Moaning + pedal pulsating while turning

can’t return the crap rotors I bought but they’ll exchange them so I’ll give that a try. Thank you

 

The MC looks like the unicorn that is hated.

 

Here's what the mutant ones look like

 

Could it be a wheel speed sensor?

To me that video really sounds like ABS kicking in but at that slow speed there is no reason it should be. My 4Runner brakes sometimes do a groaning pulsing on wide turns at speed like an exit ramp. If I'm fast enough that it's trying to drag the inside front tire a bit it sometimes fully engages abs which is a louder pump sound like the video. Never seen it at low speed. Did it on both original factory brakes and new aftermarket pads.

 

Ah, I forgot you added a video. Yes, that sound at the end sounds like ABS kicking in.

Does the pulsation happen if you slowly apply the parking brake under the same conditions/situation? If not, it's not your drums that are at fault.

Moaning (and even pulsation) can be a sign of air in the brake lines also. Sputtering happens in that case. And air trapped in the brake lines happens a lot on 1st gens because people don't know about/don't bleed the LSPV (load sensing prop valve) that many of our trucks have mounted to the frame, driver's side, above the rear axle. If you have it, it typically has a bent-wire arm with rubber boot, and a round pulley looking wheel that attaches just on the back/passenger side of the diff pumpkin. Anyway, there's a bleeder on the LSPV, and that LSPV sits up higher than any other point on the truck after the cab, so its where air likes to go, and gunk can get trapped. If you ever opened the rear lines, or left a bleeder (on it or the wheel cylinders) cracked, you may have air in the lines causing it.

It's just weird, the timing. Unless you had a bleeder open out back when doing your work. I don't remember seeing you say that.

 

PS, what is that yellow flashing light in the dash I'm seeing? Seat belt? I always wear mine, so I dunno where it'd be flashing in the gauge cluster.

 

looks like TPMS

 

I think it’s the sensor. I need to try to clean it. I will attempt that sometime this week/end

 

Never used this bleeder. You’re not saying I should try bleeding my brake lines correct? Or are you saying I need to release that potential air bubble

 

TPSM

 

If you don't find crap built up on the sensor, be sure to look into the hole and ensure the tone ring for ABS is properly aligned (generally, ballpark) with where the tip of the sensor would be sitting while installed. Also, make sure the sensors have o-rings.

TPMs flashing light is a really easy thing to fix. You can either delete the codes using a scanner that supports accessing the TPMS ECU, or just install known-working sensors and program the TPMS ECU with their ID (or clone them). Or if you have the original sensor IDs, you can program to the currently installed sensors. I lived with that light flashing for too long, only to find 3-4 minutes with my OBDLink dongle let me delete the codes and wipe them from existence.

 

If you've never bled at the LSPV, and you know you have an LSPV, you should re-bleed your brakes. LSPV first, then the rear passenger, then the rear driver.

 

Ok I finally got around to checking the ABS sensor on both front sides. Looked clean to me but I wiped them off anyway. I attached photos just in case anyone wanted to see.

I did notice that when I rotated the rotor on the drivers side by the lug bolts, it would get noticeably more difficult on one part vs. another. So I’m hoping this is the problem and I will be able to exchange my DuraCrap rotors this weekend for new ones that hopefully aren’t problematic. Will keep the thread updated.

 

Is there a reader on Amazon I can order that will do this? Just delete the code entirely?

 

Good Q, not sure.

But back to the ABS sensors, did you peer down into the hole to inspect the tone ring and where it's aligned in the hole? Did you check all four sensors or just the front two?

More info on tone ring in case you're not following: https://www.tundras.com/threads/nee...himmy-and-abs-kicking-in.146298/#post-3669245

It looks like those two o-rings are fine, but this is why it was brought up: https://www.tundras.com/threads/slow-speed-abs-activation-fixed.131442/#post-3343273

 

Ah shoot I wish I had known about that before checking them today I’ll check that ASAP

 

Literally mentioned it in reply #41 above.

Did you check to see if you also feel the same shudder if you (at a slow speed) use the parking brake to come to a stop? Maybe just to isolate the shudder to the front only, or to the rear only?

 

OK I’ve checked out the ABS tone ring and based on the threads I’ve looked at they look ok. But someone can correct me if I’m wrong.

 

Looks great

 

I just inspected the rear sensors, and the looked clean but when I looked at the tone ring on passenger rear I found this.
Very dirty, plus the sensor looks replaced. Maybe it’s a cheap knockoff and it’s gone bad. I’m going to replace the rotors under warranty and see if that’s what the issue is after all. Then I will potentially resort to replacing this sensor and/or cleaning the rear tone ring

 

Both alignments look great. Agree, there is a lot of shit in that rear one.

 

Looks like that rear is wet - perhaps has a leaking seal.

 

Ok guys, sorry to make this whole thread boring: Looks like it was the rotors ‍♂️

I replaced them under warranty and I haven’t been able to recreate the problem so I guess that’s that.

I’m hesitant to wash my hands of this proven, because I’m afraid the rotors will wear a bit over time and the problem will reoccur. In that case I would think that means the problem is somewhere else in my brakes that is causing my rotors to wear unevenly.

either way thank you all for your help and suggestions. I will update this thread if anything changes.

 

Totally. Glad it was simple.

BTW I looked at the rear tone ring window again on a larger screen and that’s not dirt or debris, it’s apparently just some tarnish on the tops of the fins.

And yeah. We always warn folks about aftermarket drums and rotors. This happens absurdly often. Hence the first words I wrote in this post: “Whatever you do, don't buy aftermarket rotors. Trust on this. Never buy aftermarket drums or rotors on these trucks. "We've seen some shit..."”

 

I was able to wipe that stuff off with a Q tip so I don’t think it’s tarnishing… but it doesn’t seem to be causing the issue so I’m not gonna worry about it

Yeah I’m going OEM next time for sure. Hopefully this second pair holds up ok for a while at least.

 

if it works, it works. Roll with it.

Just to be sure, you did hit the faces of the rotors with brake cleaner to remove the finish/film off of them when you installed, correct? They typically have something applied to the shiny surface to prevent corrosion. If you don’t remove it, it’ll transfer to your pads and cause stupid symptoms, like the brakes not grabbing cleanly. I totally forgot to ask this prior, and I guess it’s a question we should be asking more often. I typically shoot the braking surface on both sides of my rotors and the inside braking surface of my drums with Brakleen and wipe away with a disposable blue shop cloth (so I know I’m not transferring oil over) before install. Removes any oil or coating to make sure my pads and shoes don’t pick it up.

Properly bedding your pads any time you install new ones, or new rotors really, is important also. There’s a quick and easy cycle to follow.

 

What is the "bedding" you speak of? As it so happens, Faye recently posted an excellent video:

https://www.youtube.com/watch?v=IqKZoVBPpDU&ab_channel=FayeHadley

And while I was looking for this I found a new video (posted just a few hours ago) highlighting rotor warping:

https://www.youtube.com/watch?v=PlFq1loCxsg&ab_channel=FayeHadley

 

Awesome. I hadn't seen this one yet, I don't actively follow her. But it's always nice to hear truth echoed.

I'd have only added, since she mostly covered what can cause "warpage" after install, some stuff is warped before it gets put into the shipping container to come over here. She even covered bad lug torque causing brake issues, which is one @KNABORES brings up, and is something wheel and tire torque impact monkeys.

 

True that, but the same techniques can help to identify a rotor which is "warped" out of the box. I'm sure somewhere there's a video which explains how a seized caliper (a common Toyota problem) can also contribute to these symptoms, and in fact cause the rotor to overheat and thus "warp".

Faye is shilling for PowerStop (not OEM of course), but to be fair I've used their rotors, pads, drums, and shoes for many years on multiple vehicles without problems.

 

The front brakes on my 2000 4.7 Tundra are an enigma.

Since new, after 5-10k easy miles the front end would start wobbling when brakes applied. Toyota resurfaced and replaced rotors/pads multiples times under warranty. Frustrated, I just gave up and lived with it for over 200k miles and I believe two more brake jobs at Toyota. Then... an independent shop replaced both rotors with Dynamic Friction Company rotors, Centric 301 pad set, and one new Centric CTEK passenger side caliber. Brakes have operated smooth and quiet for the last 53k miles.


I don't know if any of this applies to your situation, but I can yell ya genuine Toyota parts were not the cure for my truck's ills.