Mazda Dealer & their "duty of care" vehicle inspection

DoaM

Goudy wrote: »

You might want to consider new discs on the rear, although they don't do anywhere near as much braking as the front so don't wear as quick, they rarely get hot so tend to rust up quite quickly and depending on how they are, you could be looking at repeating the same mistake as the fronts.

On my (fairly new - 67 plate - company car) Insignia Grand Sport I had a brakes problem ... it was the rear pads had fully worn and scored the discs. Front pads and discs were fine. (The 2nd service came a couple of months after the rear brakes were done and reported no issues with the front brakes).

My boss had the previous model Insignia and he said he had the same problem ... rears went way before the fronts. Perhaps the Insignia has a greater rear brake bias than other cars?

Goudy

DoaM wrote: »

On my (fairly new - 67 plate - company car) Insignia Grand Sport I had a brakes problem ... it was the rear pads had fully worn and scored the discs. Front pads and discs were fine. (The 2nd service came a couple of months after the rear brakes were done and reported no issues with the front brakes).

My boss had the previous model Insignia and he said he had the same problem ... rears went way before the fronts. Perhaps the Insignia has a greater rear brake bias than other cars?

I doubt it, you'd probably lock up the rears and crash the first time the brakes were applied.
It's more likely the calipers and discs weren't the best quality from the factory.

It's not uncommon for rear disc brakes to drag a bit, as written they just don't get hot like the fronts and tend to rust and pit, this causes the pads and discs to wear really quickly.
You can often hear/feel them the first time you brake after a night of heavy rain, they scrape.

Plus modern tech like automatic electronic parking brakes and hill hold function tend to increase wear on the rears as they release by driving against the brakes when they are firmly on, so wear a little quicker.
You don't tend to do this with a manual handbrake unless you're stopped on a really steep hill, the electronic tech tends to do it every time!

The last two new cars I bought soon started howling from the brakes particularly in reverse as they were dragging badly.
The dealer just shrugged and said they all do that, so I stripped them down to have a look and it was very clear the calipers were devoid of any lubrication on the sliding pin, they were built totally dry.
A quick clean and a smear of high temp grease in the right places and the issue went away, needless to say I did the fronts as well.

I tend to do the brakes myself, I've watched dealers and quick fitters replace brakes and that's just what they do. No cleaning, no greasing just swap out the parts.
I'd rather know that they're done properly with quality parts even if it means I have to get my hands dirty.

AdrianC

Robby1988 wrote: »

Not wanting to make the same mistake again re: changing the pads and not the discs, it seems I could be looking at replacing the discs & pads all round in order to be able to get it done & forget about it. In addition to two new tyres.

Don't you just bloody love cars :mad:

Both discs and pads are consumables, as are tyres. But it's simply down to different wear rates between discs and pads.

Pads wear faster than discs. Discs normally last for a few sets of pads, but by how much varies - I've had cars that have needed them every couple of sets, many last longer.

Once discs start to wear, they're no longer mirror-flat. New pads on old discs quickly wear to "fit" the disc. In the initial wear, when they're only making contact with a smaller proportion of the face, they may wear the high spots on the disc more, flattening them a bit.

Put old pads on new discs, and the pads will wear flat again to meet them, but the initial wear may well be on the discs, too, mirroring the old grooves and shortening their life.

Every disc has a permitted minimum thickness - quite often, that's not a lot thinner than when they were new. There's a myriad of reasons, including heat dissipation. I've had cars where you really could tell when the front discs were getting thin, simply by how quickly fade set in when using the car fairly hard.