great informative thread on brake boosters.
Appreciate the time effort on research.
I
Appreciate the time effort on research.
I
Brakes ...... Overdue write-up. (2 Viewers)
- Thread starter 2001LC
- Start date
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I still might but what lead me to thinking about the dealer was all the threads about issues that occurred after bleeding or flushing their own brakes. I can turn a wrench but this intimidates me a bit due to the cost and potential danger of making a mistake. I'll keep reading up on it of course.
Advice: earlier today left for a weekend getaway, raining all morning, drove 100 a few miles, then after lunch departed, wet roads whole way, after about 1 hour driving through stop and go city traffic, made it to the highway. 15-20 minutes of steady 55mph and ABS, VSC (x2) and BRAKE light came on steady. Checked brakes and still worked. No alarm or anything.
Drove about 10-15 miles to a rest stop, carefully coasted to a stop. Brakes worked. Turned off, checked fluid level, it was in between the lines.
Walked the dog real quick…then back in and turned on, no lights.
Finished 30 mile trip to destination, had brakes the whole time.
Need to drive home on Monday, any thoughts on risk?
2004, 100,200 miles (not a typo). Under 40 seconds when I checked booster a few months ago but did cycle 3-5 times.
Thanks!!!
Drove about 10-15 miles to a rest stop, carefully coasted to a stop. Brakes worked. Turned off, checked fluid level, it was in between the lines.
Walked the dog real quick…then back in and turned on, no lights.
Finished 30 mile trip to destination, had brakes the whole time.
Need to drive home on Monday, any thoughts on risk?
2004, 100,200 miles (not a typo). Under 40 seconds when I checked booster a few months ago but did cycle 3-5 times.
Thanks!!!
Curious on what you’ve found 2001LC.
I seem to be weeping fluid out of a seal from the master somewhere. I double checked it wasn’t overfilled, the reservoir appears to be dry at the top and sides. Guessing it’s time to replace. Ugh dealer replaced accumulator 2 years ago. Do it all, buy once cry once.
The tee gets enough fluid to drip onto the rubber hose below.
I seem to be weeping fluid out of a seal from the master somewhere. I double checked it wasn’t overfilled, the reservoir appears to be dry at the top and sides. Guessing it’s time to replace. Ugh dealer replaced accumulator 2 years ago. Do it all, buy once cry once.
The tee gets enough fluid to drip onto the rubber hose below.
2001LC
SILVER Star
- Thread starter
- #48
Most Toyota/Lexus Dealerships, will not replace any part on the master. They just replace the whole brake master w/booster assembly ( the whole deal). For good reasons. You now know one of those reasons. Second reason is liability.
I too have found with our ageing 100 series. It's best to replace the whole assembly. One and done!
There a 3 rubber grommet at bottom of reservoir going into top of master body, can leak. These leaks would likely come down both side of master. If yours wet high up on body of master and working down RH & LH side, this may be yours! As looks wet just under reservoir and down. But pictures not good enough for me to tell, if wet up high, or just wet lower where clearly wet. If just lower wet, grommets are not likely your leak.
Another leak can be accumulator O-ring. This one tends to just be seen at bottom of accumulator and on pump. It makes its way onto bottom of booster motor. I do not think this your leak, as pump looks dry to me.
The above leaks can be stopped by replacing grommets/ O-ring.
Flare fittings of hard lines can leak. But this is very rare, unless flares nut(s) have been removed before. Your lower hard line (a rear brake line) and flare, look to have had/have oil attacking dirt. This could be flare nut leak. But I suspect it's just fluid traveling onto flare nut & hard line from leak elsewhere, in your case.
Another leak can be from weep hole at bottom of pump. Pump has a seal at input shaft, where it attaches to booster motor. If breather hole is plugged at bottom of pump, motor will suck fluid from the pump. This leak is only seen at bottom of pump & motor. So not likely yours.
*** Another leak is seals between master body and ABS unit (black plastic box and aluminum box on side of master). This one requires a new master. The seal(s) are not sold by Toyota. The leak will start on the out side (side nearest DS/LH fender USA models (LHD)) of master, but fluid may travel down and around to other side. This could be your leak. If upper master body area dry on RH side (picture side) and only wet at bottom area of this and the LH side of master.
I would clean spotless. Then watch close for first appearance on brake fluid leak This will help isolate location of leak.
awesomeissquid
SILVER Star
Have we already documented the correct part numbers by model year for the full assembly somewhere else in the thread? If not, it might be nice to have it here for future reference.
From another thread somewhere:
The correct ABS booster + master cylinder assembly depends entirely on the manufacturing date of your 100 and whether or not you have VSC:
47050-60010: without VSC; 01/1998-07/1999
47050-60012: without VSC; 07/1999-08/2002
47050-60041: with VSC; 07/1999-08/2000
47050-60042: with VSC; 08/2000-08/2002
Confirm via Partsouq.
The correct ABS booster + master cylinder assembly depends entirely on the manufacturing date of your 100 and whether or not you have VSC:
47050-60010: without VSC; 01/1998-07/1999
47050-60012: without VSC; 07/1999-08/2002
47050-60041: with VSC; 07/1999-08/2000
47050-60042: with VSC; 08/2000-08/2002
Confirm via Partsouq.
Yes, 47050-60041 has the flat/oval ABS connector.
47050-60042 has the triangular connector.
Yes it appears to be wet from the bottom of the plastic reservoir on down. Not coming down both sides yet, isolated to passenger side of master.
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2001LC
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- Thread starter
- #54
Easy enough to change out grommets to see what happens. Three grommets, two sizes IIRC. But again not common for these grommets to leak, if reservoirs never been removed and fluid care for properly.
A note: If reservoir is badly stained (blacken). This indicates fluid was not care for properly. In my grading of master health. Staining is a big negative. In these, I've found two issues:
1) All rubber seals are damaged.
2) Debris gets into ABS unit, clogging it. I've had ABS unit lock a single caliber. Only way to drive when this happens is disconnect masters power and open bleeder of stuck caliper.
One reason I replace the whole master these days, rather than patch them part by part. Long term cost go up and reliability goes down, otherwise!
@2001LC UPS is dropping off my new brake system (complete assembly: master cylinder, accumulator, ABS booster, etc) with 7 bottles of Toyota fluid today. What is the best/easiest way to get all, or as much as possible, of the old fluid out of the system?
My LC has the ABS, Brake, VSC TRAC, and VCS OFF lights illuminated along with buzzer. I'm assuming under this condition that the master will not "power bleed" to the rear lines, like for flushing the lines. Please advise. Thanks!
My LC has the ABS, Brake, VSC TRAC, and VCS OFF lights illuminated along with buzzer. I'm assuming under this condition that the master will not "power bleed" to the rear lines, like for flushing the lines. Please advise. Thanks!
I’m not overly optimistic about how often the fluid was changed, it’s stained and I’m more concerned with seals leaking again later somewhere else down the line.
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2001LC
SILVER Star
- Thread starter
- #57
If booster motor is working, pedal will not go to the floor. So you'll remove fluid from rear bleeder; key on and pedal pressed. Otherwise take off master w/res full. I just use the thread plastic plugs, that come with new master. Plug the holes as you remove each hard line. I also use rubber caps on my hardline flare nuts, to protect them.
Rinse spillage with water ASAP.
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Hmmm I think we can marked this solved. After cleaning and back and forth with a buddy. I believe we have a winner.
Yesterday, I made the mistake of asking local Toyota dealer to bleed brakes on 01 Cruiser. Picked up car in afternoon and all seemed ok, I checked for leaks quickly underneath and didn't see anything. This morning, after sitting overnight, I came out to a puddle in driveway. On inspection, i could see the drippage coming down left side frame and plastic cover, originating from what appeared to be high up on brake fluid res.
I immediately went back to dealership, worried about the ABS system (oddly enough putting the assembly in cart multiple times at sierra decatur toyota 25% off and not buying each time), asking them wth is going on here.
They pulled my truck back a ways and next thing I know the service advisor and tech are telling me its "just residual fluid" and if there was a leak, the res would be empty. They said they'd clean it off. See my receipt, says "residual", that must be dealer speak for Oops we spilled everywhere.
I wait 30 mins and get truck back. Its far from clean. I get home and start cleaning with water and cloth in some areas, brake cleaner down below. Brakes seem ok, no leaks i can see after cleaning, waiting, and driving.
A bit ago I tested the system by pumping 40 times on pedal with IGN off. At that point i noticed my fluid was 1/2 to 1" above the MAX line. The system did take about 28 seconds and by time appears healthy.
Does this mean the techs there overfilled my system, and now I need to withdraw fluid until post 40 ignition off pedal pumps the system shows right at max? And their carelessness has likely shortened by assemblies life by some unknown amount?
I immediately went back to dealership, worried about the ABS system (oddly enough putting the assembly in cart multiple times at sierra decatur toyota 25% off and not buying each time), asking them wth is going on here.
They pulled my truck back a ways and next thing I know the service advisor and tech are telling me its "just residual fluid" and if there was a leak, the res would be empty. They said they'd clean it off. See my receipt, says "residual", that must be dealer speak for Oops we spilled everywhere.
I wait 30 mins and get truck back. Its far from clean. I get home and start cleaning with water and cloth in some areas, brake cleaner down below. Brakes seem ok, no leaks i can see after cleaning, waiting, and driving.
A bit ago I tested the system by pumping 40 times on pedal with IGN off. At that point i noticed my fluid was 1/2 to 1" above the MAX line. The system did take about 28 seconds and by time appears healthy.
Does this mean the techs there overfilled my system, and now I need to withdraw fluid until post 40 ignition off pedal pumps the system shows right at max? And their carelessness has likely shortened by assemblies life by some unknown amount?
I would pump your brakes to empty, withdrawal extra fluid from reservoir. Clean spotless and see if it reappears.
If fluid is at max without depressurizing the system it could overflow out of the top iirc.
If fluid is at max without depressurizing the system it could overflow out of the top iirc.
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