Rocks in the rotors

[Meteor]

More often than not, I'll pick up a rock when off-road that gets lodged somewhere in the brake system, which causes a high-pitched squeal. At least I think that's what it is. I don't hear it at low speeds, so standing next to it while someone else drives doesn't help to pinpoint the sound. It's always on the driver's side, though.

I'll try driving in reverse at a higher than normal speed to dislodge it, but that doesn't work. The sound comes and goes depending on the turn angle the truck is in as well. Eventually, it works its way out, whatever it is, and the squeal stops. It also occurred to me that this might be related to the brake squeal in reverse TSB in some way, but who knows.

It sucks because it becomes so annoying that I'll have to keep the windows up and that's no fun! I've never experienced this in my 4Runner, and it consistently happens in the LC, so it has me wondering. Has anyone else experienced this?

 

[ultane]

Not yet…

 

[D-mac]

I've also found that the brakes squeal a little when cold and then get quiet when the pads get nice and hot. Typical behavior for semi-metallic brake pads. Some fresh brake pads of a different compound (ceramic?) may take care of the issue.

 

[Meteor]

I've also found that the brakes squeal a little when cold and then get quiet when the pads get nice and hot. Typical behavior for semi-metallic brake pads. Some fresh brake pads of a different compound (ceramic?) may take care of the issue.

Usually by the time I've reached the dirt, I've been driving a while so nothing is cold. Would this occcur when the no brake pressure is being applied?

 

[omgponies]

It has been more than 10 years since I last had a car with ceramic brakes - but back then, ceramic would have been worse for the squeaking issue and "work better when warm" is instead "only work when warm" so that means for normal driving they are crap. So you tend to see them on track cars and then (stupidily) on sports cars that aren't necessarily ever on track - but as a result, are driving around with terrible brakes for normal day to day use.

Maybe in the last 10 years the tech has changed dramatically so it is no longer the case, no clue - haven't stayed current.

 

[D-mac]

It has been more than 10 years since I last had a car with ceramic brakes - but back then, ceramic would have been worse for the squeaking issue and "work better when warm" is instead "only work when warm" so that means for normal driving they are crap. S

I've had several cars with aftermarket ceramic pads (Akebono) and they have been the opposite- great for daily drivers with low dust and smooth/quiet around town, and competent but not great for high temperature or performance applications that semi-metallic pads are made for. The old school organic pads are cheap and quiet too, but don't perform as well as the others.

 

[NoMe cruiser]

More often than not, I'll pick up a rock when off-road that gets lodged somewhere in the brake system, which causes a high-pitched squeal. At least I think that's what it is. I don't hear it at low speeds, so standing next to it while someone else drives doesn't help to pinpoint the sound. It's always on the driver's side, though.

I'll try driving in reverse at a higher than normal speed to dislodge it, but that doesn't work. The sound comes and goes depending on the turn angle the truck is in as well. Eventually, it works its way out, whatever it is, and the squeal stops. It also occurred to me that this might be related to the brake squeal in reverse TSB in some way, but who knows.

It sucks because it becomes so annoying that I'll have to keep the windows up and that's no fun! I've never experienced this in my 4Runner, and it consistently happens in the LC, so it has me wondering. Has anyone else experienced this?

What diameter rim are you running?

 

[omgponies]

I've had several cars with aftermarket ceramic pads (Akebono) and they have been the opposite- great for daily drivers with low dust and smooth/quiet around town, and competent but not great for high temperature or performance applications that semi-metallic pads are made for. The old school organic pads are cheap and quiet too, but don't perform as well as the others.

this is great to hear - I need to look into it -like I said, sounds like I am out of touch

 

[Meteor]

What diameter rim are you running?

Stock 18".

 

[NoMe cruiser]

Stock 18".

The paint on the inside of my OEM 18’s has rubbed off from gravel, ice etc. there’s not much clearance there. It’s worse in the front, that’s where I noticed it when I rotated tires. I get some noise after going through mud, especially if I get really mired but all my 4x4 have done that. I’m not saying that is your issue, just thought I’d throw that out. I couldn’t see putting 17” rims on these lc’s.

 

[Meteor]

I was trying to find a section from my last trip where the camera picked up the squeal, but no luck. However, there is another sound, like a high-pitched rub, that it did pick up (and I've heard from inside while driving off-road prevoulsly) that may be related.

Link to a section where it can be heard:

 

[Bad1975]

The video sounds like suspension noise from bushings or possibly the shocks, do you have OME installed?

Have you found any of the rocks, if so where are they getting lodged? Maybe you have a bent brake backing plate that is allowing gravel to stuck up in there? I'd wouldn't drive far with gravel on the rotors as it will leave a groove pretty quickly if you're hearing squealing.

 

[Meteor]

The video sounds like suspension noise from bushings or possibly the shocks, do you have OME installed?

Have you found any of the rocks, if so where are they getting lodged? Maybe you have a bent brake backing plate that is allowing gravel to stuck up in there? I'd wouldn't drive far with gravel on the rotors as it will leave a groove pretty quickly if you're hearing squealing.

Yep, everything is stock. It's been like that for a bit, and I'll have it looked at during the next service.

I've never found a rock. If it were a rock against the rotor, I would see (and the service tech would mention) damage. But so far it looks fine. What else might cause a squeal to occur while off-road only and then carry on when I'm back on-road for a short while? It's odd.

 

[Bad1975]

Kinda hard to see a rock between the backing plate and backside of the rotor. Could be allot of dust I guess maybe if you haven't had the brake recall done, but not very likely.

 

[wpage]

Any scoring on the rotors?
Could be something lodged in there. May leave a line....

 

[ultane]

@Meteor, any new developments?

 

[Meteor]

Any scoring on the rotors?
Could be something lodged in there. May leave a line....

@Meteor, any new developments?

Sorry, I went MIA.

Not yet. I'm going to wait for the next service and ask them to look at it closely and bring up all your suggestions. I’ll report back.

My gut says it's a build-up of dust on something rotational because the sound continues when back on-road but only for a short while, as if the dust clears off. The sound is not continuous either, like I’d expect if a rock got into the rotor. The squeal comes and goes with how the suspension is being loaded at that moment, which is also odd. And I’ve never had a report of rotor damage during service after this has happened (and it always happens when off-road with the exact same symptoms).

It can be embarrassing when rolling by people. It’s almost like the TSB backup squeal but not as loud.