Hi guys,

I've recebtly had the Godspeed 335mm kit fitted to my RB5 and have been treating the brakes very gently whilst they're run in. Although I've had them on the car for about 3 weeks now, I've only been using the car to commute to/from work (all motorway) so they've only covered about 300 miles.

Over the past week or two I noticed a vibration starting as soon as I applied the brakes. Like I say, I've been braking very lightly just applying gentle pressure and leaving plenty of room to brake - no hard last minute stops or standing with my foot on the pedal at traffic lights, junctions, etc. (been using the handbrake).

Anyway, I noticed the vibration even at relatively slow speeds (30-40mph), but it gets a lot worse as speed increases. Tonight I was coming home and had to brake a bit harsher than normal when someone pulled out in front of me; no emergency stops, but they just cut my braking distance more than was necessary. I was doing about 80mph and the vibration was so bad I though the steering wheel would shake out my hands.

When I got off the motorway, I had a fast drive along some B-roads, to see if the vibration was bad with some continuous use. Jezus, it was shocking. It felt like the wheels were coming loose it was so bad.

When I first noticed the vibration I though it may just be the grooved discs since I've always had plain ones on my car.

I don't think the discs have warped as I've not used them heavy enough. I gave my OEM discs some serious abuse and never bothered cooling them down and I was guilty of resting with my foot on the brake pedal after some serious driving.

Having paid a bit more for some good discs and pads, I've been very concious that I take good care of them.

I'm going to take some video footage later just to show you how bad it is and I'll pop into my local garage (who fitted them) to ask for some advice.

Any suggestions?

Stefan

 

Which pads are you using?, as I got some vibrations through my steering wheel, when I had to make an emergency stop shortly after fitting EBC greens to my God Speed kit. Have you got any marks on the discs as on mine there are blackish spots that are apparently uneven pad deposits. Ian has emailed me to say that given a few miles of careful use they should clean up.

 

I'm running Ferodo DS2500's. I had a look tonight and there's no marks on the discs at all.

I'm off out too take some footage and you'll see just how big the vibration is. The steering wheel moves 2-4 inches

Stefan

 

Stefan,
I too have the 335 kit, although I bought it secondhand from a guy who had only done about 500mls on it, I went up to the Japfest last week, and gave them some serious abuse!!! I was getting a serious vibration under HEAVY braking, but after a few laps it went, I put it down to the pads bedding in a bit more, cos it was fine all the way home, also had a blast that evening, and it was fine.
Give it a bit of use, the pads might just be settling in, after-all, light use means they don't really do an awful lot!
Ron.

 

Ozzy , Go out and give them a good hard braking from high speeds and see if it changes , if not I'll send you another pair , Cheers Ian

 

OK, will do Ian. I'll let you know how I get on.

Stefan

 

Ozzy i too have had the same problem, i am also using ds2500 pads
I've spoke to ian and i am waiting on a new pair of discs.

Cheers,

Jason.

 

Hi lads,

Gave them a good thrashing last night. I did a couple of big stops 90mph+ with about 10mins driving in between to let them cool down.

Was out this morning and the vibration is gone at low speed, but at anything above 60mph, it starts as soon as you touch the brake pedal. I mean even gently braking from 60-55-50 over a good 300/400 meters causes far too much vibration.

Funnily enough, I did another big stop from 100mph (private road, of course) and the vibration starts off bad then you don't feel it as much/at all when the ABS kicks in and there's some tyre screach. Unfortunately, as soon as you start using them lightly the vibration comes back.

I'm assuming there should be no vibration under any sorts of load? do the grooves in the discs cause any excess vibration. I can only compare them to the OEM kit that was on before and I never had any vibration even when the pads were down to bare metal although they did make a hell of a racket

Stefan

[Edited by ozzy - 5/25/2003 4:45:32 PM]

 

The grooves should cause no vibration at-all. only maybe a slight 'drone' when used hard, sounds like you may have warped them somehow, or, maybe there's a bit of muck on the hub face behind the bell, hence the discs would be 'square' to the caliper, either way, it needs sorting!

 

Sounds to me like you've got some run out on a disc or discs.This can be caused bya little rust/dirt getting between the mating surfaces of the hub/new bell of the replacement kit. I've had this once in many changes of discs on cars over the years...it used to be quite easy to tell on older "direct" braking systems as the brake pedal would pulsate under your foot...and the steering wheel shake like hell...and usually when you get it,the more brake pressure you apply,the more the symptoms appear. The problem is that once it starts you tend to warp the discs,and even though you may be able to skim them in an attempt at getting rid of the warp,your better off starting with a new set of discs/pads.

 

Thanks for the info. The vibration is still there and it's just as bad. Tried another blast coming home tonight and it was frightening at times.

There's a single-track tarmac'd road about 7-miles long that I know very well. The hedges are all very low, so you can make sure nothing is coming before giving it some stick.

There was a couple of times at 70mph+ where I'd start braking and the car would get pulled to the left or right. At one point I'd have been off into a ditch if I never lifted off the brake pedal.

After Ian recommended giving the brakes some hard use, I've a 3 or 4 hard drives over the last couple of weeks. The vibration is annoying enough and I'm worried it's not damaging anything else like the wheel bearings, but I've got to wrestle the car to keep it straight when on the brakes

I'll need to speak to Ian tomorrow to see how I can sort things out.

Stefan

 

Are these two-piece discs? If so, they are quite hard to warp.

When fitted, was the hub cleaned of rust? If not, suspect not running perfectly true.

If the answer to the two previous questions is yes, then I would would guess at pad deposits. I also run DS2500 pads and sometimes get vibrabtion, which I've not experienced with other pads. Suspect DS2500 are more prone to this. The solution is to give them some serious grief - like 100-10mph at least half a dozen times with the brakes banging off the ABS. Never allow the car to stop until the brakes are cold again (a few minutes driving).

If it's pad deposits, they're not there now But Ian will sort you out.

Richard.

 

Hi Richard,

Yeah they are 2-piece. I've gave them several big stops as suggested, but still no luck. The discs look clean, so I don't suspect deposits. I never fitted the discs myself, so can't comment if the hubs was cleaned. I would guess so knowing the garage that did the work.

Ian is sending me some replacements, so I'll get all this checked when they fit them. Hopefully we can find out what was wrong.

I'll keep everyone updated.

Stefan

 

Make sure the hub faces are totally free of any buildup. I use a wire brush attachment on an electric drill, then finish with emery paper to ensure a flat surface.

The other odd bit you mentioned was the pulling to the left and right..

Bit odd.
Is it still the original Subaru 4 pot calipers or have they been changed as well? Could be sticking pistons on 1 side of the caliper(s)

Alan

 

Ozzy,
Re the pulling, not the same standard of brakes but on my Wifes Skoda Octavia that was shaking the wheel slightly & had a tendancy to pull to one side or the other under braking. It proved to be warped discs & they were replaced under warranty.
One other thought, when you fit the new discs spin the hubs & check they are running true before you put the wheels on. there are gadgets for measuring this. On the Hi-spec (or low spec depends on your views) I think they give tolerances. presumably Ian could also give you figures

[Edited by Stuart J - 05/06/2003 08:53:26]

 

I've got same problem too - 335mm kit - running mintex.

Please let us know how it gets resolved.

Cheers,

Chris

 

Hi,

Yes, it's still the original 4-pots. The car never pulled left/right before the brakes were fitted. They were stripped, cleaned and bled when the new disks were fitted.

Ian said that the system may need re-bled as warped discs wouldn't cause the car to pull left or right.

The car doesn't pull all of the time and as it only happened 2 or 3 times it may just have been tramlining badly. I don't recall it doing this on the same road before, but it's pretty narrow and unless I hit the same braking spot I can't tell.

I'll try this evening on a nice flat wide peice of tarmac. If it brakes nice and straight, then I guess it was just excessive tramling on that particular road (and I'll be more carefull braking into the two corners ).

If I have time, I'll take the wheels/discs off and have a good look at the faces. I'll take some pics for everyone to see for themselves and offer and more suggestions.

Thanks for everyone's help/advice,

Stefan

 

Be careful with warped discs and your steering rack or the vibration will kill that too.

I think Hoppys advice is sound and I've had a similar, if milder experience of this DS2500 thing. Generally you may feel the grooves through the pedal but shouldn't through the steering wheel. Your judder seems a little too extreme for the normal build up of deposits under normal gentle driving.

Try reading the Stoptech white papers.

F

 

Ian,

RE email 19/05/03. Can you let me know when i will be receiving the replacements for my warped discs

Thanx

Paul

 

Hi folks,

You thought I'd let everyone know I've just received my replacement discs & bells from Ian. Hopefully I can get the swapped over this weekend and have an answer to my problems.

Stefan

 

Hi all, I've collected some info on Brake Judder
All about brake judder
Regards, Jan-egbert

[Edited by TTZZ - 6/26/2003 12:33:26 PM]

[Edited by TTZZ - 6/26/2003 8:15:23 PM]

 

Looks like you've been doing a fair bit of looking round

One point - for a road setup, isn't M1166 a bit over the top? - we used to say it was for single seater / track use and is way too harsh for the highway... (unless you want it for track use etc - you'd never get the stuff warm enough to get the best out of it in "normal" driving )

BTW DTV can occur for the reasons as you've found and is quite often noticed on motorway journeys when slowing down on an exit sliproad - the discs have "wobbled" / worn uneven on the long journey without any brake applications and then the judder starts on the first application, i.e. slowing down on sliproad which may be gentle at first rather than emergency / hard breaking.

Apple

 

The standard brembo galfer pads were a real piece of ****, no friction and tremendous wear.
The pagid rs4-2 (bleu) and the mintex m1166 were comparable.
Even with cold brakes they had more friction then the galfers on all circumstances. The wear was als far more better dan the galfers.
The only problem with these pads, they are more harsh for your disc's.
More hot particles on the wheels and doors, they burn in into the paintwork.
Regards Jan-egbert
Pad survey

 

Hi folks,

Just to let everyone know that the vibration was due to the coating being steadily (and unevenly) worn off the discs. I had to wait a few weeks for replacement discs (Ian's a busy man) and in that time the vibration steadily reduced until now where it's non-existent.

The more serious problem of the car pulling violently was down to some air in the nearside front caliper. This unbalanced the system, causing the offside caliper to bite more and pull the car towards the ditches A simple (and proper) bleeding of the two brake systems sorted this.

Just like to thank Ian for taking the time to send me replacement discs and bells (that I thankfully didn't need) and to the rest of the guys input in this post.

Cheers,
Stefan

 

What coating? Youre not saying that the rotors were fitted without removing the protective grease/oil first are you?

 

No our discs are zinc plated , the plating wears off where the pads sit but the rest of the discs stay coated and stops them going rusty

 

Hi

Had this problem with mintex - upgraded to 1155 which work perfectly other than squealing (this is bad in town - sounds like a lorry stopping).

I also had deposits on the rotor surface which I sanded off by hand and cleaned the disk with brake cleaner.

No more deposits with 1155 as they can withstand higher heat and have metallic bits in the pad that also keep disc clean.

The cold braking is the same as with 1144.

Cheers
Paul

 

Ozzy,

Offside and ditches AND a smiley!!! WTF! Guess it keeps you 'lert though... Hope you meant nearside though as I winced so hard I nearly gave myself a headache reading your last post/reply.

Vindaloo.

 

Ian,

would you say best advice is to give the disk surface a rub with emery cloth before fitting then to help break through the coating?

 

No , just drive easy for the first few miles and it will come off , thats all weve been doing for the last 13 years or so with no problems , I think Ozzys gave him problems as they wernt bled properly so was giving uneven braking and not cleaning the discs off evenly.