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?