Technical Brake pedal vibrating

[marlar]

My Punto 1.2 from 2002 (don't really know if this Mk1?) has recently got a problem with the brake pedal which has started to vibrate or judder.

There has been several similar threads in this forum, but in contrast to the other threads I have seen, the vibrating so far has only happened at very low speed, like when just starting the car og when turning. That is at least a bit reassuring.

It feels very much like when ABS is activated.

The car has just passed the biennial mandatory check a week ago but I still am a bit uneasy.

What could be the cause?

 

[blu73]

2002 is mk2, i have moved it to the mk2 section for you

 

[AndyRKett]

Unless it’s a top spec model a 2002 is unlikely to have ABS (assuming back in 2002 Denmark didn’t require all cars to have it by law)

If it’s most noticeable at low speed then it’s likely to be something fairly simple like a warped brake disc.

 

[Ziggy122]

If its abs activating falsy - say due to a cracked tone ring
Itd be activating at all speeds till a near stop

Dont deny drums causing an issue either (been ovaled by been hit on aide to remove them)
You can check by applying handbrake gently/pregessivly to feel
If its only under footbraking - most likely fronts
Ensure back of disc and hub faces are spotless too as this can cause warping

But if the disc has excessive runout(warping) then its a mini front overhaul


Ziggy

 

[multipete]

Had it on a Meriva,when first applying the brakes,the abs would cut in,then the abs would turn off,and the abs light came on,that was due to a cracked abs ring.

 

[Scudmonkey]

Discs and drums are fairly cheap to buy for Punto. I just replced both discs and both drums with Brembo ones and total cost was just over £40

 

[s and b]

if car does have abs then possibilty is extreme pressures used to check brakes on test have caused the problem
ie rear brake adjusting rod has fallen free thus causing abs to trigger
if it is this i suggest drums off to investigate in case a wheel locks up

 

[marlar]

Thanks for all your comments and suggestions.

I went to my mechanic and he said it was some cracked or bent rings for the ABS system.

He was going on vacation so he couldn't fix it right away. Instead he simply removed a fuse for the ABS and now the brake behaved normally.

Of course we will need him to fix or replace the rings, but for now this is fine since the weather is nice and dry and ABS is not that important at the moment.

 

[Ziggy122]

Thanks for all your comments and suggestions.

I went to my mechanic and he said it was some cracked or bent rings for the ABS system.

He was going on vacation so he couldn't fix it right away. Instead he simply removed a fuse for the ABS and now the brake behaved normally.

Of course we will need him to fix or replace the rings, but for now this is fine since the weather is nice and dry and ABS is not that important at the moment.

Rears are built into the rear hubs
A very simple swap
But its a bew wheel bearing so a little but of dosh

The fronts i believe are bearing based? Never really looked at an abs punto (soo many without)

Ziggy

 

[AndyRKett]

New rear wheel bearings needed about £30~ each

Fronts are a similar price but need to be pressed out of the steering joint, not an easy replacement like the fronts.

You might only need one on the back it’s unlikely to affect more than one wheel at a time but you never know I suppose, if you have a nice garage and it’s a straight forward job then you might pay £50-100.

The brakes will work like normal brakes without the abs fuse being in, however you must bear in mind that if you have an accident abs helps by allowing you to steer round things without skidding, brake too hard at the moment and you will just skid, if you had an accident then you may be liable personally and your insurance void as you knowingly drove the car with a defective braking system.

People get carried away on hear quoting the law, but this could get you a fine and have to have he car MOT’d again if the police stopped you, at worse if there was a fatal accident it could mean a jail term for manslaughter.

The decision to drive like this, is very much yours to make but it can carry a hefty penalty and really you shouldn’t drive it

 

[marlar]

I just noticed that I didn't follow up on this.

I drove without the fuse for some time, then I inserted it again.

And to my surprise, everything was normal. Not the slightest vibration anymore.

Never found out what caused it.

Now a year later it still works!