What is this weird sound

[oakback]

I've had it for months, but it happens randomly, I'm glad to finally catch it on video. It's happened when hot, cold, braking, accelerating, turning, going straight, sitting still, bumps, smooth, and I can't do anything to intentionally make it happen. It sounds like it's coming from the front/left area. It's never longer than what's heard in the video. Sometimes it won't do it all day, other times it'll do it 5 times in a 20 minute commute. I don't see anything odd on a visual inspection.
Ignore the tapping sounds, that's me setting stuff down. It's only the screech sound that I'm worried about.

 

[FamilyCamper]

seems like it also jerked the vehicle. Any lights on the dash for vsc or trac control? Maybe wheel bearing issue? I would check for 12 and 6 play in that wheel at a minimum.

 

[Import Driver]

That is a sound I have never heard a car make.

 

[oakback]

seems like it also jerked the vehicle. Any lights on the dash for vsc or trac control? Maybe wheel bearing issue? I would check for 12 and 6 play in that wheel at a minimum.

The jerking is probably the crappy pavement, the noise doesn't coincide with any steering wheel feeling. No lights for vsc or trac control.

If it's a bearing issue, could it happen while sitting still?

 

[FamilyCamper]

The jerking is probably the crappy pavement, the noise doesn't coincide with any steering wheel feeling. No lights for vsc or trac control.

If it's a bearing issue, could it happen while sitting still?

if it happens while sitting still the no and I would look to engine accessories for the noise.

 

[SHIfTHEAD]

Beginning of this?

 

[2001LC]

The sound seems as if in the cabin. Make sure cabin fan(s) off, and sound still present.
There's a sound, very similar, that comes from under the hood. It's comes from brake master, as brake fluid, passes a seal under high pressure.

 

[oakback]

That sounds exactly like it at 0:04 in the video. Is it something to worry about? Should fluid be passing that seal, or is that indicative of failure?

 

[2001LC]

Yes, it is a concern!

If, the brake master is losing pressure passed seals, is the sound. You'll see bubbles come up front of reservoir, as sound heard. If so I'd then bet, your reservoir is stained. It's the not taking care of the Toyota brake fluid, that causes seals to go bad.

It will continue to get worst (longer duration and more frequent). It is the longer duration, most worrisome. Because as the pressure (sound of fluid passing seal under high pressure) drops, booster motor runs to bring pressure back up. Longer duration, results in premature brake booster motor failure.

Poll on total brake failure in 100 series

There is some discussion going on of total and sudden braking failure in 100 series models, with reports of no -or essentially no- braking left at all a very short time (of the order of seconds/minutes) after dashboard warnings. That is scary stuff. It is, however, also difficult to find out...

forum.ih8mud.com

Cure: New brake master w/booster assembly.

Brakes ...... Overdue write-up.

First and foremost: Brakes should only be worked by those, with high level of mechanical abilities and experienced with brake systems. With the age of all 100 series today, in our aging fleet. Any issue, with brake master assembly. IMHO, best and safest course of action. Have the whole brake...

forum.ih8mud.com

 

[oakback]

Thanks for clarifying, I'll get on that.

 

[oakback]

I rebuilt the master cylinder with the recommended Toyota kit. I bled the brakes, and the initial test drive to give the abs a workout felt great. I'm going to bleed it again, but figured I'd post now, it started screeching again almost immediately.

I followed the write-ups for the rebuild, and didn't encounter any problems, everything went smoothly. The cylinder bore looked pristine, and I was careful to lube the new one and keep it centered to keep from scratching the walls.

I'll do more searching on here, but grateful for any feedback.

 

[oakback]

Would failing internal seals in the master make the noise as well? In this post (#13), @2001LC you mention that these aren't sold by Toyota.

 

[2001LC]

Would failing internal seals in the master make the noise as well? In this post (#13), @2001LC you mention that these aren't sold by Toyota.

In post #1 there's a video. You'll hear the sound, very briefly, of fluid passing a failing non replaceable seal.

 

[oakback]

Well s***, I read stuff wrong and rebuilt the MC when I should have replaced it. My bad, wasted a weekend. Anybody want to buy a barely-used MC rebuild kit? haha

 

[2001LC]

Seen that before.

It why (most) Dealership Tech and even Master, don't even know there's a master kit. They do one thing only, replace the whole deal. Safer, save time (labor), cost less in long run and customer is happy not needed to come back.

Warning. These so called rebuilt master, are a waste of money and time IMHO. What your seeing, happens to most of them within 2 to 3 years, of average use..

 

[oakback]

I dropped the coin for the new master cylinder, and took my time swapping over the booster components. Installed everything, no problems along the way, it went smooth. I didn't remove the inner cylinder, I left it as it was from the box, nothing looked wrong. I bled the brakes thoroughly, exercised the ABS a lot, and bled again. No leaks from anywhere that I can see, no warning lights or beeps.

I'm still getting the screech, although it's shorter now, more like a rapid chirp. Improves as it warms up. It's very frustrating. Braking performance feels fine, so I've got that going for me, which is nice. What's left to try here?

 

[2001LC]

Why did you only replace just the brake Master, and not the whole deal (booster w/brake master ASSY)?

Perhaps, the sound came from elsewhere:

I suggest you: Post a video of whole Brake Master ASSY in the video. Focused on the front of reservoir. It must be, while it is making the sound?

Also post some picture of old brake master reservoir.

Remember, as I explained in video above and elsewhere. We'll see bubbles/ripples in the front of reservoir coinciding with sound. The bubbles/ripples, is believed to be in 98 out of 100 cases. The fluid passing a seal, back into reservoir. The sound, fluid passing the seal under pressure. We see and hear both, not just one or the other. "Both", to make the call, when grading a brake master!

The likelihood of a new OEM Booster w/brake Master ASSY, using Toyota Brake Fluid (only). Failing out of the box. Is highly unlikely, but not impossible.
______________________________________________________________________________

I'll say this for those the come to this thread later, looking for help with sound:

If sound coincides with bubbles/ripples in reservoir or most any issue with an old brake master. Replace the whole brake master ASSY (AKA: BOOSTER w/ MASTER ASSY) the whole deal. Saves time money and is safer.

~3 years ago, Toyota lowered the price of the whole deal (booster w/Master ASSY). If you look at price of the two main components. Booster ASSY & Master ASSY. sold separately. You'll find, it much more costly to buy them separately. It's the old saying: " penny wise dollar foolish". As for only few dollars more, you get it all and save time. Time it take to disassemble and reassemble. The R&R of the whole deal at once, is faster and a one time deal for most each 25 or more years.

Before about 3 yrs ago. We couldn't even get the 98-99 or earlier 00 brake Master. For about 2 years Toyota/Lexus was out.. (except a few rathold in inventor) Only the booster ASSY was available which works on all year 98-07. They may one day run out again.