Brake Booster Assembly With Master Cylinder Replacement

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Refreshing a master. With booster assembly (motor, pump, accumulator, brake control wire) components and or master plunger as needed. Is fine, if a good master & ABS unit.

But no one to my knowledge, has rebuilt the master and or ABS unit. Has someone?
 
about 100 miles on the rig after installing the rebuilt MC/booster combo. Run times seem normal after overnight, no loss of fluid. Pedal feels fine, actually better than before.

Going to re-bleed it this weekend, but so far, so good.
 
Sort of related question. I just replaced the entire master cylinder assembly (PN 47050-60010, brand new OEM) on my 98 and I am wondering how frequently the booster motor should run? There is lots out there about the time required to fill the accumulator but I can't find much about how often it should run. I replaced the entire master assembly because of concerning frequent recharges (which were also getting louder/rattlier) and a very low initial pedal pump engagement. After replacing with PN 47050-60010, the vehicle's braking is far better, the charging of the system is far quieter, but the system still charges frequently -- the motor currently runs every 5-6 full (to the floor) pumps of the pedal, takes less than 10 seconds to fill and shut off. I am wondering if something is going on here.

thx!
 
" the motor currently runs every 5-6 full (to the floor) pumps of the pedal, takes less than 10 seconds to fill and shut off. I am wondering if something is going on here."


That description sounds pretty normal from my experience.

I realized few days ago that since installing a brand new MC assembly, that I can no longer hear the sounds of the MC/brake booster running from inside of vehicle as was the case prior to the replacement.
 
Normal. The booster motor is designed to run frequently and often, for short duration (5 to 10 seconds is good). Every time brake pedal depressed, accumulator expel energy (pressure). Once pressure drops to a predefined point, motor fires-up to bring pressure back up.

Note: ABS brake should never be pumped. Press once and hold only..

Test brake Alarm working:
With key on, pump pedal rapidly. Alarms sound off. The better the master/booster assy, brake fluid, lines and seals. The more pumps until we hear alarms.
 
I've done a bit of search, but not found anything regarding using a Bosch electric booster in lieu of spending $ to fix/replace the oem booster. Can anyone familiar with these comment on why this would, or would not, be a viable alternative? Seems pretty simple/inexpensive to me. (Tesla or Honda electric brake boosters - both made by Bosch)
 
I imagine you would lose ATRAC, VSC and ABS. Most 100 owners prefer to keep those. Maybe they can be adopted but you are creeping up to a new OE booster on time/money. The 80 and earlier series folks would be more apt to use the Bosch/ iBoosters.
 
I imagine you would lose ATRAC, VSC and ABS. Most 100 owners prefer to keep those. Maybe they can be adopted but you are creeping up to a new OE booster on time/money. The 80 and earlier series folks would be more apt to use the Bosch/ iBoosters.
None of that is on my 98 other than the ABS and I have that disabled.
 
Keep in mind. Brakes are a safety component of the vehicle.

To be clear:
Booster, is the side of brake master assembly. That produce boosted hydraulic pressure (~2,500 PSI). Which pressure, is stored in the accumulator and released as brake pedal pressed. It is comprised of and can be purchased separately from Toyota.

The booster assembly:
  • Brake booster control wire
  • Booster motor.
  • Pump
  • Accumulator.
  • Seal, spring and plunger (between pump and accumulator)
The brake master, on 98-99. It is comprised of:
  • Brake master with ABS unit. 98-99 only one rear brake line, server both side. So no ATRAC. 00-up two rear lines.
  • Brake reservoir w/level sensor.
  • Grommets. (seals master to reservoir).
You can install any booster motor you like, that fits. But personally I'd only use OEM. The factory booster motor, can be rebuilt.

Bottom line:
Understanding what if anything is wrong with booster and or brake master assemble. Is key!

At 27 years old, anything wrong with assemble. Best practice: replace the whole assemble (booster w/ brake master). Good for next 25 years.


Alternatives:

One day, we'll not have new OEM available. 1999- 2020, Toyota was out of the older 1 rear brake line and some others versions. People were looking for alternatives. Some were found (search mud).

There's also, an OEM vacuum boosterstyle. Which was not used, in USA 100 series.
 
Alternatives:

One day, we'll not have new OEM available. 1999- 2020, Toyota was out of the older 1 rear brake line and some others versions. People were looking for alternatives. Some were found (search mud).

There's also, an OEM vacuum boosterstyle. Which was not used, in USA 100 series.

I'm still running the original booster on my 2005. No real signs of trouble yet. I don't like replacing working parts, especially expensive ones, but these boosters becoming no longer available (or even more expensive - tariffs...) does concern me a little bit. To the point I may pick one up at the next sale and just keep it on the shelf in the garage. Anyone else done / doing the same?
 
I'm still running the original booster on my 2005. No real signs of trouble yet. I don't like replacing working parts, especially expensive ones, but these boosters becoming no longer available (or even more expensive - tariffs...) does concern me a little bit. To the point I may pick one up at the next sale and just keep it on the shelf in the garage. Anyone else done / doing the same?
Yep. Bought a booster/master assembly when I got my LX for peace of mind. Sitting on the shelf, and I plan to install when I hit 200k mi in a couple years or if my current assembly shows any issues, whichever comes first. Also plan to do a flush with Toyota OEM fluid during the next larger service to hopefully extend the life of the current unit.

Wish I had bought an OEM windshield while I was at it; apparently they are no longer available.
 
Here I am heading to the forums for an answer that I probably already know, but wanna hear someone else tell me just for good measure. My 2000 Toyota Land Cruiser has almost 300,000 miles on it now and I have no idea if my brake booster assembly is the original. I wanna know if it’s justified if it’s smart if it’s wise even to ready myself and purchase a brand new assembly from the dealer, which is now ranging anywhere from $14-$1500 to keep on standby. Is there anyone on here that’s got their original assembly with 350 400 even 500,000 miles on it? Also is there a danger of these assemblies no longer being available from the dealer in the near or distant future?
 
Here I am heading to the forums for an answer that I probably already know, but wanna hear someone else tell me just for good measure. My 2000 Toyota Land Cruiser has almost 300,000 miles on it now and I have no idea if my brake booster assembly is the original. I wanna know if it’s justified if it’s smart if it’s wise even to ready myself and purchase a brand new assembly from the dealer, which is now ranging anywhere from $14-$1500 to keep on standby. Is there anyone on here that’s got their original assembly with 350 400 even 500,000 miles on it? Also is there a danger of these assemblies no longer being available from the dealer in the near or distant future?
I replaced my original BB assembly recently with over 400,000 miles on odometer. Definitely buy during one of sales if you plan on getting standby unit
 
Here I am heading to the forums for an answer that I probably already know, but wanna hear someone else tell me just for good measure. My 2000 Toyota Land Cruiser has almost 300,000 miles on it now and I have no idea if my brake booster assembly is the original. I wanna know if it’s justified if it’s smart if it’s wise even to ready myself and purchase a brand new assembly from the dealer, which is now ranging anywhere from $14-$1500 to keep on standby. Is there anyone on here that’s got their original assembly with 350 400 even 500,000 miles on it? Also is there a danger of these assemblies no longer being available from the dealer in the near or distant future?

I assume the booster won't be discontinued anytime soon. There's still lots of 100s out on the road. IMO the bigger risk is the unit eventually going up in price.

If you were going to store one on the shelf, (and have ~$1k to spare), now would be a good time to do it as there's a 25% off sale for a few more days. FWIW, I am/was debating doing the same. But it's an expensive part (even on sale), and my original booster appears to be working fine. I have about half the mileage you do, though.
 
Thanks @leveeguy and @rexington14
400k that's fantastic. I'm going to hold out until I getting a larger poll on this one. I'm in no mood to spend 1500.00 right now to set a Toyota part up on the shelf, although I would if I could do it comfortably. It's going to take more convincing for me to pull the trigger on this one.
 
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Still doing well on the Andy Le rebuilt unit. About to do new pads all around.
 
Crap-shoot!

Rebuild brake master, are master that had failed. If cause was only due to booster side of brake master. Rebuild is fine. But often failure, was due to improper brake fluid service. Which often result in issues with seal and or ABS unit. Bottom line; they are a crap-shoot, that odds are not in your favor.

If Andy Le, has posted anywhere, how he rebuilds and test. I'd be very interested. What I'd want to see is how he replaces the internal non replaceable seals. How he clean and test the ABS unit.
These parts can be seen here.
 

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