Brake fluid exchange or hybrid WS transmission drain and fill?
Both seem like they matter. I want to do one now and the other later for several reasons. Let’s say I can only pick one for now. What would you choose?
2015 Prius with 60k miles.
Brake fluid.
You’re supposed to change brake fluid every 2 years. Transmission fluid is listed as lasting the whole life of the car, usually around 150k–200k miles.
In the Prius, brake fluid doesn’t last as long. The ABS system can fail, and changing the fluid can help it last longer.
Transmission fluid in these cars doesn’t break down fast. These transmissions are simple and almost never fail.
@Chambers
I’ve seen more brake failures caused by not changing fluid than transmission failures. I’d say do the brake fluid first.
Mikel said:
@Chambers
I’ve seen more brake failures caused by not changing fluid than transmission failures. I’d say do the brake fluid first.
My brakes are still working well at 360k miles. I’ve changed the brake fluid several times and it’s paid off.
@Chambers
This person definitely knows how to stop.
@Chambers
Good point, but transmission fluid is easy to change at home and doesn’t cost much. I did it faster than an oil change. I think it’s better to replace it than rely on the idea of “lifetime” fluid.
@Vinnie
It’s about $67 for 4 quarts of the right Toyota ATF fluid. I wouldn’t mix fluids since you can’t drain it all at once.
This Prius transmission is a single-speed design. Hardly anything wears out in there. People rarely change the fluid and still don’t have trouble. I still do it every 100k miles or so. When I’ve done early changes, the fluid still looked clean.
Brake fluid is more urgent on hybrids. Because the brakes don’t heat up much (thanks to regenerative braking), moisture doesn’t boil out and can damage the ABS.
If I had to pick one first, I’d go with brake fluid. Old fluid can rust the lines. I’ve kept mine clean and I’m still on the original ABS at 360k miles, and my car is one of the ones Toyota covered under a brake warranty.
@Chambers
I just changed my transmission fluid at 260k miles. It was really dirty and the magnet bolt had a lot of metal bits. Not sure if the last owner ever changed it. Still, I agree—do the brakes first.
@Unclewaffl3s
Yeah, I did mine at 130k and it looked bad. When I changed it between 50k–70k, it was still clean. I think 75k–100k is a good time to change it.
The transmission isn’t something you usually have to worry about in these cars. That’s part of what makes them last.
Honestly, at 60k miles, I don’t think either one is urgent right now.
Adley said:
Honestly, at 60k miles, I don’t think either one is urgent right now.
Neither is part of Toyota’s standard maintenance list.
Brake fluid isn’t even mentioned.
Transmission fluid only gets mentioned for cars that tow or get driven really hard. And Prius uses a much simpler transmission than gas cars, and they almost never fail.
Brake fluid—only if they flush it with a scanner. A lot of old fluid gets stuck in the regenerative braking system, and that part only gets flushed with a tool. If they just pump and bleed, you’re only getting part of the old fluid out.
If they can’t do that, then I’d say transmission fluid. I’ve done both. Transmission fluid is easy with basic tools and a fluid pump. You’ll need a jack though. If you already have the tools, the fluid cost me about $50.
I’d go with the transmission service.
robertson said:
I’d go with the transmission service.
I wouldn’t. I’ve seen way more brake actuator failures than transmission problems.
robertson said:
I’d go with the transmission service.
I wouldn’t. I’ve seen way more brake actuator failures than transmission problems.
Does bad brake fluid actually cause actuator failures? I always wondered what exactly fails in the actuator system.