2008 Prius Hybrid Battery

[Nathan jones]

Originally Posted by Isaac Zachary

I tried for several months, even a year later. I just kind of gave up. The company that used to sell this particular one seems like they don't sell them anymore. It was almost 5 years ago, when I got the Avalon, when I also tried getting into Tech Stream.

So I don't attempt to fix the radio/infotainment center problems. I will have to take it to a dealer (again) to have it fixed.

When I change my brake fluid, I now reluctantly take it to a mechanic, which I hate doing since I've been scammed too many times by mechanics.

I may try it again one day. I don't know.

You don't need techstream to bleed the brakes, just two people. As in the old days one person with a spanner and bottle. Put the car in park. Have the person open the bolt, very slowly depress the brake until the pump starts, the fluid will be pumped. Close the bolt once air is out. It can be done on your own

https://www.youtube.com/watch?v=FKqxqgL2b4M

[Isaac Zachary]

Originally Posted by Nathan jones

You don't need techstream to bleed the brakes, just two people. As in the old days one person with a spanner and bottle. Put the car in park. Have the person open the bolt, very slowly depress the brake until the pump starts, the fluid will be pumped. Close the bolt once air is out. It can be done on your own

Interesting.

However, the guy making the video does mention that this method is "not as good" as using the scan tool.

It might get the fluid through all the ABS pump parts, but what about the parts that hold back fluid during regen?

[Piotrsko]

As long as one end of the drain tube stays attached to the zerk and the other remains submerged or you don't run out of fluid in the master, you can bleed brakes by yourself. I do it all the time. You're removing air from the fluid and replacing the old fluid with new.

[Isaac Zachary]

Originally Posted by Piotrsko

As long as one end of the drain tube stays attached to the zerk and the other remains submerged or you don't run out of fluid in the master, you can bleed brakes by yourself. I do it all the time. You're removing air from the fluid and replacing the old fluid with new.

I always replaced it myself in older vehicles. But newer ones have many fluid circuits, especially hybrids that not only have ABS and traction control circuits but also circuits that hold back fluid pressure during regen braking.

Just pumping the pedal and keeping air out is not enough anymore for actually replacing the brake fluid in the entire system because you have to have a tool to open the valves to each of those fluid circuits. Otherwise the new fluid just goes around the internal parts instead of through them.

[JSH]

Originally Posted by Isaac Zachary

Interesting.

However, the guy making the video does mention that this method is "not as good" as using the scan tool.

It might get the fluid through all the ABS pump parts, but what about the parts that hold back fluid during regen?

"Best" is to use a diagnostic / service tool to activate all the circuits to fully flush out the old brake fluid.

"Good Enough" is to manually bleed the brakes and replace 95% or so of the brake fluid. If you really want to get that last bit then after you bleed and replace the fluid then head out and do some full-on emergency stops to cycle the ABS to cycle new fluid through the ABS module. Then you can bleed the brakes again.

Personally, I do the manual bleed / replacement and then cycle the ABS and call it good. You will always have some residual brake fluid in the circuit unless you bleed / replace multiple times.

The purpose of replacing the brake fluid is two-fold.
A. Brake fluid absorbs water of time and that moisture can cause corrosion and can also boil at high temps and cause brake failure.
B. Old brake fluid will gum up the ABS module - especially for those that never activate the ABS and cycle fresh fluid through. The more complicated the ABS / stability control system the more important it is to replace the brake fluid as recommended in the service manual.

[S Keith]

For the 2008 Prius, I can't find a reference in either the owner's manual or the maintenance schedule that explicitly requires one to replace either the brake fluid or the transaxle fluid.

[JSH]

Originally Posted by S Keith

For the 2008 Prius, I can't find a reference in either the owner's manual or the maintenance schedule that explicitly requires one to replace either the brake fluid or the transaxle fluid.

That's odd. I don't have the original service schedule anymore but my spreadsheet of required maintenance I made from the 2005 / 2009 schedule says every 2 years.

My 2014 VW TDI also said every 2 years.

My 2017 Bolt is every 5 years - That is one of the few things it requires

If you don't want to go by time or schedule you can test the fluid and replace it at 2% water content. (Fresh DOT 3 boils at 401F. With 3% moisture that drops to 293F)

[Isaac Zachary]

Originally Posted by JSH

The purpose of replacing the brake fluid is two-fold.
A. Brake fluid absorbs water of time and that moisture can cause corrosion and can also boil at high temps and cause brake failure.
B. Old brake fluid will gum up the ABS module - especially for those that never activate the ABS and cycle fresh fluid through. The more complicated the ABS / stability control system the more important it is to replace the brake fluid as recommended in the service manual.

Yep!

And with brake actuator module replacements costing sometimes over $2,000 on hybrids and EV's, I'd rather just change the fluid periodically from time to time instead of gumming it up or corroding it.

[Isaac Zachary]

Originally Posted by S Keith

For the 2008 Prius, I can't find a reference in either the owner's manual or the maintenance schedule that explicitly requires one to replace either the brake fluid or the transaxle fluid.

I can't find any brake fluid change recommendations on most any Toyota either.

But with transaxle fluid changes, my manual (2006, as well as the Avalon hybrid) say every 60,000 miles, so I do it ever 60,000 miles (which has been twice so far).

[redpoint5]

Dang, and here I've just been replacing brake fluid when I replace pads, which is like once in my term of ownership.

I don't think I've ever gone through a new set of pads on any vehicle. It's always me replacing used pads with ceramics, and never again.

Perhaps the truck. I'm sure I've done multiple pads, and a caliper, and rotors, on the truck.

Twice a decade seems right to me. I'll have to check water content next time I flush brakes.