Brake Fluid - is there a consensus on this?

[Skruf]

Read through a heap of thread and seems like opinion is split.

Somme say Dot 4 and 5 will destroy your system. Some say its no problem.

It is necessary to get genuine Dot 3?

 

[beatle_bayly]

DOT5 is silicone based. Dot 5.1, DOT4 and DOT3 are glycol ether products.

DOT3 to DOT5.1 are mixable and have higher thermal tolerance the higher the number.

DOT5 doesn't mix with water and to use it you really should completely overhaul the brake system. At the very least the system should be flushed completely with alcohol and purged dry.

I've never had an issue sourcing DOT3, but no reason you can't do a full bleed and replace with DOT4.

 

[excessive]

I use Valvoline Synthetic Dot3/4 available at Advance auto and many others. Been using this for years with good results.

 

[2001LC]

I use and recommended only Toyota brake fluid. IMHO it has seal conditioners and is a heavy fluid, that sets it apart from others.
Also IMHO: Mixing fluid is never good. Gone are the days when all DOT I, II or III are the same.

Case in point:
I just had a case, where booster motor run time was very high (charge accumulator). The time after pumping brake pedal 40 times IG key off, was 39 sec with battery at 12.65Volt. The color of the fluid, was actually good (near clear). Indicating fluid had not been in long and had a low moisture content.

I flushed the system, using Toyota brake fluid. Doing my usual 5 time flush of accumulator. I watched very close for any signs of any air in system as I flushed. Not one air bubble came out at any time.

Since fluid good, no air and voltage good. It "seem" the accumulator was past useful life and or AMPs to motor low (high resistance)

Once system completely flushed with new Toyota brake fluid. booster motor run time to charge, drop to 32 seconds.

 

[Jack90210]

I use and recommended only Toyota brake fluid. IMHO it has seal conditioners and is a heavy fluid, that sets it apart from others.
Also IMHO: Mixing fluid is never good. Gone are the days when all DOT I, II or III are the same.

Case in point:
I just had a case, where booster motor run time was very high (charge accumulator). The time after pump brake pedal 40 times IG key off, was 39 sec with battery at 12.65Volt. The color of the fluid, was actually good (near clear). Indicating fluid had not been in long and had a low moisture content.

I flushed the system, using Toyota brake fluid. Doing my usual 5 time flush of accumulator. I watched very close for any signs of any air in system as I flushed. Not one air bubble came out at any time.

Since fluid good, no air and voltage good. It "seem" the accumulator was past useful life and or AMPs to motor low (high resistance)

Once system completely flushed with new Toyota brake fluid. booster motor run time to charge, drop to 32 seconds.

Well that's actually very interesting! I wonder if it was the multiple flushes/booster actuation, or the fluid itself.

 

[Jack90210]

I use Valvoline Synthetic Dot3/4 available at Advance auto and many others. Been using this for years with good results.


View attachment 3553970

I've been using this fluid for over ten years in my LX myself. Zero problems. I flush the entire system annually.

That being said, I have carefully considered what @2001LC has to say about the use of OEM fluid; I suspect that the OEM stuff has a more robust additive package that holds up better over time (i.e. with a 3-year or longer flush interval).

 

[nissanh]

The prestone is what I've been using in past 20+ years and no issue either. I do a flush every 5-7 years. A brand new booster pump/master pump setup runs about 24 seconds.

 

[take123]

I'm sure OEM has more additives and is better. I personally use Prestone (the yellow one) 32oz DOT3 bottles for $6 each from LOWE's (cheapest place I found it). Have been using it so far, no issue.

Get two of these and it's good for a flush. I aim to flush it out every year. Keep a spare in the car if going away far.

https://www.lowes.com/pd/Prestone-DOT-3-Brake-Fluid/1002647598

 

[2001LC]

Well that's actually very interesting! I wonder if it was the multiple flushes/booster actuation, or the fluid itself.

No! The accumulator dumps into reservoir. So even in we do not flush accumulator 5 times, it does so over time anyway.
I do it 5 times, to get as much, old fluid out of system as I can. That way, if new fluid darkens quickly. I know it's not from old remains in accumulator. This is important, to get a glue as to health of seals of master and condition of screens in ABS unit.

Flushing regularly is the most important. Procedure and what we use to do so, is second.

I too, once though all DOT III the same. A Toyota shop foreman said to me he thought the same, until a brake master recall of 05-07 models and related TSB. At that time I elected to use a top name off the shelve DOT 3 (Castrol). It was to flush-out the factory fill from my 2001, at ~8 year old (~2009). The factory fluid came out looking as clear as new, for which I was amazed at how good it look. 3 yrs latar, I flushed out the off the shelve brake fluid. It came out green from the calipers. 98-02 have a copper banjo bolt and washers. Copper turns green in presence of moisture. Older Toyota fluid clear after more than 8 yrs, non Toyota green in 3 yrs Hummm!

Than in ~2021. A W/S parts department friend, at Toyota. Told me, they're seeing unusually high number of master being sold, nationally. About that time, all our master became available and prices drop by ~$1k. Humm!

Use whatever you like. I flush more fluid through than most and I use only Toyota fluid. Cost maybe $20 or $30 more per flush.

Use whatever you like. I use only Toyota!

 

[medtro]

Use whatever you like. I flush more fluid through than most and I use only Toyota fluid. Cost maybe $20 or $30 more per flush.

How much brake fluid did you use in a typical flush? Not a yearly maintenance flush.

 

[2001LC]

How much brake fluid did you use in a typical flush? Not a yearly maintenance flush.

It depends:

It can be done with 5. But I like 7 bottles on hand.
I may be installing a new master. Or I may come back around, with tech-stream ABS air bleed (mostly with new master). Or in old master, I flush accumulator with 2.5 to 3 bottles. If collapsing pistons in caliper and brake rotor/pads not new. Any of these, I may crack open a 7th bottle.