Brake Failure_uzj100 Power Brake booster repair- (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Found out a it more about the motor. The front bearing (behind the brush holder) just pulls out through the brushes.
The brush holder itself seems to be difficult to remove as the leads to the terminals on the outside are welded to the copper/brass conductors of the brush holder. That also goes for the brushes, not that easy to change. My brushes are actually less than 50 % worn, so I'll just leave them in. The damage to one brush cable is on 1/7 of the square, so I'll just clean it up a bit. All the debris and products of corrosion, together with the frayed copper threads would have been enough to make it noisy. A bit of PM in there from time to time is probably a good way of extending the servicable life.
I'll try to source new bearings: (dimensions in mm) (iD, oD, thick)
Front: 8 - 22 - 7, type NSK 608D10, plastic sealed (- it looks like)
Rear: 6 - 15 - 5, type NMB R-1560KK, metal sealed both sides.

P4097211-s.jpg

P4097221-s.jpg
 
Last edited:
Hi there, i had no problem with the booster pump motor until i found brake oil all over the place and dripping from the frame. I checked the engine bay could not find a big leak, but smoke coming out of the black plastic protector of the wire harness, which is connecting the booster pump motor to the hydraulic brake booster. I have not dismantled the booster pump motor yet, but the repair manual says the wire harness is a non reusable part . Why ? Mine looks fine and i don't want to remove the complete hydraulic booster unit only to replace this small wire harness.

Before i forget , a couple of weeks ago more or less all the warning lights in my dashboard came on . Is there any relation between these issues? ( The same happened to my other Landcruiser same specs but 227000 km from the same production month!)

I guess with the smoke coming out , there is something wrong with the booster pump motor or only burning brake fluid on the wire harness? Has this unit its own fuse? Which one is it? Any idea or solution is highly appreciated . Saludos desde Centroamerica.

Car : Landcruiser 100, Intercooler diesel engine, 210000 km , 2002,Automatic,
 
Found out a it more about the motor. The front bearing (behind the brush holder) just pulls out through the brushes.
The brush holder itself seems to be difficult to remove as the leads to the terminals on the outside are welded to the copper/brass conductors of the brush holder. That also goes for the brushes, not that easy to change. My brushes are actually less than 50 % worn, so I'll just leave them in. The damage to one brush cable is on 1/7 of the square, so I'll just clean it up a bit. All the debris and products of corrosion, together with the frayed copper threads would have been enough to make it noisy. A bit of PM in there from time to time is probably a good way of extending the servicable life.
I'll try to source new bearings: (dimensions in mm) (iD, oD, thick)
Front: 8 - 22 - 7, type NSK 608D10, plastic sealed (- it looks like)
Rear: 6 - 15 - 5, type NMB R-1560KK, metal sealed both sides.

View attachment 1437461
View attachment 1437462

I'd just pack it up and send to Euroton Electric and have them send you back a completed refurbed for 300 bucks
 
Hi there, i had no problem with the booster pump motor until i found brake oil all over the place and dripping from the frame. I don't really understand this sentence. Other than you think a loss of fluid destroyed your motor..

I checked the engine bay could not find a big leak, but smoke coming out of the black plastic protector (this big black connector is a solenoid pack and PCB, be very not to damaged this part) of the wire harness, which is connecting the booster pump motor to the hydraulic brake booster. I have not dismantled the booster pump motor yet, but the repair manual says the wire harness is a non reusable part (the wire harness is 2 10awg wires, just replace them and crimp new lugs) Why ? Mine looks fine and i don't want to remove the complete hydraulic booster unit only to replace this small wire harness. - Look, just replace the little electrical motor only, don't break into anything else, use all your old stuff and put back on vehicle

Before i forget , a couple of weeks ago more or less all the warning lights in my dashboard came on . Is there any relation between these issues? ( The same happened to my other Landcruiser same specs but 227000 km from the same production month!)

I guess with the smoke coming out , there is something wrong with the booster pump motor or only burning brake fluid on the wire harness? Has this unit its own fuse? Which one is it? Any idea or solution is highly appreciated . Saludos desde Centroamerica.

Car : Landcruiser 100, Intercooler diesel engine, 210000 km , 2002,Automatic,
 
Bottom line i had a very successful day. What happened : I removed the booster pump motor unit from my other Landcruiser 1 which is the same production month and installed it in my work horse Landcruiser 2. The unit is identical and worked fine from the beginning . Now the best : all the warning lights in my dashboard came off!! So this was the problem , the burned electric motor of the booster pump!

Before i install a new part i try to find out why the old part failed not to ruin the new part right away. So i opened the electric motor and found a wet cage filled with the dust of the carbon . Normally a electric motor is not wet inside . I dismantled everything and found the drain hole which is covered with a black plastic fitting completely clogged . So a little bit of brake fluid found its way over the years into the motor and could no flow out because of the clogged hole.
So it is very important to clean every year this drain hole with a wire and replace the brushes every 5 years i would say.
 
I opted for replacing the bump and accumulator, through Mud vendor ranma21- I also rebuilt the master cylinder. About 1200 all together. One could save a couple of hundred dollars by rebuilding the motor and replacing the accumulator with a new one.

Gil
Hi Gil - Im trying to do some work on my 99 LX including this dreaded brake issue and wondered as another fellow Venturan if I could pick your brain a little via PM email or phone? Thanks either way for your info here :)
Scott
 
I'd just pack it up and send to Euroton Electric and have them send you back a completed refurbed for 300 bucks
old old thread, but i just requested a quote from them, have you heard of folks having good luck with the rebuilt unit? Thinking of doing this preventatively

update, just got the official quote at $265, potentially more after part is received but, it seems pretty fair. Idk what the turnaround is though
 
Last edited:
old old thread, but i just requested a quote from them, have you heard of folks having good luck with the rebuilt unit? Thinking of doing this preventatively
update, just got the official quote at $265, potentially more after part is received but, it seems pretty fair. Idk what the turnaround is though
Depends on what the problem is, and what you mean by "the rebuilt unit". If the motor is the problem, and the master itself is good, then it is worth while to fix the motor. This would often be the case when the motor is exposed to brake fluid, either because of the common mistake of overfilling (RTFM) or from leaking reservoir grommets, as brake fluid is aggressive.
It is in any case a good idea to open the motor to check it, before you are stranded.
 
Depends on what the problem is, and what you mean by "the rebuilt unit". If the motor is the problem, and the master itself is good, then it is worth while to fix the motor. This would often be the case when the motor is exposed to brake fluid, either because of the common mistake of overfilling (RTFM) or from leaking reservoir grommets, as brake fluid is aggressive.
It is in any case a good idea to open the motor to check it, before you are stranded.

currently experiencing no issues other than dragging calipers. Rebuilding calipers and replacing brake lines, but figure while the system is cracked open (and I’m waiting for parts) might do the booster too
 
Found out a it more about the motor. The front bearing (behind the brush holder) just pulls out through the brushes.
The brush holder itself seems to be difficult to remove as the leads to the terminals on the outside are welded to the copper/brass conductors of the brush holder. That also goes for the brushes, not that easy to change. My brushes are actually less than 50 % worn, so I'll just leave them in. The damage to one brush cable is on 1/7 of the square, so I'll just clean it up a bit. All the debris and products of corrosion, together with the frayed copper threads would have been enough to make it noisy. A bit of PM in there from time to time is probably a good way of extending the servicable life.
I'll try to source new bearings: (dimensions in mm) (iD, oD, thick)
Front: 8 - 22 - 7, type NSK 608D10, plastic sealed (- it looks like)
Rear: 6 - 15 - 5, type NMB R-1560KK, metal sealed both sides.

View attachment 1437461
View attachment 1437462
How did you successfully remove the motor from the part of the case that holds the brushes? I can't seem to figure out how it "releases" in order to fully separate.

Thanks!
 
How did you successfully remove the motor from the part of the case that holds the brushes? I can't seem to figure out how it "releases" in order to fully separate.
Iirc, I just pulled the shaft/armature with the bearing on it out through the brush rigging, but it's been a few years...
 
old old thread, but i just requested a quote from them, have you heard of folks having good luck with the rebuilt unit? Thinking of doing this preventatively

update, just got the official quote at $265, potentially more after part is received but, it seems pretty fair. Idk what the turnaround is though
I'd just pack it up and send to Euroton Electric and have them send you back a completed refurbed for 300 bucks
Does Eurotron rebuild the entire master cylinder and booster unit or just the booster pump?
 
Necroposting here since this post shows up at the top at google search.


Rebuild service ABS pumps. Looking at the feedback - great service.
Mine died at 230k. Original since 1999. Researching my options...
 
Let's continue necroposting :)
Looks like my problem was in the rust on contacts. Take a look at the pics attached. Drilled out and removed rusted fasteners, careful, the contact points don't like bending and will break off.
Applied power to the motor - seems to be alive. Debating if I should check inside, while I'm here. Maybe dust off, see if brushes still there.
1679180961904.png
1679180980782.png
1679181001285.png
1679181017141.png

2023-03-18 19_04_47-Land Cruiser FSM - Google Drive — Mozilla Firefox.png
 
Let's continue necroposting :)
Looks like my problem was in the rust on contacts. Take a look at the pics attached. Drilled out and removed rusted fasteners, careful, the contact points don't like bending and will break off.
Applied power to the motor - seems to be alive. Debating if I should check inside, while I'm here. Maybe dust off, see if brushes still there.

View attachment 3276093
Open motor and inspect!

The rusted fastener, are a cause of motor commutator failure very often. The increased resistances cause premature wear of the copper bushes ride (contact) on. What typically happens is, we get one or more dead spots on commutator. Your work has resulted in some movement of commutator to brush contact points. So now jumping with 12V fires it up. But sooner or later, bushes will end up back on a dead spot.
 
  • Like
Reactions: Dmi
Thanks for pushing wonderful people!

Happy to report, brushes have plenty of life. Total length - 10mm, usable (before the wire) - 6mm. The commutator tho, worn out almost to the core. Measured 0.99mm groove that brushes carved into it. Can't measure the thickness of the copper, commutator made of, but it is somewhere in the range of 1-1.5mm.
Deemed sketchy at this point.

1679261439390.png

1679261509110.png

1679261662352.png

1679261771806.png

1679261791967.png

I've been through inside of quite a few motors, but never seen brushes survive longer then commutator.
On the other hand, it's original from 1999 and more then 230K miles on it.
Impressive.

Really thinking on getting 47070-60010 ABS PUMP BRAKE MASTER CYLINDER BOOSTER MOTOR 4RUNNER REPAIR KIT | eBay - https://www.ebay.com/itm/144028085078 and forgetting. Going new pump or assembly is a little out of reach.
 
Last edited:
Thanks for pushing wonderful people!

Happy to report, brushes have plenty of life. Total length - 10mm, usable (before the wire) - 6mm. The commutator tho, worn out almost to the core. Measured 0.99mm groove that brushes carved into it. Can't measure the thickness of the copper, commutator made of, but it is somewhere in the range of 1-1.5mm.
Deemed sketchy at this point.


I've been through inside of quite a few motors, but never seen brushes survive longer then commutator.
On the other hand, it's original from 1999 and more then 230K miles on it.
Impressive.

Really thinking on getting 47070-60010 ABS PUMP BRAKE MASTER CYLINDER BOOSTER MOTOR 4RUNNER REPAIR KIT | eBay - https://www.ebay.com/itm/144028085078 and forgetting. Going new pump or assembly is a little out of reach.
Very common to find commutator copper worn before brushes. If brake control wire has corrosion on contacts. I see this time and time again. It is why I always check wire contacts under the boot during inspection of brakes system.
Cause: brake fluid spillage on control wires travel into boots, in order of most common way it happens:
1) Overfill reservoir
2) press brake pads apart without opening bleeder
3) sloppy fill.

Note: Thickness, is depth to black line between copper section.
 
  • Like
Reactions: Dmi

Users who are viewing this thread

Back
Top Bottom