Adding Brake Fluid to Prius two

Was the car new when you purchased, with full pad thickness, when the level was already low?

 

Maybe it was underfilled, from the factory. If you're getting any maintenance done at the dealership maybe ask their opinion, and they could top it up, save you buying a bottle of the fluid.

I don't think you'd want to top up to the full mark, keep it a little lower, considering there'll have been some reduction in the pad thickness.

OTOH, it's not the end of the world if you do overfill a bit, I mean: you can baste out some when it comes time for new pads. All in all, it seems odd: ours was on the full mark when purchased new, and has dropped a bit I think. Our pad thickness are reducing a bit too, to around 7 mm remaining, at almost 50000 km's. New is 10.0 on front, 9.5 on rear.

If it's just dropped slightly over 30000 miles, sounds like no leaks, anyway.

 

Apparently you don't have a good understanding or you would be inspecting the pads first.
If the pads do need to be replaced soon, then adding fluid is just a waste of time.

 

I had the same issue 10k into the car. i Never thought about checking it, and it was low. I took it to the dealer, and they inspected it and found no leaks in the system, so they topped it off. Now at 34k it is low again, and the dealer says it is normal in these vehicles with the braking system they have. So i never kept arguing with them since it is my first prius and am still learning about Prius noises and fluid levels

 

Second time around it might be low pads. Have you been keeping an eye on their thickness.

 

Not really, but shouldn't it be a any normal car? Should make a squeaky noise when pads are on their last leg no?

 

When you're at the dealership next time, you could ask specifically about pad thickness. Any time they've got the wheels off for rotation it's relatively easy to eyeball. That might clear up why the fluid's dropping: there's a direct correlation between pad thickness and fluid level in the reservoir. Or there should be, unless it's disappearing elsewhere.

What sounds a little fishy: you report dropping fluid level to them, and their response is it's normal. They're supposed to be doing (cursory) brake inspections if you're getting maintenance there, pretty much every other interval. The feel I get is that a lot of places are doing zip, just relying on Toyota's over-engineering, ignoring the system until there's a complaint.

Again, my guess is that you're pad thickness's have gone down a bit, but good to know. Minimum thickness is 1 mm, but: brakes don't wear evenly, and going down to 1 mm is asking for trouble. It's good to be cognisant of where they're at, plan ahead.

 

You did an excellent job there.........of ignoring the important points and replying to the insignificant ones.

If you do this, given all that you have said, it is likely you will muck something up.
Just my opinion, of course.

 

Just to make sure everyone is on the same page...

The brake fluid level in the reservoir will vary with the amount of fluid in the brake accumulator.

The Max level is the brake fluid level in the reservoir when the accumulator is completely discharged.
You would almost never see this in normal use. If you wanted to discharge the accumulator, an easy way is to disconnect the 12v battery, and then pump the brake pedal up to 40 times. Somewhere between the 20th and 40th pump, the brake pedal will become very firm. This is when the accumulator is discharged.

The Support Level is the max fluid level with the accumulator fully charged.
When you first open the driver's door, the brake hydraulic pump runs, drawing fluid from the reservoir and pressurizing the accumulator, preparing the brake system for driving.
Pump the brake pedal a few times, the pump will run and then stop. Check the brake fluid level. It should be near the Support Level.

The Min level is below the seam of the reservoir. If your brake fluid is near the Min level, the Red Brake Warning Light would remain ON anytime the vehicle is in Ignition ON or Ready mode.
If your brake fluid is near the Min level, the brake system will require inspection.

 

Interesting. I opened passenger door, reached across to release hood latch, then took this pic:



Then opened driver's door, let the sounds subside, and took a second pic: