Technical yet more brake probs

[Drinu]

hi there guys,
well about 2-3 months ago I had my front discs changed and I also changed the front pads as well. Well....at first the brakes were almost useless, but that is normal I guess until there are run in. After about 10miles of driving they were fine. However and I noticed this last week, whenever I break the car stops with a judder sort of. I dont know how to explain myself but it's like braking force is not constant. Its like pressing and depressing the brake pedal in fast succession. I was thinking that I had warped brakes but could it be that they warped just after 2 months!? Could it be something else rather than warped discs? remember the car used to drive well until last week.

 

[custard]

could be warper discs.remeber its not always a wear issue.
eg a guy at work had a slightly binding brake so 'cooled' the brakes by going through puddles.
warped disc!
is weird having been fine but i think you need have the wheels off for a looksie to check for a lose caliper etc

 

[Peterg]

Check the disc is mated flat against the hub.
Jack up the car and spin the wheel to see if you have any sticking points.
Ensure the pads and discs are all clean from any debris etc that may cause scoring.
Pete

 

[Drinu]

ok thanks guys,
i will check it out next week coz at d moment I have exams. What I was wondering is if there is an adjustment for the calipers! I mean is there a bolt or nut which is used to adjust how far in or out the caliper is placed. Also is there a way of opening the distance between the calipers!?

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[custard]

you cant move the caliper.well you could with wahers but thats no the solution.the caliper should slide on its own mountings.
get back when you see what its like

 

[Drinu]

hey guys,
exams are over....and I now removed my wheels to check the brakes if they are warped....well guess what...they're not!:S

What else could the problem be??

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[custard]

i would strip them down and clean the hub face.also clean all the mating surfaces for the pads and make sure the slides are not seized

 

[M@nticore]

Check your front wheel bearing play, I had that once on a 1400 uno, replaced the discs and pads and the problem was still evident. Renewed the right hand side bearing and the car was sorted.
If your discs are a blueish colour I would suggest replacing them, and only use a decent brake disc like alfa etc.

 

[M@nticore]

Forgot, check your front tyres aswell, for out of round or uneven wear, what I would suggest is to put your rear tyres upfront and front at the rear and take it for a test drive.
And check your suspension, and it's bolts, like worn tie rods etc.

 

[Drinu]

hey M@nticore thanks for the tips...I checked all the above and all is in place. Tyres are still in good nick and everything else you mentioned is in place!

I booked it in the garage next Tuesday afternoon. I told them about it and thought it was strange. They said they will try and look for the problem but dont know what to look for. We'll see what happens

Will keep u updated through here!

 

[Drinu]

well here is an update. took it to the mechanic and he couldnt find anything wrong with it...all seems to be in place..all bearings are ok suspension ok wheels and tyres ok...discs are clean and NOT warped....pads seemed ok. We decided to change the pads ie left to right and right to left but kept the same ones for each wheel. We tested and its ok...but now it seems to be back again...however this time the vibrations are in faster successions!!

Does this help?? I mean anyone have anymore ideas!?

 

[(CZ)enda]

Another logical step seems to swap left and right pads and see what it does...
Cleaning and copper-greasing the surface on the caliper where they move and their securing wedges...
Possibly buying a set of new pads...

 

[alexGS]

I agree with (CZ)enda - sounds like it may be time to try another new set of pads. I really still suspect the discs - were these checked accurately?

-Alex

 

[Drinu]

well the pads I have are only 3 months old. Dont want to go and buy new ones (im still a student at uni and have no income!). Do you think I am doing damage to the car if I leave it this way for a while!? What I mean is, am I straining any mechanical parts in the car this way!?

 

[(CZ)enda]

I do not think you will damage anything, but I would not want to drive a car with doubtful brakes.
Swapping the L/R pads will point on whether they are faulty. If the remedies offered above make no difference, I suggest trying to go to where the discs were changed and complain loudly as I agree that they are more probable culprits than the pads.
You should have 2 years of warranty for them - let the workshop deal with the issue.
Some people have warped discs machined, but I never bothered with this as the price of machining is about 1/2 the price of a pair of brand new Brembo discs where I live and I did not think it was worth the fuss of having to argue with a workshop should they machine them wrong.
The only other, rather theoretical, possibility I can think of is worn lower balljoint/wishbone mounts, but this would AFAIK cause the car to "snake" while braking, not judder.
Other than this, I can only think of suspension - faulty shock absorber (IMHO this is extremely improbable).

 

[e_cag]

You can check inner side of rear drums which affects the entire brake system if they were worn on where the shoes press.

 

[Drinu]

I doubt its the rear brakes as when I tried stopping with the handbrake it didnt do it! I now changed left pads for right ones and it does it only sometimes. I will use these pads a bit more since they are still new....then I will change them just before the VRT.