2014 LX 570 brake issues

[Wstclx2001]

New to me 2014 LX 570 57k miles:

Got new pads, rotors and brake fluid. Seems to stop really well in all instances now. Pedal is tiny bit inconsistent from slightly squishy to nice and firm. Symptoms are the brief hissing/squeak when pressing brake pedal but the more troublesome one is when driving for straight long stretches will go to tap break for whatever reason and it will be stuck almost like brake pedal is rusted or something. Tap it with more force but don't have to mash it and it operates normally. Just kinda catches me off guard and is startling.

My findings from least to most concerning:

1. Makes the famous buzzing sound that triggers a lot of people on here

2. Makes that hissing/squeak briefly when depressing brake pedal during normal operation on road

3. When releasing brake pedal, whether it's off, ignition pressed once, pressed twice or engine on, bubbles can be seen in MC fluid resevoir.

Go ahead, tell me i have 4k repair bill in my future lol

 

[bloc]

3. When releasing brake pedal, whether it's off, ignition pressed once, pressed twice or engine on, bubbles can be seen in MC fluid resevoir.

This is really strange to me. Either even more air needs to be worked out or fresh air is getting into the system. I don’t see how, with a gravity-fed reservoir.. possibly a clogged port from it to the MC, or maybe one of the bushings/gaskets that seals it into the MC is failing?

Or I guess, it could be getting drawn in past the seal at the firewall for the shaft connecting the MC to the brake pedal..

 

[Wstclx2001]

This is really strange to me. Either even more air needs to be worked out or fresh air is getting into the system. I don’t see how, with a gravity-fed reservoir.. possibly a clogged port from it to the MC, or maybe one of the bushings/gaskets that seals it into the MC is failing?

Or I guess, it could be getting drawn in past the seal at the firewall for the shaft connecting the MC to the brake pedal..

Thanks for the quick reply with tons of ideas! Brake fluid was dirty as hell with moisture in there. Florida owned truck. Excellent condition overall but poor preventative maintenance methinks. Am i being naive thinking most of these don't require total MC replacement?!

 

[Wstclx2001]

Thanks for the quick reply with tons of ideas! Brake fluid was dirty as hell with moisture in there. Florida owned truck. Excellent condition overall but poor preventative maintenance methinks. Am i being naive thinking most of these don't require total MC replacement?!

 

[tbisaacs]

How did you bleed the rears? You don’t pump them like you do the front. You crack the bleeder and hold the pedal down with the key on and let the Abs pump push fluid though.

There is also a techstream utility that helps with bleeding that pushes bubbles through the master cylinder.

I wouldn’t start with replacing the MC. Unlike the 100 series, failures are rare.

 

[Sandroad]

If the odd stuff started right after the brake work, I would start with the suggestions from @bloc and @tbisaacs and do a complete brake fluid replacement again with the proper procedures. I suspect air in the system from improper bleeding.

 

[Wstclx2001]

How did you bleed the rears? You don’t pump them like you do the front. You crack the bleeder and hold the pedal down with the key on and let the Abs pump push fluid though.

There is also a techstream utility that helps with bleeding that pushes bubbles through the master cylinder.

I wouldn’t start with replacing the MC. Unlike the 100 series, failures are rare.

Friend of mine helped me and used a pressure bleeder he has. Fluid was dirty and according to Lexus, who did some recall remedies the past owner didnt take it in for, it had moisture in there. I think I'm gonna tackle this myself and do as you said. I also found another thread with taco and scooby who shared the entire sequence for the brake bleed procedure.

 

[Wstclx2001]

If the odd stuff started right after the brake work, I would start with the suggestions from @bloc and @tbisaacs and do a complete brake fluid replacement again with the proper procedures. I suspect air in the system from improper bleeding.

Ok sounds good thanks for the advice. The thread linked below seems to have a pretty good summary of what to do and it echoes what everyone has shared here. Will report back:

Thread 'What is the brake bleed sequence for 200?'

Mar 23, 2018

Just picked up a 2010 LC and baselining my fluids.

Can someone tell me the brake bleed sequence for a 200 series? I am assuming PS Rear, DS Rear, PS Front, DS Front.

Thanks!

• NHouston
• Replies: 27
• Forum: 200-Series Cruisers

 

[Wstclx2001]

How did you bleed the rears? You don’t pump them like you do the front. You crack the bleeder and hold the pedal down with the key on and let the Abs pump push fluid though.

There is also a techstream utility that helps with bleeding that pushes bubbles through the master cylinder.

I wouldn’t start with replacing the MC. Unlike the 100 series, failures are rare.

The abs motor buzzes briefly upon start up then after pressing the pedal which others say is annoying but normal, makes the whoosh/hiss sound on pedal press and on release too but it's brief and only associated with actuation of brake pedal (apparently also common occurrence on these trucks), then i see those bubbles in reservoir after releasing pedal...sure hope it isnt brake booster assembly/MC job

 

[Wstclx2001]

How did you bleed the rears? You don’t pump them like you do the front. You crack the bleeder and hold the pedal down with the key on and let the Abs pump push fluid though.

There is also a techstream utility that helps with bleeding that pushes bubbles through the master cylinder.

I wouldn’t start with replacing the MC. Unlike the 100 series, failures are rare.

Update here: the bubbles occur specifically when the pedal is released after pressing. The google ai powered response says that based on this one symptom alone, it's definitely a seal gone bad in the master cylinder and it all has to be replaced immediately.

My hunch is the bubbles in the reservoir pre-dated the brake work based on the noise it makes when the pedal is released and bubbles form.

As mentioned when i got this truck, brakes were super spongy and especially when starting the truck up pedal would be slightly sticky at the top.

Got new front pads and rotors and a brake fluid exchange/bleed. The brake pedal seems pretty dang hard now with good stopping power. Only thing new since the brake work I had that issue on the long road trip where it would be sticky at the top.

Any thots given the stickiness at top + bubbles in reservoir on pedal release?

Thanks!
Clx

 

[bloc]

To me this is too specific/niche for ai to have any credibility. I’d consider bringing it to a trusted Toyota mechanic and have them take a look.

 

[Wstclx2001]

To me this is too specific/niche for ai to have any credibility. I’d consider bringing it to a trusted Toyota mechanic and have them take a look.

Ok i think I'll do that. Thanks for your reply.

The following thread describes a good amount of what I'm dealing with but i did the thing where you pump the brakes 40 times and my brake fluid level was definitely over the max:

Thread 'Brakes ...... Overdue write-up.'

Nov 1, 2020

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 master assembly, replaced with new. If you have to ask question, on "how to", your not qualified to work on the master.

My hope is below link will give better understanding as to what we can do to reduce brake failure and what to watch for. The info is from my experiences and my thinking, as to what...

• 2001LC
• Replies: 161
• Forum: 100-Series Cruisers

• 
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That said, my motor only runs like 13 seconds or something so I'm not near that 40 second max limit he references.