Brake Judder

[tinman1]

Hi Folks

Looking for a little help if you can

I have a 2001 Newage Scooby Estate WRX (first of the bugeyes) and I have been struggling with a symptom that I have almost submitted to now, that the car has had ever since owning it.

The symptom is brake judder, but before you all go leaping in and saying that the discs are warped; please allow me to explain.

Purchased the car in 2009 and after getting use to it, I started noticing a mild brake judder.

Now it was not, nor is not to this day; severe. In fact it is very mild and only at a relevant speed range and at a certain brake pedal pressure

The car had had an arduous amount of work carried out on it at the dealers expense prior to purchase and while under warranty.

(again please understand, we did not purchase a lemon, we have in fact purchased a car that firstly was so enjoyed by the owner. He has in fact purchased a newer model. and secondly he did look after the car, as it only ever went to the dealership for maintenance, but did obviously skimp in his final couple of years of ownership.)

ie. door speaker not working, did not have replaced

Door seal air noise, did not have replaced

etc etc etc

Think he just reached a point where instead of puting significant money in to a 9 year old car; figured he would just purchase a later model WRX, (fair play :-) )

Nothing major or significant, and all was replaced by dealer before or during warranty, due to me recognizing it at point of test drive.

Just to put you in the picture, (as some of you know) I am a 20 plus year Automotive engineer, now retired from the tools. (design is now my thing so watch this space, :-) in the future)

Symptom occurs when braking with significant pedal pressure and the speed while braking reaches 43 mph, but disappears at 40 mph. It can at times have a very mild effect on the steering wheel, (not problematic, just annoying) An un-tuned in driver may not in fact recognize this.

Prior to purchase vehicle had new discs and pads all round, fluid etc. And had in fact only covered approx 500 miles max since fitting at point of test drive.

Initial thoughts were, get the wheels balanced. SO did this. Improvement was 90% better. Even though discovered during wheel balancing, the vehicle had a buckled front wheel. Had it fitted to rear temporarily. and have replaced buckled wheel with replacement item from breaker and did check it for being true prior to fitment.

As time has gone on symptom has remained and so:

Thus far I have replaced the front discs. No change

Replaced all brake pads with EBC Red Stuff Items, and for all that has improved symptom significantly, has not remedied.

Have measured run out of hubs, All OK, have four wheel alignment done OK.

Have read that there is a number of recalls for the vehicle regarding braking system and more, and thus have contacted a UK dealer, (No channel Islands dealer anymore) who has been awesome, considering they are not getting paid for their efforts. ( Proven Subaru in case you are wondering)But am informed all recalls for my vehicle have been performed (according to the system ???). Only outstanding recall is the bottom arm recall (ref top gear, failing bottom arms) AM replacing with Aluminium items this weekend so issue eradicated !!!

So; My Question is,

Given the extensive knowledge and experience of many a member of this club, which can often out-way that of a decent dealership;

Has anyone got any ideas, knowledge, experience of such a problem?

And if so, did you find a cure to the problem and what was it if you did ???

My apologies for such a lengthy post and I am sorry to take up your time if this is not your thing, but I am about ready to accept this symptom as an inherent feature of my particular car (short of contacting Subaru ?) don't know if they will help given that she is 77000 miles and 12 years in now ???!!!

Sorry, forgot:

Car now has later updated steering rack (due to chattering noise and feel through steering wheel when on uneven surfaces such as concrete multistory carpark floors (now has revised rack with larger input shaft bearing. (also found input and output PS pipes loose during replacement and so have ensured tightness on new rack. Also ensured tightness of pump pipes to prevent air scavenge.

Link bars have been replaced

Also had four new tyres 14000 miles ago (that is since noticing Problem, ie since owning the vehicle, and they are still in ery good condition Khumo Ecsta LE Sport, standard rims) Soon to have FOX FX004 8x18s

Any suggestions welcome, in fact I invite them

My Kindest regards to you all, and hope you all are in good health

[Bryan d]

Ok this may sound silly but when you changed your pads did your pistons push back nice and easy cos I went o the flig we the boys on hear and upgraded the brakes to 4pots for better brakeing lol and found when above 45 got a judder thrue the steering wheel and when higher up the speed got worse so Thot discs the pads wer needing done so fitter ebc red stuff pads and that's when I found a sticky piston had a wee bit of rust on it gave it a clean we emery paper fine grit clarted on the copper grease then tryed agen went back so smooth and with little pressure on ma leaver

Hope that helps and if not hope you get to the bottom of it

[lewisscoob]

^^^what he said. You should be inspecting the freedom of movement in the caliper pistons.

[tinman1]

Ok this may sound silly but when you changed your pads did your pistons push back nice and easy cos I went o the flig we the boys on hear and upgraded the brakes to 4pots for better brakeing lol and found when above 45 got a judder thrue the steering wheel and when higher up the speed got worse so Thot discs the pads wer needing done so fitter ebc red stuff pads and that's when I found a sticky piston had a wee bit of rust on it gave it a clean we emery paper fine grit clarted on the copper grease then tryed agen went back so smooth and with little pressure on ma leaver

Hope that helps and if not hope you get to the bottom of it

Thanks for taking the time to reply Bryan and lewisscoob

I can confirm that the pistons are/were free in the calipers and that they returned in to the caliper with no problem when fitted the EBC Red stuff pads.

But just to double check, I will look this weekend as I am replacing the entire front suspension (not for the braking symptom ) Because my top mounts are perished and have started knocking. so built up a set of new struts with new TMs and am also fitting Aluminium bottom arms to eradicate the lower arm failure issue (top gear Hammond's lower arm failed ! Its a recall outstanding on my car.

Will let you know.

Ironically my model car comes with the Subaru 4 pots, so I am presuming the are what you fitted Bryan ?

Cheers guys

Edited September 11, 2013 by tinman1

[Bryan d]

Yes I fitted 4 pots coss I got my car remaped and got 339 hp and the guy sed it should b the next mod that I do lol

[tinman1]

Well as promised I am posting the result of my findings with regard to brake judder.

And I can categorically say that after 7 painstaking hours of investigation and

component replacement,

Lower arms for aluminium (inc all bushings)

Struts due to age

Strut tops due to RH knocking

Front discs due to crack found in LH inside

Link bars to suit lower arms

Brake fluid due to age

Clutch fluid due to age

And investigating the caliper pistons for free operation, (takes a deep breath and pauses for a moment)

The fault is still there and there is no significant reason why it should be Incidentally, the pistons in the calipers are free and free of any visible debris/rust, thought you may be on to something when I pulled out the inner left pad as it was imediatly visible to me that it was slightly thinner at one end. Vernier calipers showed 0.7 mm difference but the pistons are clean and free in operation

Have attached pictures of the crack found just in case anyone was interested.

So

The car has had:

Wheels checked for being true

1 x new wheel due to warpped

Hubs (x4) clocked for runout

2 new sets of front discs

new pads (red stuff) all round

New set of tyres (4)

Lower front arms

New struts

New springs

new strut tops

New ARB link bars

New ARB bushes

Wheels torqued to see if it would make a difference (as aposed to a very experienced right arm)

Wheels and tyres rotated

wheels a tyres balanced twice

And this is only the items that relate to the front end, and I have owned it 3 years and covered 20,000 miles in that time.

Think I need to speak to the previous owner and get some history on the car.

Like how bad was it crashed when the rear left wing was painted and the front right wing as well?

If anyone can think of anything, please feel free to speak up.

As before, all ideas/advice welcome

Sad part is it really is not so bad, most average drivers would not notice it in normal operation. I'm just a fussy twat and won't give in.

Oh well, will keep looking.

TTFN

Thanks guys

[tinman1]

Just spoken to previous owner.

Car had 400 miles on clock when he purchased and has never had a crash while owned by him, (to his knowledge.) neighbor bumped in to rear left door so had new door skin, so that may explain the paintwork on rear left side. (Door and rear wing)

Subaru paintwork is crap anyway so front right wing inside bonnet may just have been missed at factory.

Was however a demonstrator and after owning the car for 12 months car was in need of four tyres and a wheel alignment. Nothing really conclusive there though either. May be that he/wife knocked a few pavements and buckled the wheel. (or done while in for service and covered up ??? )

SO the investigation goes on.

Think I will speak to Subaru !?

Nothing ventured, nothing gained.

Anyone have any experience with Subaru UK tech dept ?

Are they good or bad ???!!!

TTFN

Will keep you informed.

[mctwistuk]

Hopefully you will get to the bottom of this.

Chris

[Bryan d]

How's the groves and drilled parts in your discs I cleand them out we a plane screwdriver but I take it by the crack you will b replacing them lol have herd thay crack on the groves to just a Thot lol

[tinman1]

How's the groves and drilled parts in your discs I cleand them out we a plane screwdriver but I take it by the crack you will b replacing them lol have herd thay crack on the groves to just a Thot lol

There fine, they are only dimpled not drilled all the way though, went for dimpled and grooved because drilled have a history of cracking at the drilling. they were fine though. Always kept an eye open for clogging, they never have.

And in the defense of the crack. I have had them glowing at times, so I think they have fared well for a set of discs that have had 15,000 miles put on them given what they have been through. Only cost me £65 new so can't complain. Put standards back on for now, thinking on moving up to Brembo all round.

[tinman1]

Hopefully you will get to the bottom of this.

Chris

Cheers Chris, sure I will one day

[spect]

It still sounds like steering to me still, maybe a bit of play somewhere in the system? It is an odd one indeed.

[tinman1]

It still sounds like steering to me still, maybe a bit of play somewhere in the system? It is an odd one indeed.

Hi Spect, thank you for taking the time to consider my issue.

New rack, Updated version due to old rack having the proverbial play in the input bearing shaft. ie inadequate small bearing so changed for a new larger bearing input shafted version.

No play in ball joints or steering rack ends. found pipes loose at point of change so ensured tightness with new seals on pipes and new seals and banjo bolts on PS pump, Scavenge was recognized and thus ensured eradication by way of new seals and banjo bolt weirdo seals. Blooming expensive. £10 for a bolt !!!