Drain and Fill Brake Fluid Reservoir, Fruitless or Genius? LC100 (1 Viewer)

[Les Summer]

I want to ask, if I were to suction out all of the brake fluid (Toyota DOT3: 00475-1BF03) from the reservoir of my 100LC, does the new fluid that I put in eventually cycle through the whole brake system? Could doing this a few times be the lazy man's way to incorporate new brake fluid without ever having to take a knee?

I recently have had great success doing this through the transmission dipstick hole, and eventually replacing all of my transmission fluid without ever having to get under the truck, so I was wondering if the same principle will apply to the brake system. Thanks.

 

[katit]

No it won’t. Fluid doesn’t circulate, need to blead

 

[Les Summer]

No it won’t. Fluid doesn’t circulate, need to blead

I should have guessed. Thanks.

 

[OEMGUY0720]

Brake fluid moves on the principle of gravity. Drain, refill, bleed and repeat. Start the bleed the closest first and farthest last from the brake booster.

 

[Trunk Monkey]

Other way around, furthest first, closest last. You can replace the brake fluid to a degree doing what you're talking about (search for the turkey baster method) and it will clean it up somewhat, but the ideal way is to fully drain.

 

[TheForger]

Keep in mind it's very difficult to suck out all the brake fluid from the reservoir with the filter in there. You may get half if you're lucky

 

[hoser]

@OEMGUY0720 @Trunk Monkey
I’ve always done furthest first but my ‘98 FSM says to do the front first, then rear.

Could be an error, haven’t given it much thought actually. What do other years say? What does a RHD drive FSM say?

 

[medtro]

Keep in mind it's very difficult to suck out all the brake fluid from the reservoir with the filter in there. You may get half if you're lucky

This can get most of the fluid out with the black tip on the hose removed.

 

[2001LC]

Only one good way to clear/clean out the reservoir tank; With IG key ON, hold down brake pedal, open a rear caliper bleeder.

Once reservoir very near the bottom. Close bleeder, turn off IG key then pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.
After above flush, keep reservoir above low line at all times.
Now move to other rear, for a short flush of its line/caliper.

Now move to FL, pump pedal 20 times IG key on. IG key now stay on until done.
Hold down pedal and open FL bleeder. Close bleeder and then pump pedal 5 times. Repeat 10 times. Only needing to pump pedal 5 times between each bleed., after the first 20 pump.
Never release brake pedal until bleeder closed, or air is suck in to caliper.

Now move to FR (front right). Bleed it, a minimum of 7 times.

Torque bleeders to 9 to 11ft-lbf. Blow out bleeder with brake clean (straw) than add WD-40 (w/straw) and cap them.

I use a minimum of 5 Toyota bottles, maximum 7 bottles. How many bottles depends on how much used to flush accumulator, the more the better. Also if caliper piston clasped, to get max out of calipers.

 

[ed94r]

Only one good way to clear/clean out the reservoir tank; With IG key ON, hold down brake pedal, open a rear caliper bleeder.

View attachment 3404255
Once reservoir very near the bottom. Close bleeder, IG key OFF, pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.
After this keep reservoir above low line at all times.
Than move to other rear, for a short flush of its line/caliper.
View attachment 3404256

Now move to FL, pump pedal 20 IG key on. IG key now stay on until done.
Hold down pedal and open FL bleeder. Close bleeder and then pump pedal 5 times. Repeat 10 times. Only needing to pump pedal 5 times between each bleed.
Never release brake pedal until bleeder closed, or air is suck in to caliper.

Now move to FR (front right). Bleed it, a minimum of 7 times.

Torque bleeders to 9 to 11ft-lbf. Blow out bleeder with brake clean (straw) than add WD-40 (w/straw) and cap them.

^^^Do you do this without techstream?

Also, how many people do you need to do this process...at least 2?

Thanks!!

 

[Dirt J]

Which brake line is the shortest length from the reservoir to the bleeder? Draining the reservoir using that line would get the old fluid out of the reservoir via the most direct route. Less brake line for old fluid to travel through.

 

[katit]

And which fluid and how much do we need for full flush?

 

[ClassyJalopy]

Which brake line is the shortest length from the reservoir to the bleeder? Draining the reservoir using that line would get the old fluid out of the reservoir via the most direct route. Less brake line for old fluid to travel through.

Driver side front!

 

[T4R2TLC]

Which brake line is the shortest length from the reservoir to the bleeder? Draining the reservoir using that line would get the old fluid out of the reservoir via the most direct route. Less brake line for old fluid to travel through.

Drivers front is shortest by distance, but the rear calipers bleed so much faster (can bleed continually rather than press-release method) that I have used rears as the initial drain point. The fronts are then quick and easy to do with a second person using press-release-repeat.

 

[ed94r]

Only one good way to clear/clean out the reservoir tank; With IG key ON, hold down brake pedal, open a rear caliper bleeder.

View attachment 3404255
Once reservoir very near the bottom. Close bleeder, IG key OFF, pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.
After this keep reservoir above low line at all times.
Than move to other rear, for a short flush of its line/caliper.
View attachment 3404256

Now move to FL, pump pedal 20 IG key on. IG key now stay on until done.
Hold down pedal and open FL bleeder. Close bleeder and then pump pedal 5 times. Repeat 10 times. Only needing to pump pedal 5 times between each bleed.
Never release brake pedal until bleeder closed, or air is suck in to caliper.

Now move to FR (front right). Bleed it, a minimum of 7 times.

Torque bleeders to 9 to 11ft-lbf. Blow out bleeder with brake clean (straw) than add WD-40 (w/straw) and cap them.

PM sent. I re-typed your work instructions to be (in my mind) more clear. Can you review and I'll post?

 

[TexLexican]

Drivers front is shortest by distance, but the rear calipers bleed so much faster (can bleed continually rather than press-release method) that I have used rears as the initial drain point. The fronts are then quick and easy to do with a second person using press-release-repeat.

What do you mean continually? Open bleeder and let gravity do the work?

 

[T4R2TLC]

What do you mean continually? Open bleeder and let gravity do the work?

I don't know if it is gravity per se, as you need to keep the pedal depressed and you can hear the brake booster motor running.

What I mean is that when I bleed front brakes on my 100 or other vehicles with a similar HBB (late 3rd gen 4runner, LS430, etc) I bleed the fronts the 'conventional' way that I would bleed vacuum boosted brakes: pump pedal three times, hold pedal in depressed position, crack bleeder for 3 seconds or so, close bleeder, repeat. If the bleeder is kept open, the pressurized stream of fluid only lasts about 5 seconds. After those 5 or so seconds, the stream is slow which makes me think it would be inefficient and risk air entering the system if I were to leave the bleeder open to drain.

When I bleed the rears on my 100, I simply depress the pedal (can even use a bar, brick, whatever—as there is no pumping or releasing of pedal required), open the bleeder, and the brake booster will pump out fluid as quickly as the bleeder valve can handle. When the reservoir runs low or the fluid runs clear, I close the bleeder valve and add fluid to the reservoir. The fluid remains pressurized so long as there's fluid in the reservoir and the HBB pump motor is running.

It would take me dozens of pump 3x, hold, open bleeder, close bleeder, pump 'er back up cycles to drain the reservoir completely, it takes far less time, effort, and helping hands to drain the reservoir via the never-ending fluid pressure at the rear calipers. I do not know the true reasoning behind this, but I suspect it has less to do with gravity and more to do with how the ABS circuits are designed, but who am I to guess! If you want to gravity bleed or use a power bleeder, then yes the shorter line run of the fronts would likely be preferred and you would not rely on the HBB motor and pump to do the work for you.

 

[baltistyle]

Only one good way to clear/clean out the reservoir tank; With IG key ON, hold down brake pedal, open a rear caliper bleeder.

View attachment 3404255
Once reservoir very near the bottom. Close bleeder, IG key OFF, pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.
After this keep reservoir above low line at all times.
Than move to other rear, for a short flush of its line/caliper.
View attachment 3404256

Now move to FL, pump pedal 20 IG key on. IG key now stay on until done.
Hold down pedal and open FL bleeder. Close bleeder and then pump pedal 5 times. Repeat 10 times. Only needing to pump pedal 5 times between each bleed.
Never release brake pedal until bleeder closed, or air is suck in to caliper.

Now move to FR (front right). Bleed it, a minimum of 7 times.

Torque bleeders to 9 to 11ft-lbf. Blow out bleeder with brake clean (straw) than add WD-40 (w/straw) and cap them.

This is the only way to do it properly and is basically how it’s listed in the service manual. Doing it this way, the fluid is pumped by the car out through the line. The number of times for the pumping of the brake (40) is to activate the pump.

This way is very very fast and easy and it takes under ten minutes with two people. Doing it this way, as long as you don’t pull in air, the abs system does not need tech stream activation.

 

[2001LC]

^^^Do you do this without techstream?

Also, how many people do you need to do this process...at least 2?

Thanks!!

Sometimes yes sometimes no. With new brake master install, I'm more inclined to use tech stream. But just drive ~35 MPH on a dirt, wet or ice road. Then slam on brakes hard, to activate ABS. Do so 3 or 4 times.. Tech stream or driving. Both are open the valve in ABS (black box on side of master), allowing fluid to pass through.

I do the rears with my "little helper"
Fronts are better to have a second person to help.


"My Little helper" is a spring loaded shower curtain pole. Works very well for rear. Since rears continuously flows, as long as brake pedal held down and IG key ON (booster pump running). My little helper, can be used for front also. But requires getting out from under vehicle about 17 times, to pump pedal five time and reset it holding down the pedal between each bleed. Note: booster pressure does not work to continuously flow fluid out front bleeders, as pedal held down.

Which brake line is the shortest length from the reservoir to the bleeder? Draining the reservoir using that line would get the old fluid out of the reservoir via the most direct route. Less brake line for old fluid to travel through.

FL is shortest. But would take pumping and holding brake pedal about 70 times to clear reservoir

And which fluid and how much do we need for full flush?

I use only Toyota brake fluid. Not even Toyota or Lexus shop do that, they use bulk. But according to my people in parts department. Toyota and Lexus, are see an unussaly high number of master replaced. Could be why the price of master came down. High volume produce cycle!


Seem everyone has forgotten the TSB and brake master recall, due to using off the shelve brake fluid.

Keep in mind it's very difficult to suck out all the brake fluid from the reservoir with the filter in there. You may get half if you're lucky

You may find these interesting:

Brakes ...... Overdue write-up.

First and foremost: Brakes should only be worked by those, with high level of mechanical abilities and experienced with brake systems. With the age of all 100 series today, in our aging fleet. Any issue, with brake master assembly. IMHO, best and safest course of action. Have the whole brake...

forum.ih8mud.com

 

[Dirt J]

What are the final cut open reservoir pics showing?