Replacing brake fluid and bleeding brakes on a GEN II Prius without Techstream

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by zak.kapoor, May 3, 2015.

  1. zak.kapoor

    zak.kapoor Junior Member

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    My 2008 Prius recently crossed 90K miles. It is running great and the brakes work fine. They are just not as sharp as before. The best way to describe it is that brakes felt spongy. Talking to friends and a quick web search pointed to the moisture in the brake fluid as the most likely cause for the problem. A few oil changes back the technician had also run a test on the brake fluid and mentioned that it had 2% moisture and needed to be replaced. I did not get it done at that time because I was not comfortable trusting a technician at a discount oil change shop with the Prius brakes.

    After doing some research and reading the Toyota service manual I was ready for the job. I finally completed the job today and it was a success. The process I used has been described in pieces in several posts. This is my attempt to put all this information together. I wish I had taken some pictures.

    Before I describe the process, I am assuming the reader has the following background:

    1. Knowledge of the front and back center jack points and the associated safety precautions. While working on the brakes you will not be able to drive the car so ramps may not be a viable option. Always make sure the wheel on the ground is blocked from moving forward or backward. Also the car needs to be resting on two jack stands and not on the jack only.

    2. Knowledge of the bleeding process. It is not as scary as it sounds. You just need to make sure the brake fluid does not come in contact with the pads. There are several YouTube videos describing the bleeding process.

    3. A buddy or a son that help you. This is certainly a 2 person job.

    Tools required:

    1. A low profile jack

    2. Jack stands and wheel chocks

    3. DOT 3 brake fluid (one quart is sufficient)

    4. Turkey baster and gallon Ziploc bag

    5. An empty bottle and a funnel

    6. 5/16 inch ratchet

    7. A small pry bar

    8. Brake bleeder kit with magnetic bottle holder (the cheapest one will work fine)

    9. Nitrile gloves (5 mil)

    10. A flash light

    11. A piece of wire (or optionally a 1K ohm resistor)

    12. Old newspapers and paper towels

    Steps for replacing brake fluid and bleeding brakes

    Step 1: Remove the filter from the brake fluid reservoir

    Always use nitrile gloves for this project. Surround the reservoir with old news papers and paper towels. As the filter can be slippery, I used a small pry bar around the edge to get it out. Once it was out, I used the gallon Ziploc back to store it.
    Step 2: Empty the brake fluid in the brake fluid reservoir

    Use the turkey baster to empty the contents of the reservoir into a bottle. Preferably use the funnel to prevent any spillage.

    Step 3: Fill the brake fluid reservoir to the max line

    Fill it with the DOT 3 brake fluid and use a clean funnel. Clean the filter with a paper towel and put it back on.

    Step 4: Put the Prius in diagnostic mode

    To put the Prius in diagnostic mode, find the OBD2 port under the dash below your right knee. When looking up at it, you will find a connector with 2 rows of 8 pins each. Connect a jumper between pin 4 (CG pin) and pin 13 (TC pin) on the OBD2 connector. Starting at the top row reading from left to right, pin 4 would be the pin 4 pins away from the left on top row. On bottom row pin 13 would be 4 pins from the right on bottom row. I used a 1K ohm resistor as insurance in case I accidentally shorted the wrong pins.
    Prius-OBD-II-Port.jpg
    Next press the power button twice without pressing the brakes. The car will take a few seconds to boot up and you shell see a diagnostic menu on the display.

    Step 5: Jack up the back of the car

    It is best to bleed the RR (rear right) and RL (rear left) brakes before working on the front brakes.

    Step 6: Get ready for bleeding the brakes

    Remove the rubber cap on the RR bleed valve. Put a 5/16 inch ratchet on the valve followed by the brake bleed bottle. If you are using the bleed bottle for the first time, it might require some effort to get the tube on to the bleed valve. The remaining three wheels will be a lot easier. Using a flash light helps.

    Once the bleed bottle is in place, loosen the bleed valve. As the rear brakes are controlled by an actuator, you don’t have to open and close the bleed valve, the way you would do for a gravity bleed.

    Step 7: Have your buddy press the brake twice

    Every second time the break actuator will come up for 5 seconds and you should see some brake fluid come out of the valve. I saw some small bubbles in the brake fluid that initially came out.

    Step 8: Close the bleed valve

    Once the bleed bottle is more than half full, close the bleed valve and replace the rubber cap. Add more brake fluid to the reservoir if the level goes significantly below the maximum.

    Step 9: Repeat steps 6, 7 and 8 for RL brakes

    After the RR and RL brakes are done, take the car off the jack stands.

    Step 10: Switch off the car

    Press the power button to turn of the car completely. This is required before the next step. Removing the relays while the car is turned on can damage the electronics.

    Step 11: Remove relays 1 and 2

    These relays are shown in the attached picture. They will disable the actuator during the front bleed.
    Relays_1_and_2.JPG

    Step 12: Put the Prius in diagnostic mode

    Same as step 4

    Step 13: Jack up the back of the car

    It is best to bleed the FR (front right) and FL (front left) brakes in that order.

    Step 14: Get ready for bleeding the brakes

    Remove the rubber cap on the FR bleed valve. Put a 5/16 inch ratchet on the valve followed by the brake bleed bottle. In this case the ratchet can possibly go too far towards the wheel and start slipping. Try to keep it in the middle.

    Do not loosen the bleed valve. For the front wheel we are using the gravity bleed method. It is normal to hear a high pitched noise.

    Step 15: Have your buddy press the brake four times and hold

    Pressing the brake four times build up pressure. On the fourth time you need to keep the brake pressed to prevent air from getting back in to the brakes.

    Step 16: Open and close the bleed valve

    Opening and closing the bleed valve will result in brake fluid flowing into the bleed bottle. Steps 15 and 16 may need to be repeated.

    Once the bleed bottle is more than half full, replace the rubber cap. Add more brake fluid to the reservoir if the level goes significantly below the maximum.

    Step 17: Repeat steps 14, 15 and 16 for the FL brakes

    Remove the jack stands once FR and FL brakes are done.

    Step 18: Reset warning lights

    Removing the relays 1 and 2 will result in several warning lights. To remove this run the following reset procedure.

    Turn off the car. Replace the relays. Put the car in diagnostic mode as in step 4. Press the brake pedal 8 or more times in 5 seconds. This will reset all warnings.

    Step 19: Get out of diagnostic mode

    Turn off the car. Remove the jumper and restart the car. It should be back to normal.

    WARNING: Right after the brakes have been serviced they will feel a little weak. Make sure you have enough room around the car when driving. After a few uses they should return back to normal. Within 30 minutes of use they were much sharper for me than before the service.
     
  2. hchu1

    hchu1 Active Member

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    Excellent write up. (y)
     
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  3. exstudent

    exstudent Senior Member

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    Good job, buy why make life so hard?

    Seriously, if you are going to DIY, just get mini VCI w/ a hacked copy of Techstream from Amazon or ebay. Obviously you'll need a laptop as well.

    Hate to rain on your parade, but you will have to redo your brake flush as it's incomplete. According to Galaxee (a very helpful Toyota Service Tech here on PC), the Prius brake system contains just under One Gallon of DOT3. See post #1: What services you need and what you don't | PriusChat. You have 3 quarts of old fluid still in the system.

    You could have done all 4 wheels in under 40minutes by yourself. Helps if you have a vaccum bleed tool for use on the front brakes.

    I have read on here, that dealers charge $100 for this.
     
    #3 exstudent, May 4, 2015
    Last edited: May 4, 2015
  4. mark5211

    mark5211 Junior Member

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    Great write up and follow up comments. I have a mini VCI w/ techstream and I'm going to replace the brake fluid in my 2008 gen II. Obviously, I don't need to jumper the port. Are there any other differences using a mini VCI vs this write up? How do you get the full gallon out of the system? Bleed more out of each wheel cylinder? Thanks in advance.
     
  5. Billy Hansen

    Billy Hansen New Member

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    I have to do some brake bleeding because my front calipers need replacing due to uneven wear on the brake pads. Anyone know if there are any extra steps involved? Or is it just as simple as swapping the brake lines from the old caliper to the new ones during step 14?
     
  6. LEVE

    LEVE Member

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    Before you start replacing calipers, do you know they're bad? If one caliper is not releasing it could be due to the slide mechanics being gummed up and not letting the caliper release. I'm assuming you're thinking the caliper piston is sticking due to bad fluid and debris building up in the lines. That may not be the case.

    Replacing front calipers on a Prius is not a simple job unless you can exercise the brakes to fill those calipers with fluid. You'll need a way to do that. A mini-VCI should do that, it's about the least expensive way I know of to do it.

    I hope someone else may chime in if I'm wrong.
     
  7. Billy Hansen

    Billy Hansen New Member

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    Well, I just had winter tires put on at a place called Tire World and they said that since the calipers were causing uneven wear the needed to be replaced with the brake pads.

    I've thought about a mini-VCI, but since the original poster of this thread said it was possible to bleed the brakes without one, I was going to go ahead and try the jumper wire he suggested. Sounds like it's a pain to get Techstream installed on a modern computer. Though if someone knowledgeable can explain to me the benefit of using one, I may be willing to go through the trouble.
     
  8. edthefox5

    edthefox5 Senior Member

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    if you just swap the brakes line to a new caliper the abs will detect a fluid leak and the relays slam shut and you will have no brakes.
    And alot of dash lights lit. Prius brakes are very tricky. You have to at the least remove relays as stated in the OP's post.
    Most use mini vci techstream to manipulate the relays like the dealer does.

    If you don't know what your doing it usually results in a flat bed ride to the dealer. Hilarity quickly ensues upon your wallet.
     
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  9. Billy Hansen

    Billy Hansen New Member

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    Alright, after looking into Techstream a bit more I learned that it also allows me to change settings in the car, like unlocking all of the locks with one button push instead of two. So I revived an old laptop and installed a 32bit version of Windows 7 on. I bought a $25 Mini VCI cable, installed Techstream, and happily changed the settings.

    One question I still have is I heard that you need to keep the keys away from the Prius while working on the brakes. Is that case with brake bleeding as well? Because in step 4 he says to press the power button twice, but I can't do that without my car alarm going off.
     
  10. SFO

    SFO Senior Member

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    PLEASE : Reread all of the above instructions (and any warnings) just to be safe.

    If you are only on step #4, you should be ok with hitting the power button twice (foot off brake) while the fob is near.

    After you make it past step #11 (removal of two relays) you should also be safe with still having the fob near the vehicle.

    Though I've yet to do it myself, you should be able to bleed the brakes from within techstream using onscreen step by step instructions.
     
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  11. Billy Hansen

    Billy Hansen New Member

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    SUCCESS! Just got the new calipers and pads installed and the brake bleeding went smoothly!

    I went ahead and put my keys inside the house while I replaced the calipers. (I still had the old calipers connected to the brake line, though) As per your suggestion SFO, I removed the relays right before grabbing my keys. I heard a click when I opened the doors, but no brake actuator noise. I turned on the car by pressing the power button twice without pressing the brake, connected Techstream, and started up the Air Bleeding utility. I choose Usual brake bleeding, and I was happily surprised that it let me choose which line to start bleeding first. It then walked us through steps, 14-15 zak.kapoor listed above. Once it said to start bleeding, I disconnect the brake line and connected it to the new caliper. Techstream added one more step saying to stay in the car for 2 minutes before opening the door. We then heard a click and proceeded to the next caliper

    One slight mistake I made was not transferring the other brake line to the other new caliper at the same time as the first one. So when my friend started pumping the brakes it caused the other old caliper's piston to fully come out. But since I was replacing the caliper anyway it didn't matter. It just caused some extra brake fluid to spill out when I set down the old caliper. I repeated the processes for the other brake line and there were no warning lights that came on in the dash!

    So if you have access to a 32bit version of Windows, then I would highly recommend getting a cheap version of Techstream with a Mini VCI cable. It's way cheaper than a $200-$300 laptop with it already installed on Windows XP. Plus you get to read error codes and configure car settings!
     
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  12. N88GUM

    N88GUM New Member

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    Great write up and worked a treat when I replaced a rear caliper on my wife's Gen2.
    No software required and no error codes. Thanks, really appreciated
     
  13. blaisep

    blaisep Junior Member

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    This is an excellent write up, thank you. re: @Billy Hansen caliper episode, I encourage everyone to read Hobbit's exemplary description of the care of sliding pins: Brake service
    I have found that the sliding pins often stick and the inner pad wears down much faster.
     
  14. Matthew Leeser

    Matthew Leeser New Member

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    Would anyone verify the hex bolt size on a 2005 Prius for the brake bleeder?
     
  15. Lovemymia

    Lovemymia Junior Member

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    How do I save these posts and comments so I can retrieve it w(en log back in? May be stupid question but I spend allot of time searching for threads I’ve read and need to refer to.
    Thanks
     
  16. exstudent

    exstudent Senior Member

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    Its called a BOOKMARK.
    Your web browser (Internet Explorer, Safari, Firefox, Chrome, etc) has the ability to save the web pages that you like/visit often, for easy/fast retrieval.

    As you find PriusChat threads that you like or find useful, BOOKMARK them. Now you will be able to instantly pull-up the thread w/o having to do a search.
     
  17. SFO

    SFO Senior Member

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    Great question actually, and I wish there was a better answer.

    Whenever you post to a thread there should be a record of it here : https://priuschat.com/search/member?user_id=142229

    You can change your alert settings here : https://priuschat.com/account/alert-preferences

    It is possible to follow threads that you haven't posted on, by clicking the 'Follow Thread' link in the upper right corner of the first posting where the thread was initially started (page 1). Depending on your alert settings, you should be alerted when there is activity on a 'followed thread'.

    Though I could be mistaken, there is no way to separate 'watched threads' from contributed threads, its all one big mess of history.
     
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  18. Mendel Leisk

    Mendel Leisk Lapsed Cargo Cultist

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    Some assumptions regarding what you have, but you could print what you need, or print to pdf, or highlight the text, copy, and paste into a text document.

    Lots of ways to skin a cat.

    Bookmark is my first option too, but when I really want to squirrel things away, I use the more permanent methods. Videos for example: there are ways to download them to your hard drive.
     
  19. Lovemymia

    Lovemymia Junior Member

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    Thank you Prius pals for your reply’s.....Bookmarks it’s is!!!!! Have a great day
     
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  20. Mendel Leisk

    Mendel Leisk Lapsed Cargo Cultist

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    There is a procedure for brake bleed without Techstream in the third gen Repair Manual, sadly haven't found similar in the second gen Manual.
     
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