Brake Pads & Discs

wardides

I was wondering if somebody could help me out here.

In the middle of June my ABS light started flashing on my car. Brought to a well known independent mechanic(my own mechanic was away). He replaced the brake pads & shoes ( I think that's right, misplaced the receipt).

In the past couple of weeks the steering wheel has began to shake (nothing major, just a slight vibration) when I brake from a high speed (80-120). Brought the car in for a service on Saturday, and all was well apart my mechanic informing me that the pads wern't straight, hence the slight vibration as it was resistance from the front brakes. He said this may because around the discs/shoes wern't cleaned properly when changed or wern't put in straight.

My question is, would it be naive to think that I could go back to the original mechanic and ask for them to be looked at again at no cost? Aware it's a few months since, but been told that there is probably nothing that could have happened since to result in the pads moving? Any thoughts would be appreciated!

5W30

Sounds like warped discs. Are you sure he changed the discs?

wardides

5W30 wrote: »

Sounds like warped discs. Are you sure he changed the discs?

It could have been pads & brake shoes. Because I'm an idiot I've lost the invoice.

5W30

wardides wrote: »

It could have been pads & brake shoes. Because I'm an idiot I've lost the invoice.

Yeah it seems strange that the mechanic suggests the pads are the problem.

If the pads were uneven they would even out over time.

Vibrations are caused by warped discs.

biko

Does brake pedal pulse when braking?

A mech can put the car up on a lift and feel for imperfections while wheel rotates.

But yeah, take car back and let them have a look. I can't say it will be free as everything was fine for months.

mullingar

I have found that cheap discs can warp in weeks, all depends on how they were used. If you are more of a spirited driver or have braked hard in puddles, the metal would have expanded/contracted non-linearily and are now warped.

The usual fix is replace the discs (or skim them if they weer expensive)

ironclaw

You'd know by the cost of the initial service if he replaced the disc. It would be considerably more than just pads / shoes.

CiniO

It's a common problem OP.
Warped discs.
Very often mechanics use cheap replacement parts (discs) and they are so bad, that they warp very easily. Sometimes it's enough to brake more heavily (which heats up the discs a lot) just before driving into water puddle, and this can warp even new poor quality discs.

5W30

I'm still wondering how the mechanic thinks that "the pads are not straight" :pac:

wardides

The initial mechanic charged me 380 quid. Had me for an absolute idiot, and basically I had my driving test 2 days later (ABS light was showing which was why I went to go get it checked) and as a family friend I didn't think he would take the piss.

Maybe best to ring him and ask him, appreciate all the replies on here though!

5W30

wardides wrote: »

The initial mechanic charged me 380 quid. Had me for an absolute idiot, and basically I had my driving test 2 days later (ABS light was showing which was why I went to go get it checked) and as a family friend I didn't think he would take the piss.

Maybe best to ring him and ask him, appreciate all the replies on here though!

€380 should include brake discs too!

There's 2 possible scenarios now:

1. The replacement brake discs were of poor quality
2. The brake discs weren't replaced at all but you were charged for them

CiniO

5W30 wrote: »

€380 should include brake discs too!

There's 2 possible scenarios now:

1. The replacement brake discs were of poor quality
2. The brake discs weren't replaced at all but you were charged for them

But how would that explain the vibraions? There weren't any vibration beforehand.

I'd say it was just disc of poor quality, and they got warped straight away on a first water puddle. Common thing to happen on cheapest discs.

5W30

CiniO wrote: »

But how would that explain the vibraions? There weren't any vibration beforehand.

I'd say it was just disc of poor quality, and they got warped straight away on a first water puddle. Common thing to happen on cheapest discs.

Simple.

The brake discs wear down over time below minimum thickness and the chances of the disc warping increase dramatically.

CiniO

5W30 wrote: »

Simple.

The brake discs wear down over time below minimum thickness and the chances of the disc warping increase dramatically.

OK. I didn't know that.
I didn't actualy think it would make that much difference, as range between new discs and worn discs is not that big. F.e. for my car new discs have 24mm, and borderline when they are worn is 21mm (so it's only 3mm difference).
Would that affect liablity to warping that much?

wardides

So am I right in assuming I'm going to need new discs again? Surely for that type of money new brake discs should last me longer then 4 months? Considering I do about 2000km a month?

mullingar

I destroyed a cheap set of discs in 500 miles with bad warping. Swore never to get cheap discs ever since. I now only buy EBC brakes

5W30

CiniO wrote: »

OK. I didn't know that.
I didn't actualy think it would make that much difference, as range between new discs and worn discs is not that big. F.e. for my car new discs have 24mm, and borderline when they are worn is 21mm (so it's only 3mm difference).
Would that affect liablity to warping that much?

Warping is caused by excessive heat. Skinnier brake discs will heat up quicker. Keep in mind it's not only 3mm of metal that is gone but it's a whole surface of 3mm.

This is why you mostly see old discs warping and not new (if you always buy high quality brake discs).

wardides wrote: »

So am I right in assuming I'm going to need new discs again? Surely for that type of money new brake discs should last me longer then 4 months? Considering I do about 2000km a month?

See previous posts. Either the mechanic didn't change them or he used poor quality brake discs. I would expect brake dics to last 50,000 miles on average so something is not right.