forum!

Nick Graves

Pulling violently to the right all of a sudden suggests you've got air stuck in the left front circuit; it can be a bugger to get out if it's in the ABS module.

Presuming your calipers are not partially-seized, search for brake bleeding, gravity bleeding, etc..

AdamS2K00

Thanks for that.

My mechanic did bleed the system, but could well be it.
Calipers were all free and didn't pull before getting bled.

markforrester99

It could be a caliper issue i guess.

How much have you actually bedded in the brakes thou? Brakes will always pull when first installed as both pads wont have the same swept area until they wear to match the brake disc. When i change my road pads back to my carbotechs i have to work them really hard to get the braking even and square.

It will be interesting to see how you get on with the yellow stuff as every trackday i have been to the yellow stuff pads have been slated. In my experience they are rubbish on the S2000 but i guess it depends abit on the circuit and the braking forces. A few of my personal experiences at Snetterton

- yellow stuff fadded after about 2-3 laps and when i came into the pits the rears were pretty much on fire
- My friend in his scooby fitted them and they went from brand new to worn out to the backing pad in the space of the day

Nick Graves

Reading too quickly Mark - he wrote new discs & pads & it didn't pull until he buggered it all up be trying to bleed the brakes.

That's usually what happens...

markforrester99

Admittedly new discs and pads should provide a perfect area for the pads to bite equally side to side but you have things like wheel bearing run out etc. which can still make it pull to one side abit until its all bedded in. Thats why people always moaned about warped discs when half the time its the lack of the hub face being cleaned up with a wire brush causing the runout rather than the disc itself.

I would be tempted to take the car out in the dry and give the brakes a real beating with lots of hard stops getting near to or engaging the ABS. This has to be done safely thou ie when there is no traffic and on a straight bit of road. If it still pulls after that then i would be tempted to take everything apart again and check that everything was put back together properly. If there was alot of air in the brake system you would feel it in the pedal. The travel would be awful and spongy. There would be no harm in using the two man method to bleed it just to be sure.

Andy_F

Few things I would do in this situation. Exercise the pistons in and out a few times all round, ensure the system is bled properly (its quite hard to do well on S2k's). Also look up Bilman's fluid bleed method - this worked really well for me. It's basically the process of disconnecting the battery and wedging the brake pedal all the way down overnight. This pressurises the system and forces air back out the path of least resistance - the master cylinder. You'll be amazed at the increase in pedal feel. Also definitely get the alignment looked at, particularly as you're going out on track anyway. Don't go to a normal tyre place, go somewhere which specialises in alignment, ideally a Hunter rig. Anywhere decent will be able to bring up the stock settings from their system, you can then request tweaks from there if you desire.

When I did an all round pad/fluid/braided line change I ended up with some pulling to the left because I accidently ended up having to take the LH piston all the way out. This made it much more free than the RHS, making my LH more efficient until I got some proper temps into them on track - this would be my guess as to what is happening in your system. One of your pistons is probably a bit stiffer than the other, meaning the fluid will push the more free piston onto the pad first, giving you more braking on that side initially. If you press your brake pedal really hard, I would expect your car to brake in a straight line again.

Also, I've used Yellow's on a few cars. I found them perfectly good on the S2k, but they didn't last more than one and a half track days - I am very hard on my brakes though. Just keep an eye on your levels of wear. I never had any fade through the course of ~20 minute sessions - they just wore at a high rate when very hot.

GreenmanS2000

Have the tyres worn evenly? When was the geo last checked? Mine had similar symptoms after new discs, pads and callipers until I had the geo reset (& new tyres)