Also this morning I wanted to see what a series of run times would be after evacuation of the accumulator. They were 41 39 47 44 33 32 37 35 38 31 52(brief abs light/chime) 52(brief abs light/chime) at first I thought wow it only runs long at first, but then I got the 50+ times...
Master Cylinder Rebuild - DIY (12 Viewers)
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2001LC
SILVER Star
If reservoir is low the warning will come on. Make sure you've topped according to instruction on reservoir.
Even the smallest leak and test will be over 40 seconds. I like to blow out the bleeders and then leave bleeder uncapped for a day to dry. Then cap bleeder and de-grease area of each bleeder. I'll inspect to make sure no fluid residue around bleeder after cleaning. Then actively work brakes which brings pressure up to maximum within the system. Small amounts of Brake fluid may dry and you'll not see if you wait. So inspect right away for leak. Any oil residue no matter how small indicates a leak.
Test even with a leak will usually have about the same time. So if you see 41 then 45 seconds, that's about the same. But to get higher each time hitting 90 seconds or 5 minutes is not normal for a leak. Now to get 31 to 52 seconds indicates sometime else going on.
It could indicate a few different things. One, moisture in the fluid. Moisture is reason we flush. It lowers boiling point. So each time you repeating test without a long pause, the fluid temp is raising more than new fluid (dry fluid) would. When I flush I've a procedure I use to make sure I'm getting old fluid out of accumulator. I actually evacuate accumulator about 5 times to get it and reservoir flushed first. I've done a few write-ups on this. Here's one on a 200 series which is about the same Scored 2011 LC W/79K OMG CLEAN (2012 missing link)
Other possible reasons that come to mind are, the accumulator or your pressure switch is/are failing. I suppose if fluid had a high moisture content over an extended period, pump may have gotten damaged.
I don't think your motor was the issue. Motor will sometimes run, than not run as dead spots develop on commutator. Then eventually they will not run. When motor fails system can not build pressure back up at all. Then pedal goes to the floor.
So this again brings back to your reason for replacing motor.
I'm hopefully your junk yard motor/pump/accumulator assy will fix your issue.
One more thing you need to be aware of is; factory states wire is non-reusable. It is a very pricey wire, listing at $170.
Even the smallest leak and test will be over 40 seconds. I like to blow out the bleeders and then leave bleeder uncapped for a day to dry. Then cap bleeder and de-grease area of each bleeder. I'll inspect to make sure no fluid residue around bleeder after cleaning. Then actively work brakes which brings pressure up to maximum within the system. Small amounts of Brake fluid may dry and you'll not see if you wait. So inspect right away for leak. Any oil residue no matter how small indicates a leak.
Test even with a leak will usually have about the same time. So if you see 41 then 45 seconds, that's about the same. But to get higher each time hitting 90 seconds or 5 minutes is not normal for a leak. Now to get 31 to 52 seconds indicates sometime else going on.
It could indicate a few different things. One, moisture in the fluid. Moisture is reason we flush. It lowers boiling point. So each time you repeating test without a long pause, the fluid temp is raising more than new fluid (dry fluid) would. When I flush I've a procedure I use to make sure I'm getting old fluid out of accumulator. I actually evacuate accumulator about 5 times to get it and reservoir flushed first. I've done a few write-ups on this. Here's one on a 200 series which is about the same Scored 2011 LC W/79K OMG CLEAN (2012 missing link)
Other possible reasons that come to mind are, the accumulator or your pressure switch is/are failing. I suppose if fluid had a high moisture content over an extended period, pump may have gotten damaged.
I don't think your motor was the issue. Motor will sometimes run, than not run as dead spots develop on commutator. Then eventually they will not run. When motor fails system can not build pressure back up at all. Then pedal goes to the floor.
So this again brings back to your reason for replacing motor.
I'm hopefully your junk yard motor/pump/accumulator assy will fix your issue.
One more thing you need to be aware of is; factory states wire is non-reusable. It is a very pricey wire, listing at $170.
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Thanks so much for your expertise!
Reservoir is always topped.
There is a tiny bit of residue on both rear Bleeders. So ill replace those.
Ill thoroughly bleed the accumulator when I do the rear Bleeders and pump/motor/accumulator. Will let you know what happens. If that does not work I guess I'm looking at master cylinder rebuild or more likely the whole assembly if it's the pressure sensor.
Reservoir is always topped.
There is a tiny bit of residue on both rear Bleeders. So ill replace those.
Ill thoroughly bleed the accumulator when I do the rear Bleeders and pump/motor/accumulator. Will let you know what happens. If that does not work I guess I'm looking at master cylinder rebuild or more likely the whole assembly if it's the pressure sensor.
2001LC
SILVER Star
Your welcome! But can't say I'm and expert. I've just had to deal with numerous brake issue for locals and on some of my restore projects.
I torque bleeder to spec. If they weep/leak I'll increase torque 1-2lb at a time. If by ~12ft-lbf they've not stopped weeping/leaking I replace with new OEM bleeder. Aftermarket bleeders do not work well in OEM calipers.
I torque bleeder to spec. If they weep/leak I'll increase torque 1-2lb at a time. If by ~12ft-lbf they've not stopped weeping/leaking I replace with new OEM bleeder. Aftermarket bleeders do not work well in OEM calipers.
The junk yard motor/pump/accumulator is in along with two new rear bleeders. I was problem free for the first few trips a total of about 30 in town miles. Yesterday the alarm and light came on briefly during a 6 mile trip at the beginning and several times at the end. Not sure why after removal of the booster/master and bleeding the problem goes away for 20-30 miles.
I checked the run times after evacuation at the end of this trip yesterday and got 42 45 49 48 44 38 43 33 46 45 33 33 33 33 33 32 33 33 33. Again this morning I checked it again after sitting overnight and I got 55 43 60 37 47 41 36 40 35 36 43 36 36 34 44 33 26 31 36 35. I did get 90 and 150 seconds before the junk yard part swap but nothing this high since.
At this point I think I have two options 1. master cylinder rebuild (will fix if there is an internal leak here) or 2. replace the booster/master assembly. Given comments prior "Test even with a leak will usually have about the same time ... to get 31 to 52 seconds indicates sometime else going on" it seems unlikely that the master rebuild is unlikely to fix things and that I need to bite the bullet and shell out the $$$ for the entire assembly. Any thoughts?
Not sure if this makes a difference but the service records from 7 years ago and 50K miles ago state BRAKE SERVICE ~|~CHECK AND ADVISE ABS LIGHT WAS ON ~|~ABS ACTUATOR IS NOE RESPONDING ~|~NEED TO REPLACED ABS ACTUATOR. It also states customer pay but does not list a part number. I don't know if Toyota did the repair or another shop. The Accumulator I removed did have some purple/pink marker writing on it that looked like what you would see on a junk yard part. I'm not sure what actually went down there. Probably is water under the bridge at this point.
I checked the run times after evacuation at the end of this trip yesterday and got 42 45 49 48 44 38 43 33 46 45 33 33 33 33 33 32 33 33 33. Again this morning I checked it again after sitting overnight and I got 55 43 60 37 47 41 36 40 35 36 43 36 36 34 44 33 26 31 36 35. I did get 90 and 150 seconds before the junk yard part swap but nothing this high since.
At this point I think I have two options 1. master cylinder rebuild (will fix if there is an internal leak here) or 2. replace the booster/master assembly. Given comments prior "Test even with a leak will usually have about the same time ... to get 31 to 52 seconds indicates sometime else going on" it seems unlikely that the master rebuild is unlikely to fix things and that I need to bite the bullet and shell out the $$$ for the entire assembly. Any thoughts?
Not sure if this makes a difference but the service records from 7 years ago and 50K miles ago state BRAKE SERVICE ~|~CHECK AND ADVISE ABS LIGHT WAS ON ~|~ABS ACTUATOR IS NOE RESPONDING ~|~NEED TO REPLACED ABS ACTUATOR. It also states customer pay but does not list a part number. I don't know if Toyota did the repair or another shop. The Accumulator I removed did have some purple/pink marker writing on it that looked like what you would see on a junk yard part. I'm not sure what actually went down there. Probably is water under the bridge at this point.
Just wanted to throw this out there...
Had the double pump, soft pedal, spongy pedal issue (whatever you want to call it). Brought it to my local Toyota Dealership expecting them to tell me I need to replace a 2500$ part to fix it. Upon initial inspection, the tech suspected air in the brake lines. They also noticed that the fluid is really dark and dirty. So after the brake flush, my brake pedal is now strong and firm. No double pumping or spongy brake feeling. Pedal travel is so much better. They charged me 139$ for the Brake Flush.
Had the double pump, soft pedal, spongy pedal issue (whatever you want to call it). Brought it to my local Toyota Dealership expecting them to tell me I need to replace a 2500$ part to fix it. Upon initial inspection, the tech suspected air in the brake lines. They also noticed that the fluid is really dark and dirty. So after the brake flush, my brake pedal is now strong and firm. No double pumping or spongy brake feeling. Pedal travel is so much better. They charged me 139$ for the Brake Flush.
I wish my problem were that easy.... I've flushed/bleed 5xs complete with abs air bleeding through techstream but I'm still having issues ... however my issue isn't a spongy pedal so I'd for sure start with a brake flush/bleed if you have a mushy pedal...
Okay, I've read this thread in it's entirety, but I feel like I have two issues going on.
1. Spongy/Double Pump - I'm sure a new piston will fix this
2. I'm leaking brake fluid from under the Master Cylinder. - Will a new piston fix this or is there something else going on?
1. Spongy/Double Pump - I'm sure a new piston will fix this
2. I'm leaking brake fluid from under the Master Cylinder. - Will a new piston fix this or is there something else going on?
Sounds like you have a leak that might be getting air in the system causing the spongy breaks. I would try and identify where the leak is coming from first before anything else.
2001LC
SILVER Star
If leak is under brake master assembly in engine compartment, it's not likely the master cylinder seal. It's likely the reservoir has or is overfilled and fluid coming from cap. Read the instructions for topping on reservoir. Second spot could be grommets in bottom of reservoir, not common unless overfilled. Other spot(s) and you've issue that a qualified mechanic needs to look at and soon. If booster motor is coming on to often for long duration (due to leak), without pedal being depressed, you've a leak that needs addressing ASAP, or motor will burn up!
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uHu
Bridgeburner
If it's just under the line when pressurized, it is overfilled.
Leaking grommets is reported a few times on mud. Also check what damage the fluid has done below the reservoir/master, like corrosion on the booster motor power connection bolts.
When bleeding, you might have to activate the ABS in order to get all air out. Otherwise, it might be the piston seals. (Service kit)
2001LC
SILVER Star
Grommet(s) leak will not effect pedal. They just seal passages from reservoir to master. I suspect most grommet leaks are actually from overfilling and should stop leaking when correct level set.
Good test for leak(s), is to evacuate accumulator. Then time how long booster motor runs to refill accumulator and pressurize system. Spec is 30 to 40 seconds. More and you've a leak or air in system.
trdcorolla
SILVER Star
When it's pressurized it's probably 1/4" to 3/8" under the full line. If you have it at the full line right now when it's pressured, remove about 1/4 to 3/8 (with the car off). With the car still off, pump the pedal 40 times and set the level to max after the 40th pump.
It should say how to fill it on the cap...I think.
uHu
Bridgeburner
When the booster pressurizes the accumulator, it fills it up with some brake fluid. This will show as missing fluid in the reservoir, which is normal. In order to check the level, you have to let out all the pressure first, by pumping the brakes 40 times with the ignition off, which will return all the fluid to the reservoir.
- Thread starter
- #279
Clean underside of brake fluid, then with mirror or feel around for leak.
Check all the brake lines to MC and fittings to MC. East coast truck have had them rust through.
Check booster and accumulator for leaks.
Check all the brake lines to MC and fittings to MC. East coast truck have had them rust through.
Check booster and accumulator for leaks.
