Brake Fluid types Opinions? (1 Viewer)

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

As @2001LC mentions, as your brake pads wear the brake pistons are pushed further out of the caliper bores. That extra space in the bores is filled with brake fluid, which drops the level in the reservoir. So after 30,000 miles you may have enough pad wear to drop the level. Of course it may have been underfilled or have a leak somewhere, but some drop in fluid level as the pads wear is part of the design of that system.
All good info thanks. I'll make sure I check it all over a bit closer once the temps warm up.
 
Sorry if this is de-railing the fluid type thread but it's sort of relevant
>> When topping off I noticed the reservoir has a bit of a wiggle. Is that normal? Is there anything that should be tightened? I haven't had the opportunity to look any closer so excuse me taking the lazy way out for this diagnosis.
 
Sorry if this is de-railing the fluid type thread but it's sort of relevant
>> When topping off I noticed the reservoir has a bit of a wiggle. Is that normal? Is there anything that should be tightened? I haven't had the opportunity to look any closer so excuse me taking the lazy way out for this diagnosis.
I believe that is normal, due to the grommets/seals where the bottom of the reservoir mounts.
 
Good to know. Thanks for chiming in everyone. Can't believe I didn't check the level sooner. It was so close to the min line so I doubt any damage was done, but it was sort of consistently happening the past winter or two, and I just figured it was a sticky ebrake or something. So I would just wiggle it and eventually the light would go off. Should have known to check fluid right away.
 
So is it not good to mix different brands and types of brake fluid?

Which fluids are recommended, other than the OE?
 
I just flushed a quart of this thru / into my front brake caliper passenger and driver side system today using the pedal method, and while carefully topping up as I went. The brake pedal feels little better now than before.

I have no idea how long the brake fluid was in my truck. I can see that my brake master assembly appears to be original and the truck now has 289,000 miles on it. I bought this LC100 with 261k on it. I flushed the rear about 6 months or so ago with Toyota oem when I was doing rear brakes.

when I eventually have to replace the expensive brake master assembly, which I hope I’ll get another 50,000 miles or more out of my original, and when that fails I plan to use OEM Brake fluid from Toyota for my new $1300.00+ assembly. I’m not really sure if it’s gonna make a difference what fluid I use. When I was a less experienced do-it-yourself mechanic I never cared about brake fluid and I never changed it and by luck 🍀 I never had any problems with the 10 different vehicles I’ve owned.
IMG_4177.jpeg
 
Last edited:
Staining inside the reservoir, can give clue to age. If toyota factory fill, it can last for 7 to 14 years (Depending on humidity, where operated) without much if any staining or darkening of fluid.

Staining of reservoir, may happen sooner, if any other brand brake fluid added (topping). Topping should not be needed, unless brake fluid removed. Removed like when, replacing pad and or rotors.

When topping or flushing. It's best to use same fluid that is in system. Post #8 of this thread. We find a Toyota TSB concerning a brake master seal recall. That clearly illustrates, not all DOT 3 the same. That using other than Toyota brake fluid damaged seals of some Toyota/lexus brake masters.

Flushing:
First step in flushing, is removing most all (95%) from reservoir. Leaving just a little (~5%) in bottom of reservoir. Is so we don't introduce air into system, which save time and fluid. But even if air introduced, we get out during the flush any way.

Second step is flushing accumulator. Which takes 2.5 to 3 bottles of Toyota brake fluid, half bottle at a time.

Third step, is flushing lines and "calipers". Which we've no air to bleed off, if none introduced. But even if we do introduce air, the procedure has bleed air off.

Note on caliper flushing:
The calipers hold X amount of fluid, X depending on how far pistons extended (pad wear). The fronts calipers hold the most fluid, with 4 pistons and extra passages to them. Compared to rears with one poston. The 2003 up, a tad more fluid with the introduction of larger front pistons.

To flush calipers, we must compress piston into caliper. While its bleeder open, forcing old fluid out bleeder. This is not done during the typical periodic fluid flush. But is done during those times, pads and or rotors replaced. For that reason, flushing ever 2 to 3 years and just before a brake job, is advisable!

More on brakes, can be found here.
 
When topping or flushing. It's best to use same fluid that is in system. Post #8 of this thread. We find a Toyota TSB concerning a brake master seal recall. That clearly illustrates, not all DOT 3 the same. That using other than Toyota brake fluid damaged seals of some Toyota/lexus brake masters.

Copy pasted from internet search.

"Prestone DOT 3 is a synthetic fluid with a higher dry boiling point than the DOT minimum standard. It also has a 50,000-mile fluid life, prevents overheating and brake fade, and protects against corrosion.


  • Compatibility
    Brake fluids can be mixed if the added fluid is a higher grade. DOT 3 brake fluid is compatible with DOT 4 brake fluid.


  • Recommendations
    Toyota recommends using Toyota-specific brake fluid because it's designed for the vehicle's specific needs. However, if you want to improve your brakes' performance, you can use a brake fluid with better specifications than the original."
Not saying I'm right, but this is probably what a lot of people do, like me, they do a quick search on the net and then run with it. I couldn't guarantee Toyota brake fluid was what was in my system to begin with anyway..
 
Last edited:
Copy pasted from internet search.

"Prestone DOT 3 is a synthetic fluid with a higher dry boiling point than the DOT minimum standard. It also has a 50,000-mile fluid life, prevents overheating and brake fade, and protects against corrosion.
Brake fluid, is more time sensitive than miles. So a manufacturer that states 50K miles, is BS marketing IMHO. Sinces one could drive all HWY and put 1 million miles in 5 years and baerly tap the brakes. Or all short hops with in the city driving only 10K miles in 5 years, of very active hard braking.

Even more important to life of brake fluid, than time (time to absorb moisture from the air). Is type of use. Active heavy use, like a rally car racer. Which actively & rapidly compressing brake fluid, Using the brakes, every few minutes and often hard braking. This bring fluid temp up high and fast. They need the higher boiling point fluid, then average driver. They also need to flush, after every race.

Whatever brake fluid is used. Flushing every 2 to 5 years, is best practice. No matter how many miles driven. We consider humidity and use, to help in timing of how many years. It fact I write the date on reservoir when last flushed, not the miles. Then watch color as my best indicator.
23-3-21 Brake res camber issue.jpeg


  • Compatibility
    Brake fluids can be mixed if the added fluid is a higher grade. DOT 3 brake fluid is compatible with DOT 4 brake fluid.


  • Recommendations
    Toyota recommends using Toyota-specific brake fluid because it's designed for the vehicle's specific needs.
Below is in post #8, which was taken from Toyota brake master recall notice TSB:

" During vehicle assembly, Toyota uses brake fluids containing polymers that act as lubricants for certain
brake system components. If replacement brake fluid is used that does not contain such polymers, or
contain only small amounts
, a part of the rubber seal (Brake Master Cylinder Cup) located at the rear of the
brake master cylinder may become dry, and the rubber seal may curl"

We learn from this TSB: Using off the shelf DOT II, III, IV brake fluid, can damage rubber seals in brake masters. That Toyota brake fluid, has a seal modifier/lub, which may not be found in other brake fluid.

In other words. We have the best chance of healthe seals, for the long run. Using Toyota brake fluid. We roll the dice with any other!


  • However, if you want to improve your brakes' performance, you can use a brake fluid with better specifications than the original."
^^^ Was this something you found Toyota put out? What does "better" mean^^^.

Just because it says DOT IV or the non silicone DOT 5.1 or 2 Doesn't mean better. IMHO the factory fill, is the best we've ever had in or likely will ever get, in the USA.


Not saying I'm right, but this is probably what a lot of people do, like me, they do a quick search on the net and then run with it. I couldn't guarantee Toyota brake fluid was what was in my system to begin with anyway..
There lies one big issue we face with a vehicle serviced by others. "Mixing fluids".
It's why we flush all fluids in a baseline. Even if Toyota/Lexus Dealerships maintained, we still don't actually know what was used.

Mixing fluid from different manufactures, is just not a good idea, no matter what a bottles states.
I can't tell how many Automatic Transmission (AT), brake system, gear boxes. Flushing out the old fluid, then replace 100% of a known fluid. Has improved performance, even corrected issue especially in AT.

Whereas Toyota did recommend, Toyota brake fluid or DOT 3 equivalent. It's the DOT 3 equivalent, that got Toyota in hot water. Resulting a in multi million dollar recall of brake master seals. The TSB on the recall was clear: Adding of non Toyota brake fluid, damaged seals in the master. That was not suppose to happen. Until it did, we all though all DOT 3 the same.

Additionally: If you look at brake fluid testers. You see they have different test lines for: DOT II, III, IV, etc and one specific for Toyota.

Additionally: I find system with factory fill and or only Toyota brake fluid used. Fluid, looks better for longer and so does reservoir (little to no staining).

Additionally: I found in my 01LC at ~12 year old, it still had factory fill. Color look near as good as new. I then flushed with Castrol Synthetic DOT 3&4. That Castrol brake fluid came out green from calipers, after only 3 years of use. The 98-02 brake calipers used copper banjo bolts and washers for flex line to caliper banjo. Copper turn green, in present of moisture. HUMM!

Here something I've found very interesting. When timing booster motor run time to fully charge/pressurize, after evacuating accumulator (key off, pump brake pedal forty times). The time is significantly decreased (in some) by using Toyota Brake fluid. Which Toyota states on bottle, is a heavy brake fluid special formulated for Toyota.

We can not buy the same as factory fill in the USA. But we can get a close second, by buying Toyota brake fluid in the bottle.

I use only Toyota brake fluid, these days. Not even, most Dealership use it. They use cheap bulk. Consider also: Toyota and Lexus have been replacing an unusually high number of brake master (all models), for paste ~5 or 7 years. HUMMM!
 
"" During vehicle assembly, Toyota uses brake fluids containing polymers that act as lubricants for certain
brake system components. If replacement brake fluid is used that does not contain such polymers, or
contain only small amounts
, a part of the rubber seal (Brake Master Cylinder Cup) located at the rear of the
brake master cylinder may become dry, and the rubber seal may curl""

I wouldn't mind flushing again and having just Toyota fluid in there for peace of mind. But I won't be doing that right away.

Simple Internet Search for all this stuff, see below, it's interesting. The clipping showing the Prestone values came from the NAPA website, and the Toyota information from just a general google search. I have no reason to believe either is false information.

Toyota Genuine Brake Fluid is a DOT 3 polyglycol brake fluid that contains the following ingredients:
  • Triethylene glycol monobutyl ether: 20–<30% weight
  • Diethylene glycol: 15–<25% weight
  • Triethylene glycol monomethyl ether borate ester: 5–20% weight
  • Polyethylene glycol monobutyl ether: 5–10% weight
  • Diethylene glycol monobutyl ether: <3% weight
  • Diethylene glycol monomethyl ether: <3% weight

HERE IS WHAT IS IN PRESTONE SYNTHETIC DOT 3 BRAKE FLUID. EXACT AMOUNTS ARE TRADE SECRET..
Screenshot 2024-10-13 at 7.56.58 PM.png

In general, anything that has glycol/ether in the name will break rubber down over time. If you were to search the definition for each one of these agents listed above, you'd find yourself having to look up more terms to lead to an understanding of what each one agent does, and trust me, you'd be VERY DEEP into the chemistry before you had an understanding of it all unless you are Steve Hawking. I'd rather just trust the Toyota fluid and move on.
 
Last edited:
The Valvoline Synthetic DOT 3/4 is all I run in everything I own. Best OTS fluid there is IMHO. Go down the BITOG rabit hole if you want.

I run it in enduro car's that have no right being on the road but are raced hard enough the rotors are glowing bright red, and it holds up well enough to give you a decent pedal.

71FDg7pVhSL._AC_UF894,1000_QL80_.jpg
 
The Valvoline Synthetic DOT 3/4 is all I run in everything I own. Best OTS fluid there is IMHO. Go down the BITOG rabit hole if you want.

I run it in enduro car's that have no right being on the road but are raced hard enough the rotors are glowing bright red, and it holds up well enough to give you a decent pedal.

View attachment 3749096
Have you run it long term in a 100 Land Cruiser??? If so how many miles?? Would love to know!😄
 
I also used the Valvoline for about 5 years, after using Castrol for about 3. Before that I used most any DOT 1, II or III.

But switched to Toyota brake fluid only. After wholesale Toyota parts department buddy, mention the unusually high number of brake master being purchase in Toyota USA system. I then stop in their shop, and asked: What brake fluid, they install. Master tech said bulk, unless upgrade on work order to BG ultra. Same master tech said he'd replace 6 master that week.

This got me to thinking about the old master recall, due to other than Toyota brake fluid used.

Since, I replace a fair number of brake master and done a tone of flushes. I decided to stop the brain damage, trying to find best fluid to use, and Just go with safest bet! Toyota brake fluid.
 
Last edited:
Yep.
 
Have you run it long term in a 100 Land Cruiser??? If so how many miles?? Would love to know!😄
I will be shortly!
Even though my 100 has decent looking fluid, a full exchange is on my list.

Apples to Oranges, but I've run the Valvoline 3/4 in quite a few Toyota's that I 100% assure you see way more braking action than any 100 series' on this site.
 
I will be shortly!
Even though my 100 has decent looking fluid, a full exchange is on my list.

Apples to Oranges, but I've run the Valvoline 3/4 in quite a few Toyota's that I 100% assure you see way more braking action than any 100 series' on this site.
The topic issue wasn't about performance, but premature rubber seal break down in the master brake assembly because of all fluids not being created equal. I'm personally probably going to flush out all my fluid and put in Toyota OEM after experiencing this thread. if for only peace of mind, I'm going to do that...
 
I wouldn't mind flushing again and having just Toyota fluid in there for peace of mind. But I won't be doing that right away.

Simple Internet Search for all this stuff, see below, it's interesting. The clipping showing the Prestone values came from the NAPA website, and the Toyota information from just a general google search. I have no reason to believe either is false information.

Toyota Genuine Brake Fluid is a DOT 3 polyglycol brake fluid that contains the following ingredients:
  • Triethylene glycol monobutyl ether: 20–<30% weight
  • Diethylene glycol: 15–<25% weight
  • Triethylene glycol monomethyl ether borate ester: 5–20% weight
  • Polyethylene glycol monobutyl ether: 5–10% weight
  • Diethylene glycol monobutyl ether: <3% weight
  • Diethylene glycol monomethyl ether: <3% weight

HERE IS WHAT IS IN PRESTONE SYNTHETIC DOT 3 BRAKE FLUID. EXACT AMOUNTS ARE TRADE SECRET..
View attachment 3749084
In general, anything that has glycol/ether in the name will break rubber down over time. If you were to search the definition for each one of these agents listed above, you'd find yourself having to look up more terms to lead to an understanding of what each one agent does, and trust me, you'd be VERY DEEP into the chemistry before you had an understanding of it all unless you are Steve Hawking. I'd rather just trust the Toyota fluid and move on.
I'm curious if they're purposely arriving at those percentages, or if that's just an analysis of the resulting fluid after whoever makes it for Toyota combines the alcohol and glycerine.
 
The topic issue wasn't about performance, but premature rubber seal break down in the master brake assembly because of all fluids not being created equal. I'm personally probably going to flush out all my fluid and put in Toyota OEM after experiencing this thread. if for only peace of mind, I'm going to do that...
I think I had too many wobble pops last night because I totally forgot about the issues with the seals in the booster.
Thinking about it, just like AHC fluid OEM is probably the way to go.
 
I wouldn't mind flushing again and having just Toyota fluid in there for peace of mind. But I won't be doing that right away.

Did u end up flushing the prestone out?

I did a complete flush, twice, 4 months ago and this morning i noticed the fluid looks greyish already.
I have another sealed 1L prestone bottle, I was thinking of another flush incase the new fluid already got contaminated with some sort of residues in the system after the first flush?!!
 

Users who are viewing this thread

Back
Top Bottom