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

[Dirt J]

Got it.
I'm learning pretty quickly I cannot find 47050-60041 on any dealer website around me, however I see 47050-60042. I found other sites, like Toyotapartsdeal.com which has noted in fine print stating "Manufacturer supply shortage". Glad I don't need this right now.

I had forgotten I read about that on another thread since I got mine. Looks like info on swapping connectors here.

 

[Unrulykid]

Which connector?
View attachment 4126093

The brake system electrical connector discussed is here…

This connector…

On my 2002 LX, the triangular shaped connector has this wiring pinout.

Changing to the newer triangular style connector body has been proven to function correctly, and seems the most practical and reliable solution rather than swapping the old flat connector style sensor into a new brake booster assembly. Especially considering the unknown diameter and depth of the old style sensor.

The newer style triangular shaped wire connector body is Toyota part # 90980-11451.

That’s what I would do…

 

[frawstme]

Are 100 series with VSC more prone to these issues?

My brake booster takes about 36 seconds before it stops running and braking is a bit soft. Getting brake flush and new lines done at Toyota in about two weeks, these threads have me worried

 

[trdcorolla]

Are 100 series with VSC more prone to these issues?

My brake booster takes about 36 seconds before it stops running and braking is a bit soft. Getting brake flush and new lines done at Toyota in about two weeks, these threads have me worried

How big are your tires? When I had 32's and 33's I felt like the brakes were fine. When I moved to 34's I felt like the brakes felt weak, like I had to push down a lot more to stop, sometimes making my right leg really tired on long drives. I upgraded to 03+ front calipers (which have ~1.5mm bigger pistons) and the braking was massively better. Thanks @2001LC for this info.

 

[Les Summer]

Ok, so I'm have having issues with brake master cylinder but its seems slightly different than what I've in the threads and almost like I have of an electrical issue maybe that may or may not be solved by replacing the whole master cylinder.

(for context its a 1999 LC with 572,000 miles)
This past Tuesday on a fairly warm morning my wife turned the car on, the brake motor came on normal but after 20 or so seconds got a bit louder with a bit of screeching/whistling sound (not quite as loud or constant as the screaming seagull sound I've heard on others videos) and the abs and brake light go on and off about 1.5 seconds but no alarm. Later that day I pumped the brakes 30 times and turned the key to on (without starting) and got the same intermittent screech and slowly blinking lights, if I tap the pedal during this it cuts off the noise from the brake motor/accumulator and the lights but then they come back. I tried unplugging, cleaning, leaving them disconnected for a day, and reconnecting some of the abs plugs. No change, other than after a minute or two the motor cycling normal and going screeching loud--it then stops entirely and the ABS and BRAKE light illuminate but no alarm sound.

I have checked and there are no bubbles and splashing of fluid when the screeching happens or when the motor/booster is on. It seems more like an issue with the high pressure switch. I also audibly hear a clicking (tick/tock) sound that seems almost like it is coming from the fuse box/or maybe abs box. None of the fuses look blown, but not sure about the relays. I only have a scan gauge II and a $25 code reader from amazon and neither show any codes. I'm guessing if there is ABS sensor/solenoid/fuse issues it would show up on these devices? Do I need techstream or just a better code reader? I did replace the passenger side CV on saturday, maybe I knocked the abs sensor?

I did have an issue at the end of December where on a road trip with the family the flare nut going into the three way junction on top of the rear was leaking and I had a shop cut it, reflare, and flush the brakes, and it does look like they overfilled the reservoir (and most likely not with toyota fluid). It looks like it may have over flowed since then and maybe the hygroscopic issues are affecting the wiring for the master cylinder. If that's the case it would seem replacing the whole MC assembly would take care of it.

I'm trying to figure out how I can be sure the master cylinder vs an electrical problem elsewhere (rain egress in the a pillar getting on wiring, abs sensor, fuses/relays, etc)?

572k on the original brake booster? Holy cow.

 

[frawstme]

How big are your tires? When I had 32's and 33's I felt like the brakes were fine. When I moved to 34's I felt like the brakes felt weak, like I had to push down a lot more to stop, sometimes making my right leg really tired on long drives. I upgraded to 03+ front calipers (which have ~1.5mm bigger pistons) and the braking was massively better. Thanks @2001LC for this info.

I have 33" tires and they still feel a bit spongy. I did go down the rabbit hole reading about this brake failure between this thread and the pinned thread, so now my paranoia is extra high. I was looking for trending differences between how many people were having the failure with VSC or without it, but that's not really noted on these threads.

Hoping that after my fluid is changed that I'll see a difference, but my fluid really doesn't look bad at all right now. It's not dark or dirty. My brake pads are nearly new on the front and at about 50% on the back. I'm getting new lines put in all the way around when I do the fluid exchange, although none are currently leaking.

 

[hotdawwgman]

The brake system electrical connector discussed is here…

View attachment 4126292

This connector…

View attachment 4126300

On my 2002 LX, the triangular shaped connector has this wiring pinout.

View attachment 4126293

Changing to the newer triangular style connector body has been proven to function correctly, and seems the most practical and reliable solution rather than swapping the old flat connector style sensor into a new brake booster assembly. Especially considering the unknown diameter and depth of the old style sensor.

The newer style triangular shaped wire connector body is Toyota part # 90980-11451.

That’s what I would do…

Literally had to do this on my 2000 LX last month with 266k miles. Re-pinned and have zero issues with the new booster.