[Tgawe]

I have a slight vibration that is felt through the entire car when braking downhill at highway speeds. The vibration doesn't affect the steering wheel and doesn't necessarily feel like it's coming through the braking pedal but rather feels like the whole car is 'slightly' vibrating with a rumbling(ish) sound.

I took my car to the dealership and they said nothing was wrong although I have reason to believe they didn't actually do much investigation. They said they took it for a test drive around the local area but after reviewing the dashcam footage (that I'm guessing they didn't notice I have installed) they simply went down the road, braked slightly fast, and the turned around and went back to the dealership.

 

[xydadx3]

Sounds like your dealership hired the same people my ex-dealership has. Take a look at your front rotors. If they have stripes like this they’ll need replaced.

If you do a search of the site for brakes you should find a few other threads which may help

 

[Robert.Mauro]

Sounds like your dealership hired the same people my ex-dealership has. Take a look at your front rotors. If they have stripes like this they’ll need replaced.
View attachment 3161

If you do a search of the site for brakes you should find a few other threads which may help

They can be resurfaced. But, what I'd want are the new pads. The front pads have a new revision.

 

[xydadx3]

They can be resurfaced. But, what I'd want are the new pads. The front pads have a new revision.

Whether or not they can be resurfaced depends if they are warped or just grinding. It’s hard to tell exactly what symptoms the op has. If they’re warped then resurfacing them won’t help after they come up to temperature.
Is there a new part number on the front pads? I’m disassembling mine tomorrow (depending on rain) so I’m curious about that and whether or not there’s any lube on there (I’m doubting there is).

 

[BroDoze]

Mine has had heavy vibration since new. Need to get it in! No time! Sick of the dealer!

 

[Robert.Mauro]

Whether or not they can be resurfaced depends if they are warped or just grinding. It’s hard to tell exactly what symptoms the op has. If they’re warped then resurfacing them won’t help after they come up to temperature.
Is there a new part number on the front pads? I’m disassembling mine tomorrow (depending on rain) so I’m curious about that and whether or not there’s any lube on there (I’m doubting there is).

None i am aware of, to date, have actually been warped. For instance, the photo above is of pulse glazed rotors.

I'd be very interested in finding actually warped rotors instead of ones where the glazing was misdiagnosed as warping. I'm keeping an eye out for them, though. Not doubting they exist, just haven't seen any yet.

 

[xydadx3]

I suppose I’d have to get measurements from those rotors to say for certain. I don’t have them anymore so it’ll forever be a mystery.
What would cause“pulse glazing”? I can see how resurfacing rotors would fix glazing issues; however, resurfacing 3x didn’t fix anything. But, both the pads and rotors were changed so there were too many variables to narrow it down.

 

[Robert.Mauro]

I suppose I’d have to get measurements from those rotors to say for certain. I don’t have them anymore so it’ll forever be a mystery.
What would cause“pulse glazing”? I can see how resurfacing rotors would fix glazing issues; however, resurfacing 3x didn’t fix anything. But, both the pads and rotors were changed so there were too many variables to narrow it down.

I'm still trying to figure out the solutions, but, there's new front pads, so, maybe that's it. Also, in other models, there's the lube and install instructions which are supposed to help break-in and prevent such issues.

One thing that's been consistent in almost all cases, is the residue pattern. I'm on my original pads (though not for much longer, since I've abused them for over 50,000 miles) and original-but-turned rotors. Slight pulsing sometimes, but no longer the big shuddering braking of before I had the rotors turned. I did take better care to break them in, and they did follow the other-model lube instructions when they reinstalled my pads.

So, I'm kinda at a loss on this one too...

 

[ratbag]

I wonder if you might have a wheel bearing issue. I had this same problem on my impreza. The front brakes would shudder sometimes and feel as if they were out of round then they would be perfectly normal for long periods. It was an intermittent problem. Once the wheel bearing was replaced the brakes were perfect all the time.

 

[xydadx3]

I wonder if you might have a wheel bearing issue. I had this same problem on my impreza. The front brakes would shudder sometimes and feel as if they were out of round then they would be perfectly normal for long periods. It was an intermittent problem. Once the wheel bearing was replaced the brakes were perfect all the time.

Might be able to check for that by jacking a wheel off the ground and gripping the wheel with both hands 180° apart. Jerk it back and forth and check for any play.

 

[Tgawe]

I've scheduled another appointment to have them take a longer look at it. I'll let you guys know about any updates and if they track down the cause.

 

[Robert.Mauro]

Might be able to check for that by jacking a wheel off the ground and gripping the wheel with both hands 180° apart. Jerk it back and forth and check for any play.

There will always be rotational play.

Anyways, front Subie bearings sound horrid under normal driving no braking. Hard to miss the sound.

 

[xydadx3]

There will always be rotational play.

Here’s an illustration of the movement I meant to look for. Everything should be snug (honestly not sure which figure is most applicable to the ascent but the idea is the same)

 

[ratbag]

Won't agree with you on this... my subie made no sounds at all... just looseness, wandering and sometimes front brakes that felt out of round. Every other FWD car I've owned made huge noises when frt bearing began to fail. Not my Impreza. In fact the dealer replaced both front bearings when the car had only 5000 Kilometers on it. I mentioned this in another post.

There will always be rotational play.

Anyways, front Subie bearings sound horrid under normal driving no braking. Hard to miss the sound.

 

[Tgawe]

The dealership replaced both my front rotors and everything seems to be good now. Braking is much smoother. According to the service description the rotors were found to be warped.

I just hope they don't end up warped again in the future ?

 

[MrTire]

I have the similar problem. I will apply your solution. So i am looking forward your application

 

[subarumom]

I took mine to the dealer which said they couldn't replicate a similar vibration due to excessive speeds. (75 coming off highway, braking to 45 on ramp). I have excessive shaking, so much so that I actually find myself pumping the brake because I feel like it's going to give out on me. Pumping the brake, on a dry road, for fear that my brakes will give out with only 20k on the car. Something isn't right. I've contacted Subaru of American and will likely have to take the car to another dealer close to the highway that can replicate. I'm seriously concerned for my safety and that of my kids. Thoughts?

 

[Robert.Mauro]

I took mine to the dealer which said they couldn't replicate a similar vibration due to excessive speeds. (75 coming off highway, braking to 45 on ramp). I have excessive shaking, so much so that I actually find myself pumping the brake because I feel like it's going to give out on me. Pumping the brake, on a dry road, for fear that my brakes will give out with only 20k on the car. Something isn't right. I've contacted Subaru of American and will likely have to take the car to another dealer close to the highway that can replicate. I'm seriously concerned for my safety and that of my kids. Thoughts?

It's not a danger, if you are describing what dozens of others here have. It's just an annoyance.

Hoping that the new dealer can get it fixed for you.

 

[xydadx3]

@subarumom I agree with @Robert.Mauro that its more of an annoyance than a safety problem. With that said, it is VERY annoying especially on a fairly new vehicle. I had to take a tech with me on a test drive and warn him that i'm about to brake from 70-20mph in a short distance on an off ramp. After that my front rotors and pads were quickly replaced. Best of luck to you. Don't worry, you'll be enjoying smooth brakes again soon!

 

[BroDoze]

I have the same issue. Have NOT had time to get in in the shop. Last thing I have time for right now. Ugh.