Poll on total brake failure in 100 series (3 Viewers)

Has your 100 series LC experienced total -or near total- brake failure?

  • No.

    Votes: 1,189 74.3%
  • Yes. My truck had between 0 and 50k miles at the time.

    Votes: 1 0.1%
  • Yes. My truck had between 50k and 100K at the time.

    Votes: 13 0.8%
  • Yes. My truck had between 100K and 150k at the time.

    Votes: 69 4.3%
  • Yes. My truck had between 150k and 200k at the time.

    Votes: 126 7.9%
  • Yes. My truck had between 200k and 250K at the time.

    Votes: 117 7.3%
  • Yes. My truck had between 250k and 300k at the time.

    Votes: 67 4.2%
  • Yes, My truck had over 300k at the time.

    Votes: 32 2.0%

  • Total voters
    1,601

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View attachment 2790006Voted. I won’t say it’s a complete failure, but after getting the screeching seagull a few times I would say failure was imminent. I replaced the whole brake assembly. Here’s what my motor looked like, I think I broke the magnet on removal but I didn’t feel a big break so idk.
The break on the piece to the left looks fresh but the smaller pieces to the right look like they have been cracked for some time with the dirty surface, maybe it had a small split?
 
There are 2 key areas, which I'll elaborate on after the part goes live. One is the heat dissipation hole on the OEM unit that allows water and oil to enter and contaminate the electricals. We moved the location of this hole to mitigate the issue. Second has to do with an area inside the alloy section of the pump where the factory machining process has tolerance control issues. That's why some OEM pumps last longer than others.

Can you please provide more info now that the product is released?
 
Does anyone know exactly why the intermediate “screeching seagul” sound happeneds? My 03 251k LX drives perfect with no errrors until 40min-50min. I get seagul screech accompanied with dash lights. I’ve never lost brake pressure ever. Happened on 4 drives now. I replaced black accumulater motor (new) so far and still get seagul into a 40 min drive. I also replaced the accumulater plunger and spring. Still getting seagul screeches. Does anyone know if this issue is the accumulater itself or is it a master cylinder issue? Maybe fluid creeping past a seal u see extreme pressure.
 
Does anyone know exactly why the intermediate “screeching seagul” sound happeneds? My 03 251k LX drives perfect with no errrors until 40min-50min. I get seagul screech accompanied with dash lights. I’ve never lost brake pressure ever. Happened on 4 drives now. I replaced black accumulater motor (new) so far and still get seagul into a 40 min drive. I also replaced the accumulater plunger and spring. Still getting seagul screeches. Does anyone know if this issue is the accumulater itself or is it a master cylinder issue? Maybe fluid creeping past a seal u see extreme pressure.
Internal MC seal is bad, non replaceable, need new MC.
 
Does anyone know exactly why the intermediate “screeching seagul” sound happeneds? My 03 251k LX drives perfect with no errrors until 40min-50min. I get seagul screech accompanied with dash lights. I’ve never lost brake pressure ever. Happened on 4 drives now. I replaced black accumulater motor (new) so far and still get seagul into a 40 min drive. I also replaced the accumulater plunger and spring. Still getting seagul screeches. Does anyone know if this issue is the accumulater itself or is it a master cylinder issue? Maybe fluid creeping past a seal u see extreme pressure.
Sorry but sounds like you now need new master. Dash light accompanying the "segal" indicates; pump running excessively long. The system monitors for this and a pending DTC is likely in tech stream. This is the damager of the "segal". As pump is designed to run short periods only, but often. FSM warns us; to not run pump more than 2 minutes at a time, while running test. Excessive run times and motor runs hot, which prematurely wears it out. Loss of motor, means loss of pressure. No pressure no brakes!

I do like to see confirmation. Which is at time of sound (segal) there is ripples/bubbles coming up front of reservoir. It's then for sure master is bad, replace it!

It's very common when we work on booster side (accumulator, pump, motor, and or brake control wire) only, of brake master assembly. We bring pressure back to factory spec. Old seal in master not properly care for with regular flushing and we see seal fails. The fluid leaks pass the seal at high pressure, and we get the segal sound, IMHO!

It's for this reason, I try to gauge history and condition of fluid & flushes. Very often I see very black stained reservoir and black brake fluid. Those master really don't stand a chance 8 out of 10 times.
 
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Sorry but sounds like you now need new master. Dash light accompanying the "segal" indicates; pump running excessively long. The system monitors for this and a pending DTC is likely in tech stream. This is the damager of the "segal". As pump is designed to run short periods only, but often. FSM warns us; to not run pump more than 2 minutes at a time, while running test. Excessive run times and motor runs hot, which prematurely wears it out. Loss of motor, means loss of pressure. No pressure no brakes!

I do like to see confirmation. Which is at time of sound (segal) there is ripples/bubbles coming up front of reservoir. It's then for sure master is bad, replace it!

It's very common when we work on booster side (accumulator, pump, motor, and or brake control wire) only, of brake master assembly. We bring pressure back to factory spec. Old seal in master not properly care for with regular flushing and we see seal fails. The fluid leaks pass the seal at high pressure, and we get the segal sound, IMHO!

It's for this reason, I try to gauge history and condition of fluid & flushes. Very often I see very black stained reservoir and black brake fluid. Those master really don't stand a chance 8 out of 10 times.
My fluid is clear. I see agitation in fluid as the segul is screaming lol. There’s a guy who offers rebuild service. Including rebuilding of the master cylinder. Is this service legit?
 
My fluid is clear. I see agitation in fluid as the segul is screaming lol. There’s a guy who offers rebuild service. Including rebuilding of the master cylinder. Is this service legit?
I rebuilt mine. You just pull it out and replace the plunger. 2 :banana::banana: job.
 
My fluid is clear. I see agitation in fluid as the segul is screaming lol. There’s a guy who offers rebuild service. Including rebuilding of the master cylinder. Is this service legit?
To my knowledge, no one has perfected the inner seal replacement. But perhaps someone has. Most are just replacing plunger, which comes with it's seals. Replaceable plunger is not the issue here! IMHO!
I rebuilt mine. You just pull it out and replace the plunger. 2 :banana::banana: job.
back or closes to pedal Plunger w/seals is available from Toyota.

Brake Master seal & pluger.jpg


But this is a different seal I suspect causes "dying segal" w/associated bubbles in reservoir, that sit behind (forward of) replaceable plunger. We just see a little rod in the hole once plunger removed. It's important when replacing plunger, rod is lines up with plunger. Some force plunger in w/out lining up rod, an damage them.

Here is a picture of internal plunger rod, spring and seal. Someone posted it after being removed busting the rod. I've tried to pull them out, no go. To remove them, is too bust them. There may also be another seal deeper in behind this one.. One day I'll cut open a master and see. But for now, I can't rebuild.



Brake master inner seal & pluger.jpeg


Here we've outer and inner plunger



Brake master pluger inner and outer.png


It may be possible to get at seal from forward end of master. But factory set-up, as non serviceable, by cripping housing over what appears to be thread plug (circled in yellow).

Brake master 06 PSwitch (3).JPG

Toyota tech training, general cut away.
Brake system c.jpg
 
NO; 2006 w AHC-148k MICHIGAN
Truck is younger than most w failures but Guess i was lucky. All brakes worn out for nearly 2 yrs of neglect.. I finally replaced the rear. Plenty of meat left as you can see on the pads lolll ;p Left Rear caliper was seized.. Front next.. Waiting weeks for OEM toyota parts. Rock Auto still that guy. Make sure you buy nsk/ntn/denso/aisin. The bearing companies might send you china built bearings. Research em.
20211004_173650.jpg
 
Does anyone know exactly why the intermediate “screeching seagul” sound happeneds? My 03 251k LX drives perfect with no errrors until 40min-50min. I get seagul screech accompanied with dash lights. I’ve never lost brake pressure ever. Happened on 4 drives now. I replaced black accumulater motor (new) so far and still get seagul into a 40 min drive. I also replaced the accumulater plunger and spring. Still getting seagul screeches. Does anyone know if this issue is the accumulater itself or is it a master cylinder issue? Maybe fluid creeping past a seal u see extreme pressure.
The 'Dying Seagull' is never a good sign. Usually means new Master.
 
Master is sold as either Brake Master or brake master w/booster assembly. Unless booster motor & pump previously replaced, I recommend complete master (Master w/booster assembly for dying segal!

With new OEM booster motor you get the pump, gasket and brake control wire. Or Brake booster assembly can be purchased from Toyota, which includes accumulator also.

Only part I would/may buy rebuilt is; the brake booster motor. I would buy used from a wreck (parts rig), not one that had been pulled to for replacement.

I've had two used or rebuilt Master, clients brought me to install that come to mind:
1) One was a rebuilt from ebay for a 100 series. Total junk and rig to work for awhile. That was return and replaced with new.
2) Second one was for a 2010 200 series conversion to a 2013- turn assist. It was from Russia, out of a wreak, orso I was told by client. Good clean master with no staining in reservoir and has worked very well.

I've also replace the ABS unit (black box on side of master) with used. Came from wrecking yard and has work fine. ABS unit going bad is not common, but does happen. Some think it is cause of dying segal. I suppose possible, but not seen or heard of, dying segal corrected with just ABS unit swapped out.
 
Responding to poll today, while waiting for the tow truck.
Facts as I know them: 2006 LX470 w/155K miles. My family is on the way to a college tour without me. On a windy road heading to the main highway, the alarm, ABS and VTrac lights go on. She turns around and heads home and within 500 yards, alarm on and no brakes at all. She coasted to a safe pullout and stopped with the handbrake.

Man...wife, kid, plus 3 other people with no brakes. Kind of a major thing.

Alright, now I'll read all the posts and threads. Thanks in advance for sharing your knowledge.
 
Codes read:
C1223 Malf in ABS control
C1251 pump motor locked, open circuit pump motor
C1252 Hydrobooster pump motor malf
C1256 accumulator low pressure malf
C1340 open ckt in ctr diff lock signal

I'm shopping for a new MC now, but any ideas on the center diff lock signal?
 
Responding to poll today, while waiting for the tow truck.
Facts as I know them: 2006 LX470 w/155K miles. My family is on the way to a college tour without me. On a windy road heading to the main highway, the alarm, ABS and VTrac lights go on. She turns around and heads home and within 500 yards, alarm on and no brakes at all. She coasted to a safe pullout and stopped with the handbrake.

Man...wife, kid, plus 3 other people with no brakes. Kind of a major thing.

Alright, now I'll read all the posts and threads. Thanks in advance for sharing your knowledge.
I'm personally still surprised there is not a recall for these systems yet. Glad you all are safe, it's not a fun experience at all.
 

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