Brake Booster Assembly With Master Cylinder Replacement (3 Viewers)

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Thank you JunkCrzr89! I am still trying to sort out a techstream install. For the time being, what are alternatives to bleeding the electronic/ABS ? I’m trying to square this away to avoid other potential catastrophe like burning out my new brake booster pump. Thanks!
You could use a vacuum bleeder to get the air out at each caliper, just make sure you have the key to OFF and pump the pedal 30-40 times until it drops out before you start bleeding. To do the ABS without Techstream, the next easiest thing to do (after you’ve done the above bleeding) is drive on a dirt or gravel road and slam the brakes a few times to activate the ABS.
 
For those who want to change this part, here is a great deal.


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only $1027.99 Shipped

$500 less than what I paid few weeks ago.
 
Thanks for the Tip @TSXlg!

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Posting here because my question doesn't warrant its own thread I think. I ordered P/N 47050-60043 from Decatur recently using a similar deal as posted above. My LX470 has 145,000 mi and no problems with the current booster/master assembly, but I bought a spare to have on-hand to hopefully make it so that this is a "forever" vehicle in terms of the supply of a part that is 1) critical for safety and 2) expensive and maybe one day unavailable.

The description for 47050-60043 on Decatur says "Cylinder Assy, Brake Master W/Fluid" whereas at every other Toyota shop there's no mention of fluid. I thought when I ordered that it would include a bottle of Toyota fluid packaged separately from the reservoir. However, I was surprised to see when the part showed up this weekend that it is covered in brake fluid and it looks like the reservoir was filled at least partially with fluid upon shipment, but subsequently leaked all over the part and the box it shipped in. Has anyone else encountered this before with P/N 47050-60043, i.e. does it always ship with some fluid in it? My understanding is that brake fluid overfilling is a contributor to the booster failure observed in the 100-series so I am a little hesitant to put the part (brake fluid coating and all) back in the box for years to come.

With all of that said I am wondering what others might recommend here. Options include either 1) cleaning the part well with isopropyl alcohol before re-bagging for storage if these always ship with fluid or it's to be expected, or 2) returning the part and ordering it from another dealer when there's another promotion if this shouldn't ship "wet". Thanks in advance for any guidance!

EDIT: paging @2001LC if you don't mind giving a quick opinion - I defer to you as the brake expert on the 100-series!

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Posting here because my question doesn't warrant its own thread I think. I ordered P/N 47050-60043 from Decatur recently using a similar deal as posted above. My LX470 has 145,000 mi and no problems with the current booster/master assembly, but I bought a spare to have on-hand to hopefully make it so that this is a "forever" vehicle in terms of the supply of a part that is 1) critical for safety and 2) expensive and maybe one day unavailable.

The description for 47050-60043 on Decatur says "Cylinder Assy, Brake Master W/Fluid" whereas at every other Toyota shop there's no mention of fluid. I thought when I ordered that it would include a bottle of Toyota fluid packaged separately from the reservoir. However, I was surprised to see when the part showed up this weekend that it is covered in brake fluid and it looks like the reservoir was filled at least partially with fluid upon shipment, but subsequently leaked all over the part and the box it shipped in. Has anyone else encountered this before with P/N 47050-60043, i.e. does it always ship with some fluid in it? My understanding is that brake fluid overfilling is a contributor to the booster failure observed in the 100-series so I am a little hesitant to put the part (brake fluid coating and all) back in the box for years to come.

With all of that said I am wondering what others might recommend here. Options include either 1) cleaning the part well with isopropyl alcohol before re-bagging for storage if these always ship with fluid or it's to be expected, or 2) returning the part and ordering it from another dealer when there's another promotion if this shouldn't ship "wet". Thanks in advance for any guidance!

EDIT: paging @2001LC if you don't mind giving a quick opinion - I defer to you as the brake expert on the 100-series!

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Brake master does not come prefilled with brake fluid. You'll need ~6 to 7 bottles of Toyota, when ready to flush vehicle or install this master. It can be done with 5 bottles, but you may run short. I move extra through, so I use 7..

Manufacture ads a tiny bit of fluid, I assume as a lubricate/conditioner for seals. Boxes states clearly on outside: THIS SIDE UP. These shipper toss and roll these boxes, disregarding any thing said. FSM states to bench flush it out.

Two choices:
  • Clean all fluid off master. Make sure wires, wire sheath and inside boots are dry.
  • Put in shipping claim, for miss handle box. (I just clean)
 
Brake master does not come prefilled with brake fluid. You'll need ~6 to 7 bottles of Toyota, when ready to flush vehicle or install this master. It can be done with 5 bottles, but you may run short. I move extra through, so I use 7..

Manufacture ads a tiny bit of fluid, I assume as a lubricate/conditioner for seals. Boxes states clearly on outside: THIS SIDE UP. These shipper toss and roll these boxes, disregarding any thing said. FSM states to bench flush it out.

Two choices:
  • Clean all fluid off master. Make sure wires, wire sheath and inside boots are dry.
  • Put in shipping claim, for miss handle box. (I just clean)

Roger that - thanks a ton for the background info. Was scratching my head as to why there was fluid in it but it makes sense to condition seals for longer-term storage. You were absolutely right about the lack of a "this side up" sticker or label on the box I received. I am going to go with your first choice since I suspect any other master unit that I could order would run into the same thing during shipping. Thanks again for chiming in!
 
Roger that - thanks a ton for the background info. Was scratching my head as to why there was fluid in it but it makes sense to condition seals for longer-term storage. You were absolutely right about the lack of a "this side up" sticker or label on the box I received. I am going to go with your first choice since I suspect any other master unit that I could order would run into the same thing during shipping. Thanks again for chiming in!
To be clear. Box is clearly labeled this "side up". It's preprinted symbols "Side Up" and "Fragile". The issue is the carrier. You can sticker them and you want, GLASS, FAGILE, THIS SIDE UP, etc.

Other than local pickup. Decatur is the only Dealership I'll order Masters, FDS, Radiators, mufflers or any part that tends to get shipping damage. Decatur (Eric) opens the OEM parts box and repacks. His boxes can be bounced from 10' and rolled down a bumpy hill.
 
Just wanted to say thanks to all the posts in here. I recently went hog wild and changed out the master cylinder, calipers, lines, rotors, and pads all at once with OEM parts. There was really nothing “wrong” with my brakes before, but the master cylinder was at 40sec for the cycle time so I figured I might as well do this all at once.

While all the videos for master cylinder replacement are helpful, they are all very long. Don't let this intimidate you. This was a pretty easy job. The hardest part was just figuring out the bleeding, but that also wasn't too bad I guess.

For bleeding, I'm still not totally sure if you really need techstream here, but between that, my fluid extractor vacuum bleeder, and a stick on the pedal I was able to get a nice stream of new fluid all by myself without needing an assistant to pump the brakes. For those looking to dive more into bleeding, this was also a great thread: Good brake bleeder for 100? Going to do my rear brakes - https://forum.ih8mud.com/threads/good-brake-bleeder-for-100-going-to-do-my-rear-brakes.1239422/page-3

Finally, I have to say the results were quite surprising! While the brakes felt pretty good before, they felt even better after I was done! Not sure if it was the pads, lines, master cylinder, or calipers, but in any case the brakes are even more responsive now and stop very high up on the pedal. I hope I’m good for another 250k miles now!

Getting brakes crazy
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Soooo nice and new
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I am wondering if someone could help figure out what part number to get? my local toyota parts guy was not sure and said it could be either.
it is a year 2000.
 
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I am wondering if someone could help figure out what part number to get? my local toyota parts guy was not sure and said it could be either.
it is a year 2000.
First, you'll more than likely want the whole brake master, which is 47050-60041 BRAKE BOOSTER ASSY, W/MASTER CYLINDER 07.1999-08.2000, not just Master.

Your VIN should tell you. If you use it, when ordering, you're covered for replacement if they say it's correct.

The difference in 2000, is wire housing block for pressure sensor. Build date July 1999 thru Aug 2000 Type A (89637-30030 SENSOR, OIL PRESSURE July 99 08.2000, pressure SW inline wire) Master w/booster P/N ending in 41.
All, after that date, have type B oil pressure sensor. Which is triangular shape wire housing block to sensor.

So look at your Brake booster assy w/Master cylinder. See which sensor. Then punch VIN # in at www.partsouq.com. Check it's parts diagram for pressure sensor in the master.

My notes say build date thru to Aug 2000. My recollection is up to January 2000 is type B. Sensor is the key to getting correct master.

Master 07.jpg

Type A pre 2001 and some early 2000
Brake master Pswitch OO donor (1).JPG
mid 2000 - 2007.jpg


Type B 2001 - 2007 some late 2000
Type B PS sensor.jpg
 
First, you'll more than likely want the whole brake master, which is 47050-60041 BRAKE BOOSTER ASSY, W/MASTER CYLINDER 07.1999-08.2000, not just Master.

Your VIN should tell you. If you use it, when ordering, you're covered for replacement if they say it's correct.

The difference in 2000, is wire housing block for pressure sensor. Build date July 1999 thru Aug 2000 Type A (89637-30030 SENSOR, OIL PRESSURE July 99 08.2000, pressure SW inline wire) Master w/booster P/N ending in 41.
All, after that date, have type B oil pressure sensor. Which is triangular shape wire housing block to sensor.

So look at your Brake booster assy w/Master cylinder. See which sensor. Then punch VIN # in at www.partsouq.com. Check it's parts diagram for pressure sensor in the master.

My notes say build date thru to Aug 2000. My recollection is up to January 2000 is type B. Sensor is the key to getting correct master.

thank you so much. partsouq has me shown as Type A sensor and looks to be accurate with your pictures. will go PN -41.
 
Despite the change in sensors is the BMC unit the same? I bought a rebuilt one and they sent me what seems to be a different unit.

Reservoir is not as tall and the sensor is a triangle shape. Think it might be for a GX470…or a later model LX470.

Are 03+ LX470 BMC compatible with 2000 and below models?
 
i was dealt the dreaded C1251 code a few weeks ago… never lost brakes, the alarm and ABS/Brake lights would go off after sitting for a bit, then stay on longer and longer. No leaks, or loss of fluid. Vehicle drove and braked fine. My kids and wife also use this machine sometimes so I don’t fool around with brake issues, had to fix it.

I just finished the install.. The ‘Timmy the Tool Man video’ is a good resource for removing all that stuff under the dash, but this is TOTALLY not necessary. a wobble extension and a few other deep sockets made easy work of this. Also, after de-pressurizing the system via the 40 pumps, very little leakage, though i capped and plugged everything anyway. when putting in the new unit, I also recommend getting the four mounting bolts inside just finger tight, so you can wiggle the assembly around a bit, while attaching the brake lines, being very careful not to cross-thread, then tighten it down to the firewall. Also be gentle with the charcoal canister thing.. I can see it would be easy to damage removing that back hose, or other stuff, that thing feels delicate.

Honestly, this went a lot smoother than i figured it would?

I searched for a new one, but was hoping for other options. Thanks to this wonderful forum, I found one. I had Andy Le send me one. He is very easy to work with.

I’ll post a report after I bleed the system, and put a few miles on. Any advice on bleeding would be helpful.. i’m not using Tech Stream, but my OBD tool has the option for bleeding, and I’m fairly clear on how to do it, without either.

I want to thank everyone on this forum for all of the input and information.
 
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i was dealt the dreaded C1251 code a few weeks ago… never lost brakes, the alarm and ABS/Brake lights would go off after sitting for a bit, then stay on longer and longer. No leaks, or loss of fluid. Vehicle drove and braked fine. My kids and wife also use this machine sometimes so I don’t fool around with brake issues, had to fix it.

I just finished the install.. The ‘Timmy the Tool Man video’ is a good resource for removing all that stuff under the dash, but this is TOTALLY not necessary. a wobble extension and a few other deep sockets made easy work of this. Also, after de-pressurizing the system via the 40 pumps, very little leakage, though i capped and plugged everything anyway. when putting in the new unit, I also recommend getting the four mounting bolts inside just finger tight, so you can wiggle the assembly around a bit, while attaching the brake lines, being very careful not to cross-thread, then tighten it down to the firewall. Also be gentle with the charcoal canister thing.. I can see it would be easy to damage removing that back hose, or other stuff, that thing feels delicate.

Honestly, this went a lot smoother than i figured it would?

I searched for a new one, but was hoping for other options. Thanks to this wonderful forum, I found one. I had Andy Le send me one. He is very easy to work with.

I’ll post a report after I bleed the system, and put a few miles on. Any advice on bleeding would be helpful.. i’m not using Tech Stream, but my OBD tool has the option for bleeding, and I’m fairly clear on how to do it, without either.

I want to thank everyone on this forum for all of the input and information.
You can bleed the rear easily: Ignition on foot on paddle and open the bleeder nipple.. Be ready to catch a lot of fluid. 3-5 seconds is sufficient per side. Refill the reservoir.

Front can bleed on its own: Activate ABS on a gravel road several times.

This is the thread I did with the help of a video posted on youtube.

 
i was dealt the dreaded C1251 code a few weeks ago… never lost brakes, the alarm and ABS/Brake lights would go off after sitting for a bit, then stay on longer and longer. No leaks, or loss of fluid. Vehicle drove and braked fine. My kids and wife also use this machine sometimes so I don’t fool around with brake issues, had to fix it.

I just finished the install.. The ‘Timmy the Tool Man video’ is a good resource for removing all that stuff under the dash, but this is TOTALLY not necessary. a wobble extension and a few other deep sockets made easy work of this. Also, after de-pressurizing the system via the 40 pumps, very little leakage, though i capped and plugged everything anyway. when putting in the new unit, I also recommend getting the four mounting bolts inside just finger tight, so you can wiggle the assembly around a bit, while attaching the brake lines, being very careful not to cross-thread, then tighten it down to the firewall. Also be gentle with the charcoal canister thing.. I can see it would be easy to damage removing that back hose, or other stuff, that thing feels delicate.

Honestly, this went a lot smoother than i figured it would?

I searched for a new one, but was hoping for other options. Thanks to this wonderful forum, I found one. I had Andy Le send me one. He is very easy to work with.

I’ll post a report after I bleed the system, and put a few miles on. Any advice on bleeding would be helpful.. i’m not using Tech Stream, but my OBD tool has the option for bleeding, and I’m fairly clear on how to do it, without either.

I want to thank everyone on this forum for all of the input and information.
FWIW: Remanufactures Brakes masters, are not the way to go IMO.

Bleed:
 
You can bleed the rear easily: Ignition on foot on paddle and open the bleeder nipple.. Be ready to catch a lot of fluid. 3-5 seconds is sufficient per side. Refill the reservoir.

Front can bleed on its own: Activate ABS on a gravel road several times.

This is the thread I did with the help of a video posted on youtube.

Thanks again, NissanH. This seems to be the preferred method. Waiting on some extra Toyota brake juice to come to my door, then I’ll give it a go.

How do the front brakes ‘self bleed’? This is a new one for me.
 
FWIW: Remanufactures Brakes masters, are not the way to go IMO.

Bleed:
I guess we’ll see how it goes. At less than half the cost of an original, and a few positive reviews, I decided to try Andy out.

Thanks for the links, 2001LC, and all the other info/photos/diy/etc. you have on our unique brake system.
 
Got more Toyota fluid in today. Did the bleed out of the rear, as per the FSM and suggestions here, then did the front the old fashioned way. A lot of air in the front, it seemed, but finally clear and air free after a few cycles. Found a caliche parking lot nearby to get the ABS to turn on after a couple of hard brake applications. Everything seems ok.

Pedal is nice and firm. Drives and brakes as normal, maybe better. No codes or lights. Plan to do a few more checks and tests (run time, re-bleed, etc.) in a few days.

Thanks again to everyone for this forum.
 
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