[ohwreg]

I just took my car for a quick "Health check" to the local Hyundai dealer and they said it was perfect. In the video they sent me, however, I noticed that the rear brake discs are quite corroded and only have a narrow band clear on them, while the front seem brand new. They did say that the brake pads are non-genuine, are lacking the anti squeal shims and are 10% worn.

Is this normal for i30 GD or is something wrong with the rear brakes? Thanks

Pictures: i30 GD 2016 brake discs - Album on Imgur

[sundiz]

Looks just like stuck rear pads. Happens easily in your climate. Not a brand/model related issue.

If the pads are in 90% condition, they are fairly new. They might be badly assembled and got stuck. Or the issue has been with the previous pads and they have only changed the pads, when they should have changed pads and discs. My money is on the second case. If the discs are not badly worn, you might be able to get them work by first making sure the pads move easily and do some harsh braking. If that don't work you might want to get new discs and pads to rear.

[ohwreg]

The car has remaining warranty to Jan 2021. Do you think this is covered?

[sundiz]

No. Brake parts are not under warranty. They are supposed to wear.

[Lorian]

how many miles has the car done in he last 6 months - has it sat a lot during lockdown?

Also do I see a bit of a grease leak from the front glide bolt rubbers - might be worth eye baling the seals and make sure they haven't been "jet washed"  out of round,  but I'm sure the dealer would have spotted it.

[ohwreg]

I just bought it 2 weeks ago but I believe it had been sitting for a couple of months just before that. The dealer did give it a wash. I noticed the wheels were much shinier so perhaps that's the liquid you see.

I will give it some time now but will ask the mechanic to assess them at the next service. It will be an independent mechanic since the warranty is expiring and 400 quid for a service at Hyundai seems a bit too steep.

[sundiz]

If the car has been standing outside for a long time then you should do hard braking. Just make sure it is safe to do and no one is right behind your rear bumber. Maybe an empty road or parking lot. Brake discs get surface rust if not used. Rear brakes do not work a lot in "normal" driving. If the discs don't clear up,  they will become an issue in MOT at some point. Uneven wear will cause uneven brake power.

[ohwreg]

Thanks! Can you give me some benchmarks for what hard braking as troubleshooting is? Are we talking full brake at north of 40 mph?

[Lorian]

40 ish to nearly 0 hard 6 or 8 times over the space of a minute or two. Like as if a dog runs in front of you.

when its safe to do so of course - nothing around  - ideally a straight country road.

They don't get nearly as much pressure as the fronts so they will always look a bit duller in our climate.

[sundiz]

Drive it like you stole it

[BrendanP]

When I replaced the rear pads on my car I bought genuine Hyundai pads and they were supplied with new shim plates, which are the thin steel plates that clip into the yoke that holds the pads on either side of the disc. I also have some Pagid pads that supplied new shims, but some brands like Bendix don't. I always take the yoke off and clean off any rust and scale behind where the shims fit. Anything that stops the shims seating properly means there's less of a gap for the pads to slide in, so they may stick. I also clean the shim plates as best I can (if re-using the old ones) In addition, if the pads are cheap and nasty the dimensions of the backing plate may not be within tolerance so they don't slide as they should, in which case a bit of judicious filing may be needed.

[wbm00]

No. Brake parts are not under warranty. They are supposed to wear.

FYI I had rear calipers, discs and pads replaced under warranty. Apparently the problem was faulty rear calipers causing brakes to 'stick'. Still having issues with brakes sticking again...

[Dazzler]

No. Brake parts are not under warranty. They are supposed to wear.

FYI I had rear calipers, discs and pads replaced under warranty. Apparently the problem was faulty rear calipers causing brakes to 'stick'. Still having issues with brakes sticking again...

That's a pain. Great to see you back and posting I've missed you! 

[sundiz]

FYI I had rear calipers, discs and pads replaced under warranty. Apparently the problem was faulty rear calipers causing brakes to 'stick'. Still having issues with brakes sticking again...

That is good to hear (the first part). At least you got one set of new brakes. These consumables, brakes, fluids, sparkplugs, fan belts etc. are not normally include in the warranty, unless there is some abnornal failure. When GD was serviced, they took the brake pads out, cleaned contact surface and put back in at normal service. That was a postive suprise.