weird brake behaviour

[tHe1337cHi3f]

Hi everyone, I might need your help with my 2010 Subaru Impreza...

...as I am hoping for suggestions that don't involve a brake job since it is too cold outside for shenanigans like that.

My girlfriend told me about some noise my car was making, suggesting it might be the clutch. As you can imagine, my heart skipped a beat. But the clutch behaved normal, even as my daily is automatic, I know I'd feel if something was off. So I went cruising a bit to find out about the noise. As I live in Switzerland, here is what you do to test a vehicle: You head to the next mountain pass and you damn punch it. You punch it hard. I punched it so hard that my fuel hose slipped off the injection system, anyway, I slipped it back on and clamped it a little harder. I had burned some rubber into 150kms of road when I finally found out it's just the muffler, ok, not too bad, I can check that out later...

... long story short I think like the clamping of my fuel hose, the brakes were not designed for what I did either. Braking from high speeds on my way home on the motorway I had a bit of a vibration (I had test driven worse, like ones that tried to rip the steering wheel out of your hands when braking).

So here is the question, what is the right thing to do?

A) Just drive normally, keep braking softly and the unevenness of the brake discs will shave off. And now hold your horses while driving, will ya!?

B) That stuff's kaputt. Change your brakes and upgrade for some internally ventilated, slotted, perforated Brembo brake systems (that will probably cost more than my bloody car).

Looking anxiously forward to your suggestions.

Ollie

[Master_Scythe]

B.

But you don't need to go to brembo's, any decent vented brake system should be fine.

Are you coming from stock?

If so, I'd suggest DBA T2's, or even EnShield, which is their entry level.
Even though it's an OEM replacement, the cooling is FAR superior to any other brand

https://dba.com.au/tech-zone/product-technology/kangaroo-paw-ventilation/

And it's overheating the rotor that's caused the disk to warp in the first place.

They're probably not dead yet; if you know someone with a lathe you can spin them down half a mm and get them 'good enough' without sacrificing disk thickness (hopefully).

You mentioned a clutch, but then you mentioned an automatic, so I'm not sure what you're driving....
If it's a Manual, then your brakes shouldn't be getting that hot, even performance driving a mountain should only get them lightly glowing.

If it's an auto, then yeah, you'll be riding the brakes a lot more, and i could imagine them red.
You haven't really driven a subaru hard on the mountain until you're putting the brake pads out with your waterbottle have ya? haha, I think we subaru folks have all been in the 'brake pads on fire' club.

Not a lot you can do other than make sure your parts are fit for purpose; if you're going to togue the mountain, then make sure you have parts that can tolerate the abuse.

[tHe1337cHi3f]

B.

But you don't need to go to brembo's, any decent vented brake system should be fine.

Are you coming from stock?

If so, I'd suggest DBA T2's, or even EnShield, which is their entry level.
Even though it's an OEM replacement, the cooling is FAR superior to any other brand

https://dba.com.au/tech-zone/product-technology/kangaroo-paw-ventilation/

And it's overheating the rotor that's caused the disk to warp in the first place.

They're probably not dead yet; if you know someone with a lathe you can spin them down half a mm and get them 'good enough' without sacrificing disk thickness (hopefully).

You mentioned a clutch, but then you mentioned an automatic, so I'm not sure what you're driving....
If it's a Manual, then your brakes shouldn't be getting that hot, even performance driving a mountain should only get them lightly glowing.

If it's an auto, then yeah, you'll be riding the brakes a lot more, and i could imagine them red.
You haven't really driven a subaru hard on the mountain until you're putting the brake pads out with your waterbottle have ya? haha, I think we subaru folks have all been in the 'brake pads on fire' club.

Not a lot you can do other than make sure your parts are fit for purpose; if you're going to togue the mountain, then make sure you have parts that can tolerate the abuse.

Thank you very much. I won't go working on broken shit oem parts since work here in Switzerland is expensive as hell. I could get the best race brakes for the money I'd pay just to take off brakes and replace them. So I gotta find myself a shed or something and do it myself.
I probably will, like you suggested fit some entry level brakes since I'd rather exchange them now than learning after an accident that they were not fit enough. Even though I don't go driving in the mountains a lot (yes it's automatic because I daily it in dense traffic) brakes are an absolute necessity.

Thanks again and have a great day!

[Master_Scythe]

work here in Switzerland is expensive as hell.

Australia ain't cheap either for work; but machining brake rotors are something that's done at a lot of regular services.
Surely it cant be much more than $100 or so?

It's often worth trying once, and seeing if the brakes re-offend, because metal has a shape it WANTS to be in, and once the heat has warped it into shape, sometimes it'll stay there.

[tHe1337cHi3f]

Australia ain't cheap either for work; but machining brake rotors are something that's done at a lot of regular services.
Surely it cant be much more than $100 or so?

It's often worth trying once, and seeing if the brakes re-offend, because metal has a shape it WANTS to be in, and once the heat has warped it into shape, sometimes it'll stay there.

I've seen offers ranging from 300 CHF which is around 460 AUD. Maybe if I disassemble the brakes myself and come only with the discs it might be a lot cheaper. But I'd still pay money for that. And it won't prevent me from getting the same problem again. And if I spin them down they will heat up even quicker.
So I am in the market for an upgrade now. I checked for DBA brake systems, but I can't get those past inspection since they apparently don't come with necessary paperwork for switzerland (TÜV on steroids).
So I am now looking at a mighty list of different parts from bosch over brembo, rodex nipparts zimmermann whatever the **** those brands are called. I gotta sort that out now

Edit: Since no shops are open on Sunday I took it for a spin and it turned out the discs were not deformed but they had brake debris burned into them what caused the wobbling, saw the marks in the sunlight. I forgot to take photos but some 50kms on the motorway with regular (civilised) braking shaved it off. The brake discs look brand new and behave like they should. I love problems that sort themselves out!

[Master_Scythe]

Curious;

So I am in the market for an upgrade now. I checked for DBA brake systems, but I can't get those past inspection since they apparently don't come with necessary paperwork for switzerland (TÜV on steroids).

Can't you just clean off the brand, and carry some other brands paperwork?
It's literally a metal disk... how would they ever know?

Also, right, so it's the pads that weren't rated for the heat then; now you know what needs replacing
At least it works in the mean time.

[tHe1337cHi3f]

Can't you just clean off the brand, and carry some other brands paperwork?
It's literally a metal disk... how would they ever know?

I could, but I'd commit "wrong certification" which is a little less worse than "forgery of certificate" and I'd be facing jail time. I'd probably get away with monetary punishment (which is still worse than a fine) and I would be a registered felon. No way I risk that over some brake discs. And they would know if I ever were involved in an accident, they check everything in that case.

So I'll change the brake pads, which is a little easier than the whole discs and I am really glad for that! And I am also glad that I gained some time!

[tHe1337cHi3f]

Update to my story:
The brakes were completely shot, had to open the entire brake caliper with a flex. So I redid them and sold the car. I needed something that can handle my "weekend driving" which i got now

[Kaktus]

Sounds interesting, what did you get?

[tHe1337cHi3f]

It's a Yaris 1.5 l TS Turbo. It has 150hp but weighs only around a ton. This makes it very agile and great fun to drive.

In 2004 Toyota engineers came to switzerland and built 600 of them, so they become quite rare.

[Kaktus]

Oooh lovely!!! That is actually one of my favourite Toyotas, I’d love one of them! Can’t really find them here in Ireland, and with the whole B-word across the water in the UK means I missed the boat on eventually importing one from there. My current daily is just a bog standard ‘03 3-door Yaris 1.0 litre but keeping an eye out for a mint 1.3 litre ‘04 or ‘05 Yaris. Brilliant little cars!

[tHe1337cHi3f]

They are so frequent around here, also a 1.5 litre. The turboed ones are already going up in price, but you can still get them. Shame that the import to the UK became so complicated, I'd love to keep an eye open for you.

But yes, it's a great car, sturdy but still light. It fits surprisingly much luggage, we went to Florence this summer in it. The only thing that sucked was that the AC gave up and it was 38°C. I gotta take care of that

[Kaktus]

Up until a couple of years ago Irish drivers privately imported about 100k cars from the UK to Ireland each year, but that’s pretty much died now when 23% VAT has to be added on top of all the other taxes and duties making it not a viable option anymore. A shame Ireland drives on the left, otherwise I’d buy something interesting from mainland EU.