Do The Brakes Set Codes When Flushing?

I am reading this topic with great interest. I looked at my brake fluid level and it is very close to the low mark with 38k miles. Not sure where the fluid went since my garage floor is spotless and no signs of leakage around brakes.

My question is, where should the brake level be and at what point in time should it be checked? Before cold start, after driving a while, something in between?

Should I add fluid if it is at the near the low level?

Thanks!

 

Make sure you are truly at the low mark. Take a close look at post #25 in the other brake fluid thread: http://priuschat.com/forums/gen-iii...rake-fluid-loss-brake-tsbs-3.html#post1400586

If you have any doubts, take a picture and post it here. If you are still under 3/36 warranty, it would be better to point this out to your servicing dealer that fluid appears low to you, rather than adding fluid on your own, so that if there is a real problem that gets worse over time, it will be covered.

 

Thanks Seilerts! I used a marker and took a picture. As you suspected I did not know where the MIN mark was located. It appears to be below the middle line, which I guess is normal.

When should fluid be added? At the MIN mark?

Thanks for the clarification.

 

Typically the reason brake fluid level drops in the reservoir is due to pads getting thinner: as they thin the caliper pistons need to move out further to stay in conctact, and greater volume of fluid is needed to fill the void behind the pistons.

Usual scenario is: pads near min thickness as fluid level nears min level in reservoir. If you replace the pads, pushing the pistons back in for clearance, the level should get back near the full level in the reservoir.

Regarding disabling of brake control, with the brake pedal dance I outlined above: I think it would still be very easy to trigger a code. If for example you change pads, pushing the pistons back for clearance with the new pads, you would want to keep brake control disabled for the first few depressions of the brakes after the change: the pushed back pistons will have excess travel for the first few applications of the brakes.

Just removing the lower caliper bolt, rotating it up and pulling the pads for a cleaning, you might be ok, might even not need to disable brake control, as long as you are very careful to not push the piston back.

Then I wonder if there's a possibility of the car starting one of it's impromptu pressuring events, such as when you open the driver's door: if the piston is out in the open would this pop it out? Maybe worthwhile putting a C-clamp over it, just snug, not tight enough to push it though.

All things considered, including the apparent longevity of Prius brakes, this just might be one to leave to the dealership.

 

I think the traction battery is off line unless you are in the Ready mode.

 

As long as you can pressurize the pedal ok, before you reconnect.

 

I read the brake fluid replacement procedure in the service manual last night. There are two ways to replace the brake fluid-- with techstream and without.

Without techstream, you just need to put the car in ECB invalid mode. Then the front brakes are bled conventionally. For the rears, you hold down the brake pedal for no more than 100 sec at a time while the pump pushes out the fluid for you.

Toyota also lists a procedure for replacing the inverter coolant without the scantool. I think it's obvious that Toyota made the Gen III far more service friendly than the Gen II.

MB860 ?