Right I think I've murdered my brakes. I get huge amounts of vibration under braking and it feels like the steering wheel is gonna jump from my hands.

I'm currently running a Focus ST170 conversion on the front and standard rear drums on the back (been on for 9 years). I'm seriously considering getting shot of the drums as power is at 250bhp and I wanna know it will stop when I press the middle pedal. What can I do with my ST170 conversion to improve it and is it worth fitting discs on the back. I don't mind spending a few quid (to a point) but don't want the wobble to return after 2 months of use.

 

Sounds more suspension components than the dics to me mate if its only 2 months use on the discs

 

Nowt left on that front to be replaced mate

Did find a knackered TCA when the car was pollybushed and this was replaced. It feels like somthing is out of true under braking as when braking lightly the brakes feel as though they are pulsing on and off

More fookin money

 

it could be ur rear drums. Mate had this porblem recently. We put all new suspension compmnets and discs on the front and it still happened. Swapped the drums over from mine and it was perfect. Really werid as its the steering that was vibrating.

 

Sounds like severely warped brakes. I know its only two months use, but thats my guess. Gotta find out why though

My RST had 283mm cossie discs up front and these would need replacing every 6 months 'cos they warped. Dunno why, but a lot of ppl have warping trouble with big brakes on an RST.

steve

 

Alot of people have trouble with warped discs using EBC Greenstuff pads!!
Try Ricks idea, seems feasable

 

Fooked Hubs

 

OOps think I may have not been clear enough in my initial post. What I meant was I didn't want the wobble returning after 2 months. The conversion has been on there for about 6 months. And was fine when fitted.

New hubs were fitted not too long ago as well so I should be able to rule these out.

 

Rick mate that sounds exactly like what I'm experiencing

James : I don't use EBC brakes any more due to probs in the past. Having said that though I still stand by them being really good on the XR

 

Ah right mate. Its just that i condememd my disc on my last s2 after only a few months, and it was a bush.

Rick could be right its weird how it affects the steering etc but ive known it happen b4

 

Like I said I've not changed the rear drums in the 9 years I've owned the old girl so may be time to do somthing with them

 

reckon so mate

 

Stickey calipers

 

Warped discs! the reason your steering wheel wobbles is because the Discs are like a buckled wheel and the force from the caliper pistons is causing the wheels to follow the discs warped fashion! Reason being you've been braking too hard and and getting them too hot.

Are they Drilled? As any cooling will help, alternatively brake sooner you LOON or use your gears more.

If the Pedal pulses up and down when you brake then thats a pretty good sign your drums are ovaled!

Remember Drums are better at braking than Discs but they are NOT as efficient and get too hot too easily. When was the last time you adjusted the shoes?

If your discs are getting that Hot you could do with some high boiling fluid (If you havn't already)

 

The way you drive it's not surprising that you keep killing your brakes you loon

If you haven't changed the rear drums for 9 years I'd go for a rear disc conversion as the ST170 setup on the front should be fine , I know you have just had the polybushes done on the front so if it were me I'd do the back brakes and go from there.

 

Cliff, Just cause his ST170 discs are new doesn't mean you can't warp them!

 

Very true, but when me and Steve kick around together when I am home we know quite abit about each others cars and even had a grudge match together.

 

sounds like warped discs,i wouldnt have thought the discs on a st170 would be able to put up with hard braking on a 250bhp rs for long

 

Fine on mine and I've had them on since January, I suppose though cos I have seen his driving

 

first off try finding wether its on the front or rear,to do this when driving slowly pull the hand brake up,if the wobble comes on then,well its your rear drums,if not then look to your disks,
If it is the front get a Dial Test Indicator (dti)with a magnetic base and set it up on your disk,if you have more than .003" running error i would say these were at fault,(try both sides on both disks) this is probably the cheapest and quickest way.

 

Quickest way??? When was setting up a Dti gauge quick? Surely if the steering pulls out of his hands during braking it can only be Discs?

Totally agree 100% about the handbrake trick as this is also how you can tell if your shoes need adjusting!

 

they can test it on brake rollers at an mot station takes 5 minutes,they tell when the needles go up and down

 

MOT station will only simulate road driving though mate, Iv'e been MOT'n for 3 years and the rollers won't turn fast enough to give you a good sense of a warp disc, they'll still show good effiency if they are warped.

They'll show up in the rollers if the rears are ovaled, pulsing from the pedal and needles will go up and down!

 

the handbrake trick does NOT work. it doesnt mean a thing. U need to press the pedal, as the pulsating transfers to to the fluid which then travels to the front of the car.

Swap the drums - they're about 40 quid a pair off hand.

 

So how does the handbrake work then? Does it not apply the same shoes that the footbrake does?? Of course it works, i'll explain it SIMPLY

Pull the handbrake slightly up, if the brakes don't grab steadily then that PROVES your rear drums are warped!

 

yes, that is true. But, if it DOES grab steadily - it doesnt prove they arent warped.

The fluid isnt compressed when handbrake is pulled for a start.

 

I use dti's all day at work (areospace tool maker) i could set one up in less that 20 seconds!!!! (as long as the wheel is off of coarse)

 

thats correct but what you will feel is the vibration from the "oval"drums

 

Well no Rick, if they pull up steadily then that means that your Drums are as they should be ROUND!

The fluid doesn't have to be compressed, the only reason the pedal pulses when the rear drums are Ovaled is because the Fluid is acting like a solid object when you compress it, so when the wheel cylinder is pushed back in because of the Ovaled drum, the fluid has to go somewhere and your foot is weaker than the Solid drum!

 

I know the theroies behind it all - ive worked on enuff of em lol. The simple fact is that i have had cars where i have pulled up the handbrake and it feels perfect. However, its turned out that the drums have still been at fault. I simply wont rule out the rear drums untill they are swapped. I learnt the hard way. Friend has a concours car, with everything new from ford. We changed the WHOLE front end, and it still vibrated like mad. Handbrake was smooth. Only thing left was drums. IN all honesty i couldnt beleive it. They're cheap and easy to change though.

 

I suppose i'm just one of these people who won't just keep changing things to solve the problem, I like to KNOW for myself what the problem is then cure it.

 

Rick, you've rebuilt a car - what the hell would you know PMSL

Nos MUST be right cos he's a MOT'n

 

 

What has BHP got to do with the brakes? that setup he has is fine! wehter he has 250hp or 150hp

Unless of course he does the extra 15 mph ish top speed gain into every corner everytime he goes out

 

if your ragging round a 250bhp rs turbo your going to be doing a lot more hard braking than a focus st170 aint ya,so therefore the discs will get hotter and 2 months of hard driving is quite a lot

 

Agree with Paul, For example, A 250bhp RST on a track is gonna be much harder on any brakes than a 150bhp car

 

yeah on track, but if your raging a STD rst around a track the brakes wouldnt be good enough.

For normal road use the st170 are fine imo!!!!!

 

depends what you drive like, i know plenty of people that think theyre out on a track all the time

 

well aye!! LOL!

Im not saying brake upgrades are daft....hell no. I want some for mine,,,i just think people go way over board on them for road use

 

well oranoco why not get seperate bells and discs, ive seen him drive ( been in the car with him a few times too )

yes its hos driving, he does drive like a loon just look at his top speed times for the spec of his car at brunters

hes a fooking animal, hes never at the back of the pack and has a play with anything he sees ( he would race planes if they went low enough



but steve its not all doom and gloom i might have to sell me brembos with discs and bells that have not been finished yet ( my fault not the god making em )

if ya wanna give me backthe money i payed for em then ya can have em

rather help out a car that im gonna be going pout in a few times then sell to a person i dont know for a bit more money

dont see a chipped ecu standard erst engine needing 315 discs with ally bells and 4 pot brembos

not with my driving tbh as i drive like a girl