Will the car maintain the 12V while in invalid mode?

When my mechanic changed my brake fluid I put the car in Invalid mode.
Changing fluid was a job for 8-10 minutes.
Voltage drop was 0.1V from 12.6V to 12.5V.

Of course, before putting in Invalid mode I shutdown AC/ventilation/interior lights/radio.

 

Depends on voltage

 

The brake bleeding procedure, especially the longer one that also bleeds the actuator, has a seqience that ends with fully emptying and repumping the accumulator, six times.

Even on a strong battery, by the time you get to that part of the procedure, the pump may end up sounding like a dying wind-up toy by the fifth or sixth repetition.

If I had a power supply around that I could keep attached to the battery while going through the procedure, that's what I'd probably do.

 

That's hopeless, not "weak".

What do you need Invalid Mode for? If it's a (relatively discretionary) brake fluid replacement, I would suggest replace the battery first, and get an appropriate charger (smart charger, one will run through a cycle and can be left on indefinitely), and have the charger hooked up when you do the invalid mode procedure.

For a complete, 4-corner brake fluid replacement, using non-Techstream method, I used 2 pints, Toyota DOT3.

 

No, just bleeding fluid out of the 4 corners. I followed the Repair Manual non-Techstream method in attached, with copious watching of @NutzAboutBolts. The only exception I took with the video was to follow the Repair Manual sequence. In a nutshell: you start at the front/right corner, then go counterclockwise. Next is front/left, then rear/left, and finally rear/right.

I basted out as much as practical from the reservoir at the outset, then topped up with fresh. I was careful not to let the reservoir level get crazy low, just in case...

I had a charger on the battery for the duration. I'd recommend deal with the battery issue first, and for extra safety, get a charger.

The last time around (done this twice now, 3 years apart) I missed a simple but crucial step, and could not get into Invalid Mode: the parking brake has to be on. Not sure why, but it does. Watch the video carefully, for the steps to get into that mode.

Read carefully the actions that can kick you out of invalid mode; you don't want to do that. A low battery might be one, not sure. One for sure is turning a wheel. Not sure why. But be careful.

Steps for me:

1. Raise the whole car and support on safety stands.*
2. Remove all 4 wheels.*
3. Put car iin Invalid Mode. (with charger connected). Check and note (maybe even mark) the level of fluid in the reservoir.
4. Baste out most of the reservoir fluid, refill with fresh. It'll take about a cup (1/2 of the first pint). (There's a strainer basket inside the reseroir, with just a narrow slit that allows you to reach further down. You want to have some sort of syringe with a very skinny longish spigot on the end. Again, don't go crazy low.)
5. Commencing with front/right. It's good to have a proper bleed bolt attachment pushed onto your drain hose. It's like a little ball socket: pushes on and locks. I typically break the bleed bolt slightly loose with a socket on ratchet, just for better control. Not enough that it's bleeding, just slightly loose. Push the attachement with hose onto the bolt, run the other end into a largish jar with a hole in the lid. No need to have brake fluid already in the jar I found. Note, @NutzAboutBolts using vacuum suction throughout, I found a simple tube into a jar worked fine.
6. Have an assistant sit in the driver's seat, pump the brake pedal a couple of times, then push continuously.
7. With a box wrench, crack open the bleed bolt, for just a split-second, then quickly shut it. With the fronts that's all you can do. Talk with the assistant, they'll be reporting their foot dropped to the floor very fast.
8. Repeat about 7~8 times, then go to left/front, do the same procedure. By now you should be getting into the second (last) pint.
9. Go to the left/rear corner and repeat. Except, here you can leave the bleed bolt open till the cows come home. The assistant pushing brake pedal will report it doesn't drop. I would suggest 3~4 somewhat protracted bleeds. Keep in mind you want to do all four, end up with a slight amount in reserve, for possible top up.
10. Repeat with right/rear. Worth noting: as you go, you regularly need to check fluid level in the reservoir, keep topping it up. You don't want it running dry. Aim to get to the end with a few tablespoons in reserve (just in case you want to fine tune level later), and the level where it was at the outset. I wouldn't save it long term though: if you don't need it I would add it to the drained, for recycling; it doesn't keep well. I think if you brought it to dealership service department they would recycle it for you.
11 Verify all bleed bolts are snugged up ok, and reinstall the protective caps, wheels back on, lower car, torque wheels.


* You can do the job with the car on the ground, but I think access is a lot easier with the car raised and wheels off.

 

The bleed screws are near top of caliper, with black rubber protective caps. A little more than 1/4" dia by maybe 3/8" high. You need 8mm and 10mm box wrenches for them.

 

Ahh. Yeah that's the protective cap, you have to twist and pull off. One end is 8mm size, the other 10mm. I forget which is which.

 

Finally managed to see all 3 pics. I would suggest try to just post directly in the thread btw; it's a pain with Imjur (ok on pc, but a hassle on Phone).

Yeah those are them. All should have caps, 2 are 10 mm and 2 are 8 mm (wrench size).

I would use proper bleed valve attachment too. Here's one example, the elbow shaped items:

Mityvac MVA6913 Brake Bleed Adapter Kit

 

Makes ECU think car might be in motion.

 

Hi Mendel, is it safe to set the car in invalid mode with the charger connected to the 12 battery? what I leant from my charger use instructions is never to swtich on the car power before disconnecting the charger. Another silly question is after comleting the rear brakes bleeding, can I switch off the car and do front brakes flush by depressing the brake pedal manually?

 

Curious to know - did you leave the charger connected and/or do the front brakes with the car off?