FAQ: Vibration under braking: warped rotors? NO!

[StingertimeNC]

I have the stock rotors and calipers and just switched to Hawk Street pads in the front only. My car had maybe 2k mikes when I did this. 3k miles later and it’s fine. I always let my brakes cool down a bit if I’m being hard on them by driving around a few minutes nice and easy. Hawk pads are a bit noisy when the brakes are cold but that doesn’t bother me. I did do the brake bedding process when I put the pads on. If you switch pads, just have your rotors turned when you put the new pads in.

 

[WRXtoStingerGT]

I have the stock rotors and calipers and just switched to Hawk Street pads in the front only. My car had maybe 2k mikes when I did this. 3k miles later and it’s fine. I always let my brakes cool down a bit if I’m being hard on them by driving around a few minutes nice and easy. Hawk pads are a bit noisy when the brakes are cold but that doesn’t bother me. I did do the brake bedding process when I put the pads on. If you switch pads, just have your rotors turned when you put the new pads in.

^ smart

 

[KNSBrakes]

Hawk has 3 street pads, HPS, HPS 5.0 and Perf. Ceramic. Which one?

PS

Pic from customer.

Are these the Euro pads? That 'GG' in the middle is a 'friction code' GG is pretty aggressive, (Hawk 5.0's are usually 'FF' and ceramic pads are usually 'EE')

And of course you can see the weights and wrap around shims that 'normal' pads in D1001 don't have.

 

[StingertimeNC]

HAWK 5.0 Brake Pads Kia Stinger Brembo

www.khartunerz.com

this is what I bought.

 

[SpaceGhost]

HAWK 5.0 Brake Pads Kia Stinger Brembo

www.khartunerz.com

this is what I bought.

What about rotors?

 

[StingertimeNC]

What about rotors?

kept the stock rotors. I changed mine with only 2k miles on the car. Did a nice bed in process, etc. I had no pulsating, and haven't had any since. Like I said, I baby the brakes a bit though, let them cool off and if I get stuck at a stop light and I've been beating on the car a bit, I will apply the parking brake so I can let off the brake pedal. Take every precaution. I'm heading to VIR (track) in November, so we will see how they hold up.

 

[CeramicGT001]

kept the stock rotors. I changed mine with only 2k miles on the car. Did a nice bed in process, etc. I had no pulsating, and haven't had any since. Like I said, I baby the brakes a bit though, let them cool off and if I get stuck at a stop light and I've been beating on the car a bit, I will apply the parking brake so I can let off the brake pedal. Take every precaution. I'm heading to VIR (track) in November, so we will see how they hold up.

Yea I did the same exact thing a couple months ago but I had 27k miles on the rotors. Braking overall is smoother but I still get some pulsing here and there. Also the the left side brake has a high pitched squeal when braking lightly around 50mph. I’ve taken it out and regreased the pads but still makes the noise occasionally. I’ll likely go with drilled/slotted rotors and new rear pads too soon.

 

[SpaceGhost]

Just out of curiosity what is the torque spec on the caliper bolts?

 

[SoCalSHO]

Tightening torque​

Tightening Torques

Items​	N·m​	kgf·m​	lb·ft​
Master cylinder to brake booster nut​	12.7 - 16.7​	1.3 - 1.7​	9.4 - 12.3​
Master cylinder flare nut​	18.6 - 22.5​	1.9 - 2.3​	13.7 - 16.6​
Brake booster mounting nuts​	16.7 -22.5​	1.7 - 2.3​	12.3 - 16.6​
Front caliper guide rod bolts (17 in only)​	21.6 - 31.4​	2.2 - 3.2​	15.9 - 23.1​
Rear caliper guide rod bolts (17 in only)​	21.6 - 31.4​	2.2 - 3.2​	15.9 - 23.1​
Air bleeding screw​	17 in​	6.9 - 12.7​	0.7 - 1.3​	5.1 - 9.4​
18 in​	16.7 - 19.6​	1.7 - 2.0​	12.3 - 14.5​
Front caliper assembly to knuckle​	Standard​	78.5 - 98.1​	8.0 - 10.0​	57.9 - 72.3​
Brembo​	98.1 - 117.6​	10.0 - 12.0​	72.3 - 86.8​
Rear caliper assembly to knuckle​	Standard​	78.5 - 98.1​	8.0 - 10.0​	57.9 - 72.3​
Brembo​	98.1 - 117.6​	10.0 - 12.0​	72.3 - 86.8​
Brake hose to caliper​	24.5 - 29.4​	2.5 - 3.0​	18.1 - 21.7​
Brake pedal member bracket bolts​	16.7 - 25.5​	1.7 - 2.6​	12.3 - 18.8​
Brake disc screw​	4.9 - 5.9​	0.5 - 0.6​	3.6 - 4.3​

 

[SoCalSHO]

Torque specs should be here. It is also a link to the service manual.

http://www.kstinger.com/front_disc_brake-609.html

 

[SpaceGhost]

Tightening torque​

Tightening Torques

Items​	N·m​	kgf·m​	lb·ft​
Master cylinder to brake booster nut​	12.7 - 16.7​	1.3 - 1.7​	9.4 - 12.3​
Master cylinder flare nut​	18.6 - 22.5​	1.9 - 2.3​	13.7 - 16.6​
Brake booster mounting nuts​	16.7 -22.5​	1.7 - 2.3​	12.3 - 16.6​
Front caliper guide rod bolts (17 in only)​	21.6 - 31.4​	2.2 - 3.2​	15.9 - 23.1​
Rear caliper guide rod bolts (17 in only)​	21.6 - 31.4​	2.2 - 3.2​	15.9 - 23.1​
Air bleeding screw​	17 in​	6.9 - 12.7​	0.7 - 1.3​	5.1 - 9.4​
18 in​	16.7 - 19.6​	1.7 - 2.0​	12.3 - 14.5​
Front caliper assembly to knuckle​	Standard​	78.5 - 98.1​	8.0 - 10.0​	57.9 - 72.3​
Brembo​	98.1 - 117.6​	10.0 - 12.0​	72.3 - 86.8​
Rear caliper assembly to knuckle​	Standard​	78.5 - 98.1​	8.0 - 10.0​	57.9 - 72.3​
Brembo​	98.1 - 117.6​	10.0 - 12.0​	72.3 - 86.8​
Brake hose to caliper​	24.5 - 29.4​	2.5 - 3.0​	18.1 - 21.7​
Brake pedal member bracket bolts​	16.7 - 25.5​	1.7 - 2.6​	12.3 - 18.8​
Brake disc screw​	4.9 - 5.9​	0.5 - 0.6​	3.6 - 4.3​

So I had this local mechanic change my brakes. They were starting to shudder again so I bought parts and tried to do this myself. I have an impact wrench that does 330lbs and the f'ing bolts on the caliper would not come off. I took a breaker bar with an extra piece of pipe it would not budge. I guess I'll have to get a better impact wrench because at some point I'll need to get it off.

The rotors the mechanic put on the car were stock Kia. They only have couple of thousand miles on them. He used a different pad because the Kia pads were $500. Anyway I just changed the pads to Hawk HPS 5 and it seems fine. I drove it on the highway and it wasn't shuddering.

Although the real test is driving in traffic where you are going 80 then 30 then 50 then stop then 30 stop etc. That's when it would start. Which is why I am not going for the pad deposit story. At least not on my car. It's definitely heat related. Hopefully these hawk pads make less heat.

My wife has the same car so I guess I can use the rotors on her car.

 

[SpaceGhost]

BTW if you are considering the Hawk pads they are not listed for our cars. It says they are for a Subaru STI/Mitsubishi Evo, but they fit perfectly. The item number is HAWHB453B.585. I paid 165 on khartunerz site, but they can be had on Amazon for 119

https://www.amazon.com/Hawk-Performance-HB453B-585-Disc-Brake/dp/B00KMUEFIQ

 

[NS_Stinger]

I just wanted to follow-up and say that I've been running my Girodisc magic pads for something like 2 years now and the vibrating up front has not returned. What I will say is that I've started to hate these pads because they squeal ALL THE TIME. I'm considering dropping them for a less aggressive ceramic pad with the weights on it since I think the lack of weights on the Girodisc pads might be part of the squealing issue along with them being semi-metallic pads.

 

[BadTrainDriver]

Although the real test is driving in traffic where you are going 80 then 30 then 50 then stop then 30 stop etc. That's when it would start. Which is why I am not going for the pad deposit story. At least not on my car. It's definitely heat related. Hopefully these hawk pads make less heat.

Brakes work by friction (heat). The brake pad leaves a microscopic layer pad material on the face of the brake rotor during braking, and it is constantly being replaced. The more aggressive the brake pad, think semi metallic, the better the the continual transfer of pad material on the rotor. With ceramic pads, you have more of a potential issue with the pad not sweeping the face of the rotor evenly. Basically, it smears the pad material on the face of the rotor. That smear, or uneven pad deposit, is what causes brake pulsation. It happens more when the brakes are hot, again, not sweeping the face of the rotor clean, think smearing. My OEM ceramic pad caused pulsation at speed after a few aggressive drives. When I switched to the "euro" semi metallic pad, all I did was replace the pads and bed the brakes. The pulsation went away and has never returned. The downside is a semi metallic pad does dust more, and has more potential to make noise at low speeds(squeal).

 

[SpaceGhost]

Brakes work by friction (heat). The brake pad leaves a microscopic layer pad material on the face of the brake rotor during braking, and it is constantly being replaced. The more aggressive the brake pad, think semi metallic, the better the the continual transfer of pad material on the rotor. With ceramic pads, you have more of a potential issue with the pad not sweeping the face of the rotor evenly. Basically, it smears the pad material on the face of the rotor. That smear, or uneven pad deposit, is what causes brake pulsation. It happens more when the brakes are hot, again, not sweeping the face of the rotor clean, think smearing. My OEM ceramic pad caused pulsation at speed after a few aggressive drives. When I switched to the "euro" semi metallic pad, all I did was replace the pads and bed the brakes. The pulsation went away and has never returned. The downside is a semi metallic pad does dust more, and has more potential to make noise at low speeds(squeal).

Thanks the hawk pads are semi metallic so hopefully I'm all set. If so I'll save the rotors for my wife's car. Hers doesn't have the brake issue and has about 25K miles so I'm thinking probably another 10-15K she'll need brakes and I'll use the rotors on her car.

 

[SpaceGhost]

So changing the pads alone did not work. Once the brakes heated up they started shuddering again. I bought a better impact wrench last night and installed the new rotors today. So I have new CENTRIC PREMIUM ROTOR and Hawk HPS 5.0 pads. Fingers crossed

 

[RogueIV]

So changing the pads alone did not work. Once the brakes heated up they started shuddering again. I bought a better impact wrench last night and installed the new rotors today. So I have new CENTRIC PREMIUM ROTOR and Hawk HPS 5.0 pads. Fingers crossed

Did you do the bed in process for the pads? It's essential that you do. Brake Installation & Bed In Tutorials | Hawk Performance

 

[SpaceGhost]

Did you do the bed in process for the pads? It's essential that you do. Brake Installation & Bed In Tutorials | Hawk Performance

I did exactly what it said on the box, but also feel people are making too big of a deal out of this. Not bedding the brakes exactly right isn't going to make the brakes shudder. I had a GTI, a Mini, G35 coupe never a problem with brakes and I never bedded anything. I'll tell you I see brembo brakes in the future thanks but no thanks

 

[RogueIV]

I did exactly what it said on the box, but also feel people are making too big of a deal out of this. Not bedding the brakes exactly right isn't going to make the brakes shudder. I had a GTI, a Mini, G35 coupe never a problem with brakes and I never bedded anything. I'll tell you I see brembo brakes in the future thanks but no thanks

No, but if you're doing brakes on used rotors it's not going to clear out the old deposits and it will shudder if it was shuddering in the past.

 

[RM7]

I did exactly what it said on the box, but also feel people are making too big of a deal out of this. Not bedding the brakes exactly right isn't going to make the brakes shudder. I had a GTI, a Mini, G35 coupe never a problem with brakes and I never bedded anything. I'll tell you I see brembo brakes in the future thanks but no thanks

Yeah, you have to take a few steps back to just see how ridiculous the claims are. Like, are you going to install your brake pads on the side of the freeway? Because that's literally the only way you will be able to brake like this from the beginning, assuming it's not very crowded. Most brake bedding in procedures are due to lack of power, until fully bedded in. That's why there are warnings that you may not have full power/ability to stop. Especially true for certain compounds. But these cars (and all others) are made at the factory, test driven short distances, loaded, driven to dealers, test driven some more, bought, stopped and started many times usually before getting on the highway. If this was so critical, it would be happening on every car ever made, all the time. The reason it's happening here is because the brake frequency is screwed up, allowing small vibrations to propagate into rotor wobble. If you could stick a go-pro in there while this is happening you'd likely see the rotor or pads blur, while they vibrate back and forth real fast. I too have changed pads on cars multiple times. This just doesn't happen, unless something is screwed up. It's not to say you can't have a pad shedding material due to a production flaw in the material, that does happen, but it's ultra rare.