Hello, I have never had my brake fluid replaced and I’m at 145k miles now. I’ve always gone based on the color but now I know that is not accurate at all. My main question is what should I ask for at the dealership? Like a full brake fluid flush or just a drain and fill. I don’t want them to do the most expensive thing but I also don’t want them to think I just want my master cylinder fluid replaced either.
Brake fluid flush. That does the most good especially on your highly complex master cylinder which allows regen in a hybrid. Should not be much more than $125.
Attached is an excerpt from the Toyota Canada 2014 Prius "Owner's Manual Supplement", which summarizes the maintenance schedule up here. The call it (sensibly) "Brake Fluid Replacement". Noteworthy: while Toyota USA says nothing about brake fluid replacement, Toyota Canada recommends to replace it tri-yearly or 48K kms (30K miles), whichever comes first (see attachment). I'll also attach Techstream and non-Techstream Repair Manual instructions, in case you're interested in the technical side. I've DIY'd the non-Techstream method twice. For a dealership with all the right tools, this should not take more than an hour. I used 2 pints of Toyota DOT3 fluid, which runs around $7~8 CDN apiece up through parts dept.
What's your take on using DOT 4 or 5.1 instead especially for places with a hot and humid climate since both have a higher dry and wet boiling points than DOT 3?
DOT 4 and 5.1 have a higher boiling point than 3. All are compatible with each other. 5.0 is silicone based, and is NOT compatible. I would use what Toyota recommends. The Prius does not put a lot of stress on the brakes.
Well, the Prius might be designed well enough not to put a lot of stress on the brakes but for countries with really slow and heavy traffic, you need to press on the brake pedals quite literally A LOT. I am hearing a significant number of ABS issues, Brake Pump and Booster failures etc. where I live.
Brake fluid absorb moisture. It’s really worth replacing at least few times during car lifecycle regardless of how the brakes are used
So if I'm understanding correctly, it can't be done like a traditional car when bleeding the brakes, probably because the regen system, right?
There is a procedure you start off with a scan tool when bleeding is needed. It opens the right computer-controlled valves in the brake actuator so all the bubbles get out. If all you are doing is brake fluid replacement—there are already no bubbles, and you'll be careful not to let any in, just new fluid—there is a non-scantool "replace brake fluid" procedure for that. Just remember that "brake fluid replacement" ≠ "brake bleeding". If there are bubbles to get out, use a scan tool and the bleed procedure.
See the “brake fluid replacement” link in my signature (on a phone turn it landscape to see signatures).
