Shakin' while Brakin'

[dleclerc27]

Helllllo everyone,

I am chasing a fairly significant shaking when braking at speed (35mph+) on my gen2. Here's what I've done to diagnose, with moderate success in relieving the shake:

1.) Visual inspection of rotors and brake pads with friend who is much more mechanically inclined - no evident issues there.
2.) Replaced front brake pads and clips, lubed everything up. Hawk pads. Gave it a rip with mild alleviation of shaking.
3.) Replaced rear brake pads and clips, lubed everything up. Hawk pads to match the front. No real difference.
4.) BrakeKleen'ed everywhere again.
5.) Made sure bedding process was done, followed suggested guildelines to a tee.

It has been almost 1,000 miles since the initial bedding, which I think is sufficient. I understand that the jump-to answer is warped rotors, but given modern rotors it's quite difficult and inspection doesn't lend itself to that as a culprit. I could be wrong, but my understanding is that warped rotors is unlikely. Doesn't appear to be a CV or ball joint issue either, as I don't hear/feel a clunk and the tire passes the manual shake test. I've also bled the brakes pre- and post- change, looks fine there.

If anyone has any ideas, and I'm sure this has been discussed on the forums (but specific details of my status help), I would appreciate it. Thanks very much!

 

[New recaros]

Buy new rotors and end the madness. Rotor grow a bit when hot increasing the warping. I have never any luck turning a warped rotor.

 

[dleclerc27]

Buy new rotors and end the madness. Rotor grow a bit when hot increasing the warping. I have never any luck turning a warped rotor.

Thank you, that's the likely next step, just didn't know if anyone had other thoughts on it as well. I appreciate it!

 

[Gumby]

Helllllo everyone,

I am chasing a fairly significant shaking when braking at speed (35mph+) on my gen2. Here's what I've done to diagnose, with moderate success in relieving the shake:

1.) Visual inspection of rotors and brake pads with friend who is much more mechanically inclined - no evident issues there.
2.) Replaced front brake pads and clips, lubed everything up. Hawk pads. Gave it a rip with mild alleviation of shaking.
3.) Replaced rear brake pads and clips, lubed everything up. Hawk pads to match the front. No real difference.
4.) BrakeKleen'ed everywhere again.
5.) Made sure bedding process was done, followed suggested guildelines to a tee.

It has been almost 1,000 miles since the initial bedding, which I think is sufficient. I understand that the jump-to answer is warped rotors, but given modern rotors it's quite difficult and inspection doesn't lend itself to that as a culprit. I could be wrong, but my understanding is that warped rotors is unlikely. Doesn't appear to be a CV or ball joint issue either, as I don't hear/feel a clunk and the tire passes the manual shake test. I've also bled the brakes pre- and post- change, looks fine there.

If anyone has any ideas, and I'm sure this has been discussed on the forums (but specific details of my status help), I would appreciate it. Thanks very much!

Buy new rotors and end the madness. Rotor grow a bit when hot increasing the warping. I have never any luck turning a warped rotor.

This^^^^^^ The Question why did they warp in the first place? There are a few reasons why rotors warp.
1 lugs not torqued
2 buildup on the wheel
3 rust build up on the rotor mount surface
4 rust buildup on the spindle mounting surface

 

[FordTechOne]

You likely have have rotor runout that developed into thickness variation, which is the pulsation you feel in the pedal under braking. Rotors do not “warp” in the traditional sense people think of.

You’ll want to either have the rotors machined with an on-car brake lathe (OEM or high quality aftermarket rotors only) or replace them. Hub face runout is the most common cause of rotor runout; the hubs need to be resurfaced and should be checked using a dial indicator.

 

[dleclerc27]

This^^^^^^ The Question why did they warp in the first place? There are a few reasons why rotors warp.
1 lugs not torqued
2 buildup on the wheel
3 rust build up on the rotor mount surface
4 rust buildup on the spindle mounting surface

Thanks! I had checked 2-3, but I have not taken a look at the spindle. LIKELY, it's new rotor time. I was just hoping to put that money towards a new bumper, haha. Thank you very much for the sage advice.

 

[Gumby]

Thanks! I had checked 2-3, but I have not taken a look at the spindle. LIKELY, it's new rotor time. I was just hoping to put that money towards a new bumper, haha. Thank you very much for the sage advice.

@FordTechOne is correct as usual. the rotors don't warp in the sense you might think. If worn thin is another issue. They are not going to warp back to shape. (you will need new ones) Make sure all your surface are clean and true. Don't forget the rim also.

 

[dleclerc27]

You likely have have rotor runout that developed into thickness variation, which is the pulsation you feel in the pedal under braking. Rotors do not “warp” in the traditional sense people think of.

You’ll want to either have the rotors machined with an on-car brake lathe (OEM or high quality aftermarket rotors only) or replace them. Hub face runout is the most common cause of rotor runout; the hubs need to be resurfaced and should be checked using a dial indicator.

Thank you! It seems like the solution here is just new rotors - I'm going to go to an upgraded (StopTech, unless someone has a great recommendation otherwise) rotor as opposed to an OEM replacement. Thanks again, appreciate it!

 

[dleclerc27]

@FordTechOne is correct as usual. the rotors don't warp in the sense you might think. If worn thin is another issue. They are not going to warp back to shape. (you will need new ones) Make sure all your surface are clean and true. Don't forget the rim also.

Thanks, I hadn't REALLY check the inside of the rim, but an imbalance there might be the case so I'll have peek anyways.

 

[Gumby]

Thanks, I hadn't REALLY check the inside of the rim, but an imbalance there might be the case so I'll have peek anyways.

Ok....The rotor is held in place with the lug nuts. and is sandwiched between the hub and the wheel. An uneven surface on the wheel, front if the rotor, back of the rotor, or the spinal all being held by the lug nuts. Can cause the rotor to warp, once they are warped there is nothing you can do except replace them. make sure all your surfaces are clean and true.
I didn't want you to think you clean up the back of the wheel and it will go way. LOL that is not the case.