Brake fluid exchange interval?

This is an excerpt from Toyota Canada 2014 Prius Warranty and Maintenance Guide:



In a nutshell, Toyota Canada's saying to change the brake fluid every 3 years or 30K miles, whichever comes first. They didn't use to say that; my (very convoluted) 2010 maintenance instruction makes no mention of brake fluid. And a few years later, I believe with the advent of 4th gen, they quit putting any sort of maintenance schedule in the booklet, made it all an online messterpiece...


If your're interested to DIY, see also the "brake fluid replacement" link in my signature.

 

What I have done a few times in a few of my power sports equipment which can be really difficult to bleed I take a syringe and I suck out the reservoir up in the front of the car completely dry then on the end of my hemostats I put a paper towel and I wipe out the jug usually it's very clean already and the brake fluid is almost water clear to a very light almost yellow I take my new dot 4 brake fluid or 5 as case may be. I fill up the reservoir and overfill it then I go to the furthest zerk fitting rear wheel left usually crack that and let it run till clear break fluid is falling on the rag I have laying under the wheel watching I can stand up and watch it whatever on the white paper towel I'll see when the dirt stops and then I go to each other wheel and do the same thing that way there I haven't broken the prime of the brake system and the dirt is carried right out as the new fluid pushes the old through the line and down some of these vehicles this may or may not work but generally it can be made to work.

 

One major issue with brake fluid is that it absorbs water from the air, which lowers the boiling point and promotes corrosion, neither good.

The humidity of the air where you live will be a better indicator of the interval than either time or miles. There are test strips which indicates if you need to bleed your brakes. ( It is nontrivial in a Prius, you may wish to have the dealer do it, they have the software recommended)

 

mine will be 10 years old in april

 

I'm using unsupported brake fluid from my power sports equipment I think it's more tool it doesn't ingest the moisture which is the good thing for me because I certainly don't like to be changing and messing with it once every 15 years 13 years or something

 

One of the most essential services in a Prius is the brake fluid change. Unfortunately, luck of maintenance is one of the main reasons for the frequent and extremely expensive actuator replacements.

 

I know you want the fluid to be super clean because in these actuator pump thingies it's just a boon for things to go wrong all the little tiny ways and places the fluid has to pump through but I guess that's why power sports equipment uses dot five fluid it doesn't take on moisture seems to work well and most of these ABS bikes and stuff that I have so I tried it in the Prius it seems to work well all the fluid and the Prius brake wise is water clear almost and the jug is perfectly clear no black no brown nothing nothing nothing like my older cars so we'll let it rip my 05 Prius was the same way fluid color consistency no water take fluid out drop it on metal look for the drops to separate nothing but it's break actuator pump failed solid pedal couldn't hardly move the car

 

if you never remove the reservoir cover, no problems

 

I remove it long enough to suck it down completely dry to where just that little hole where it feeds the system you see a little bit of the old fluid then I wipe out the jug with a dry paper towel then fill it up with dot five or the synthetic brake fluid notul goes in my motorcycle

 

Right. So, if you live in a dry climate, no need to change. In addition to the test strips mentioned above, there are cheap battery powered testers available from Amazon.

I'm in year 13 on the original fluid. The dealer here in Colorado has suggested all kinds of unnecessary stuff but never a brake fluid replacement. Of course, if it gives you peace of mind, do it.

 

Brake fluid should be checked not just blindly change just because we want it. Just like Tesla service interval about brake fluid. Replace only when necessary depends on how dark and % water contamination. Not base on mileage either.
If it is more than 2% or gets very dark, we change it. Otherwise, save our time although DOT3 fluid is cheaper than engine oil. Spend more money on oil change instead and prevent oil consumption in a long run.