Prius front discs and pads replacement

Any time's good, lol.

And when you're done, push the brake pedal multiple times, firm up the pedal. I'm not 100% sure how important that is, but it worked for me. What you don't want to happen is for the car to detect excessive pedal travel, freak out.

The front piston is plastic (resin, in Toyota speak), so be careful pushing it in: use a nice uniform contact, no point loads. Say a plywood scrap over the whole piston rim and a C-clamp.

Also, if you ever are working on the rears, be sure to get the pin on back of inner pad in between piston spokes pattern, firm up the pedal to get it seated, and only then reconnect battery. Maybe even go for test drive, and only afterwards apply parking brake, if you want. You want that pin well seated, or the rear brakes will drag.

 

I would suggest propping the hatch open before you unplug the battery you wont be able to open it with no power,
when I was done with my pads and rotors, I couldnt open the hatch and had to climb in through the back door to get at the battery terminals.

 

A pair of heavy gloves is good: isolate the neg cable by stuffing it into one glove, lay the other glove across the hatch latch mechanism.

 

You might be ok, as long as you don't open driver's door. You want to avoid the system pressurizing while the caliper is pulled off. So 12 volt disconnect is just to really ensure no surprises.

Also, before reconnect of 12 volt: pump brake pedal, you don't want the system detecting excess pedal travel, setting a code.

 

Great advice. If you don't want to disconnect the power, just don't open the driver's door for any reason. When I had to fix a broken lug bolt, i just made sure I didn't open the door. There probably also is a way to keep the sensor in the door that trips the system on disconnected. I'm sure someone in here has done it.

 

You can clamp it. Mimic a shut door. I prefer battery disconnect tho, the thought of somehow blowing out a piston scares me into belts and braces tactics.

 

If you hang around your car for a few minutes after parking and powering off, you will notice it does a brake self-test all on its own around that time, whether you've opened the door or not. You wouldn't want to have the caliper unsecured for that (and especially not to have any fingers in it). I don't know whether that is the only time it ever self-tests on its own.

Disconnecting the power also allows you to get a true reading of the brake fluid level. With the power off, just cycle the brake pedal until it abruptly goes from easy-to-press to rocklike-hard (may take a couple dozen strokes or more). This returns all the brake fluid stored in the pressure accumulator back to the reservoir, in case you want to read the level.

If you have Techstream, you can accomplish the same thing with the "zero down" utility.

-Chap