March 13

2010 Audi S4 Brake Wheel Bearing Replacement



Mark: Hi, it's Mark from Remarkable Speaking. I'm here with Mr. Bernie Pawlik. Pawlik Automotive in Vancouver. Vancouver's best auto service experience, 24 time winners of best auto service in Vancouver, as voted by their customers. And we're talking cars. How're you doing Bernie? 

Bernie: Doing very well. 

Mark: Today's victim is a 2010 Audi S4 brake and wheel bearings. What was going on with this vehicle? 

Bernie: So the owner had left the vehicle sitting for a couple of months and started driving it. And he noticed that when he would be driving it, especially on higher speeds, there would be this sort of thumping, clicking kind of sound that he figured was kind of coming from the back of the vehicle. So that's how the vehicle came into us. And that's what we proceeded to look at.

Mark: So what's your procedure for testing and diagnosing something like this? 

Bernie: Well, of course asking the client or the driver of the vehicle questions is the most important thing. When does it happen? What speed? And if you're listening to this podcast and you're going into an auto repair shop, when you have a concern or an issue with a vehicle, it's really important to define what speed does it happen? Is a car hot? Is it cold? Where do you think the noise is coming? 

I mean, sometimes it's not coming from there, but at least your impressions, the driver, is really important to know what may have brought the issue on. You know, sometimes maybe you went and filled the gas up and the engine's not running right. So there's various things and these are useful bits of information. So in this case what was involved next is a road test on the vehicle to actually confirm the vehicle's issues. 

Mark: So what did you discover after the road test? 

Bernie: Well, I actually road tested the vehicle myself and drove it out in the highway because it said it would happen on higher speed. It's a standard, so I guess I was, you know, driving it and shifting gears and not really touching the brakes. But as soon as I hit the brakes, I noticed this horrible clattering and shuttering in the vehicle, like horrific actually. Which wasn't really described to me. If I would've described this to somebody, I would've gone, it makes a horrific noise when you hit the brake.

So that's what I basically found. Also, when you get up to higher speeds, I could hear a humming sound in the vehicle. And figured there's probably some wheel bearings that were either gone, either that or there was a tire noise, because tire noises and wheel bearings can sometimes sound the same, but it sounded more like a wheel bearing noise.

So after that, headed back to the shop to do some further inspection knowing that there's a definite brake thumping issue and a wheel bearing concern. 

Mark: And what sort of repairs did you do? 

Bernie: Well, I'll talk a little more about diagnosis first. So the next step, of course, of the diagnosis, bring it into the shop, put it up on a hoist. For wheel bearings, this is a great vehicle to test for wheel bearings, cause it's all wheel drive. We can run the vehicle up on the hoist and we can get the vehicle up to a good speed, drive it at a good speed. And then with a stethoscope we can list all the wheel bearings. We found that the two front wheel bearings were quite noisy and needed to be replaced.

And then as far as the brakes, it was pretty obvious when we looked through the wheels that the brake rotors were very badly rusted. And pulling the wheels off and doing a further inspection confirmed that. Basically the brake rotors had severe rust, especially the rear ones, which was causing the thumping. The rotors are generally a very smooth piece of metal. And as you push the brake pads against the rotor, you have that smooth steel, it stops well. With the rust it causes a thumping. So I'm gonna get right into some pictures. And then we'll talk about repairs done. 

So there's the vehicle, after the brakes have been done. If you look in there, they look nice and shiny. 

2010 Audi S4 Brake Wheel Bearing Replacement

Next picture, the rusted brake rotor. So this shiny part of the rotor here, that should be shiny everywhere from, if you look at my mouse pointer, from that edge to that edge. It should be shiny and smooth with none of these patches here. And these rusty patches here are what caused the brakes to make the noise.

2010 Audi S4 Brake Wheel Bearing Replacement

I have another photo of this view. Again, you can see the rust. There's a sort of interesting patch here, and the owner had said the vehicle had sat for a while. It was probably where the vehicle was stopped and the brake pad was sitting in this area. You can kind of see it's one area that's sort of a little less worn than the others. A little less rusted. 

2010 Audi S4 Brake Wheel Bearing Replacement

So that's the brake. So what repairs did we do? So on the brakes, we actually replaced the pads and rotors. Now a couple of years ago, we did a full, maybe a little over two years ago, we did a full four wheel brake job on this vehicle cuz the brakes were worn out.

So we put new pads and rotors in. And the brake pads still had a fair bit of material and we thought, well, maybe we can salvage the brake pads and just sand them. But they actually, you know, from the rust it, it, it just looked like the brake pads would probably, even though we could sand them down, they might work. They probably squeak and squeal and cause issues. So it just made more sense to change everything and it would've saved a couple of hundred dollars to not change the brake pads, but could have ended up just causing further issues down the road. So it made more sense to just do it all while we were doing the work.

So that's what was involved in the brakes, new pads and rotors. The caliper were all in good shape and the brake fluid was due for a flush based on the time and mileage since we'd last done it. 

Now for the wheel bearings, we basically replaced the wheel bearings. So these are interesting design. So there's a metal wheel, actually, I'll look, show the other picture first. So this is the actual new wheel bearing. It's not fully bolted in yet. The hub remains the same. We transfer the hub from one to the other, but the wheel bearing, it's basically a metal plate with a very large ball bearing assembly.

2010 Audi S4 Brake Wheel Bearing Replacement

Two bearings inside this and the hub press fits onto there. So we pull that on and off of the hydraulic press. But getting this off can be a real pain. This is a steel assembly. This is aluminum. And when these two metals meet especially if, you know, over years of water and road salt, basically the metal corrodes and the bolts that hold these in, they use a very shallow triple square socket at the back, pretty much impossible to remove.

So we actually use a cutting tool and actually cut this piece apart and cut the bolts off and then punch 'em out with an air chisel to get rid of 'em. So it's kind of an ordeal. This is the kind of job you do not want to attempt in your backyard if you're watching this video, cuz it's not a lot of fun.

2010 Audi S4 Brake Wheel Bearing Replacement

But if you see where the arrow's pointing, the red arrow, there's a lot of corrosion on this aluminum here. This is the kind of, it's called dissimilar metal corrosion just kind of happens over time. Now, once we bolt this all back together, it's not an issue. But you know, if you gave it another, I dunno, maybe 10 years of similar wear and salty road conditions, this might end up corroding to the point where you'd have to replace it. But probably good for a long time. This is the the end of the drive axle. This big, huge bolt here, which gets replaced as a new bolt is you know, it, it basically holds the axle to the wheel bearing and hub assembly. So I think that's our picture show. 

Mark: So, first question, how do brake rotors rust so badly? 

Bernie: This is basically, I think a lot of it's from road salt. So I talked to the owner of the vehicle, you know, do you drive it on salty roads? Vancouver, we don't use a lot of road salt. It doesn't snow too much, but we did have a big snowfall in early November.

It was right around the time the owner parked the vehicle, so he had been out driving it a bit in the snow. Plus I said, Whistler's a popular area. It's a ski resort nearby. There's a lot of road salt used on that road. He said, yes, I go up there from time to time. So stuff like that, anywhere where you drive in some winter conditions and there's road salt that can cause these rotors to, you know, it can cause a sort of foundation of rusting.

Now what possibly happened is he may have been out driving it when we had the snowfall and just parked the vehicle and that salty water just sat there and percolated on the metal. If that's the right word, went to work and started eating the metal. 

Mark: So is there anything that someone can do to prevent that kind of rusting of the rotors?

Bernie: Well, flushing it with fresh water every once in a while would probably be a good thing. I mean, sometimes you don't really anticipate these things and think about them, but if you do drive in an area with a lot of road salt, actually washing them off from time to time would be a good thing to do.

You know, for the owner of this vehicle, what may have been helpful, we don't really know what the rotors would've looked like before he parked, but maybe going out for a bit of a drive, washing them off with some water and then parking the vehicle may have actually prevented this issue from occurring.

But again, we don't know you know, getting the back of the rotors a little difficult. So it might just be that there was nothing much that could be done. And we don't normally see these kind of rotors unless they're vehicles that are driven in really salty climates. But to have a thump like that was really something that probably happened from the vehicle just sitting in it. And I'd say just some unfortunate circumstances. 

Mark: And how are 2010 Audi S4s for reliability? 

Bernie: They're pretty good cars. I mean, they are pretty complex. You know, we're talking about a brake job here that probably could have been prevented if the vehicle was driving in a different climate or different conditions. So these brakes would've lasted quite a lot longer. And the vehicle's a standard too. So brakes last quite a long time on these things. But generally they're a fairly reliable car, but they're complex. And so a lot of things do tend to go wrong and they're German, so just expect that there'll be more things to go wrong than than a Toyota. That's our Toyota benchmark. I don't know, maybe we'll make Tesla's the benchmark or something, or some kind of EV the benchmark, in the future. 

Mark: If you're looking for service for your Audi, the guys to see in Vancouver are Pawlik Automotive. You can book online on their website, Or you can call them (604) 327-7112 to book your appointment. You have to book ahead. They're always busy. Pawlik Automotive in Vancouver, BC Canada. Thanks so much for watching and listening. We appreciate it. Thanks, Bernie.

Bernie: And thank you, Mark, and thanks for watching.

About the author 

Bernie Pawlik

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