Brake Accumulator Pump vs ABS Accumulator Pump

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by outahere, Oct 2, 2021.

  1. outahere

    outahere New Member

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    Is there both a Brake Accumulator Pump and an ABS Accumulator pump? I have always thought there was one assembly with a master cylinder, accumulator, booster & pump. And, that it is just that some people say ABS accumulator when they are troubleshooting the ABS systems and Brake accumulator when troubleshooting the breaking system. But they were the same thing. Before I go to battle with an extended warranty company I wanted to check if I am incorrect.

    My wife has a 2013 Prius. I have worked on a lot of cars but not a Prius. When she bought the car used in 2018 she also purchase an extended warranty. She starting hearing a "chirping" noise when applying the breaks. The car was due for an oil change so she took it to the Toyota dealer she purchased it from. She told the service advisor about the noise.

    In his report, he stated, "Needs brake booster with master cylinder & accumulator pumps". So she contacted the warranty company. Their agent said none of the items are covered." Here is what is in the contract:

    BRAKES Brake master cylinder; brake power assist boosters; brake power assist valves; disc brake calipers; bleeders; brake adjusters; backing plates; brake
    pedal apply pin; wheel cylinders; combination valve; proportioning valve; metering valve; brake hydraulic lines and fittings; vacuum and fluid reservoirs;
    hydro boost unit; parking brake cable; pressure differential switch; brake fluid level sensor; residual pressure check valve; return spring; self adjuster mechanism;
    springs clips and retainers; parking brake lever; parking brake ratchet assembly.
    ABS SYSTEM – ABS booster; ABS pump/motor; ABS control processor; ABS dump valve; ABS sensors; ABS solenoids; ABS electronic control compressor; ABS
    hydraulic control unit; ABS modulator valve; ABS compensating valve; ABS accumulator

    The master cylinder and the brake booster are very obviously listed as covered. Would I be correct in stating the "Accumulator Pumps", yes pumps and not pump in the report, is covered by the items under ABS SYSTEM that I have in bold and underlined?
     
  2. rjparker

    rjparker Senior Member

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    First, chirping may mean worn out pads.

    There are two separate units in a gen3 Prius. One pump/accumulator and one master cylinder/abs/stroke simulator/brake ecu. They are expensive, usually around $2500 installed at a dealer. They are covered by Toyota if they throw codes and the car is under 150,000 miles. In general they have all the functions you list but also have integral brake by wire control functions in a regen car that normal systems don't have. They don't hydraulically brake at all when the regen function can do the necessary deceleration, especially at speed. Unfortunately third party extended warranties are usually scams to sell cars.

    Part numbers vary by year and wheel size.

    Prius master cylinder assy.jpg Prius pump assy.jpg
     
    #2 rjparker, Oct 3, 2021
    Last edited: Oct 3, 2021
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  3. ChapmanF

    ChapmanF Senior Member

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    Based on what I'm reading there, I think they should cover it. Now, whether it costs you more to get a judgment out of them than what the judgment is worth, I can't predict ....
     
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  4. Kate M

    Kate M Junior Member

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    Just bought a 2013 used with 72K miles and within one day of driving knew there was a brake issue.
    Took it to dealer and so far I've been told it needs both Accumulator and Master Cylinder.
    It's so hard to find a good used car right now (my beloved 2005 was totaled 3 weeks ago when I was rear-ended and pushed down a ditch) but here I am with a sweet car that has issues from the get-go.
    Is it worth repairing and keeping it, or will this issue come up again and again?
    I need to decide today, or return the car tomorrow and pay $300 and be done (but car-less again).
    Help :-(

    ChapmanF has been following my issue...somehow I'd like to tag him in this reply.
     
  5. ChapmanF

    ChapmanF Senior Member

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    72k is early for those brake components to go. Mine are (looks for wood to knock) beyond twice that so far. If you have yours replaced with new, it should be a good long while before they'd be an issue again.
     
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  6. outahere

    outahere New Member

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    She is a retired attorney and knows how to work the system. For her, it will be like a hobby or sport. She needed to verify the mechanical jargon. I have worked on a bunch of cars but not a hybrid so I wanted to make sure she was properly informed. Thank you.
     
  7. outahere

    outahere New Member

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    Thank you for the details and the pictures. She has had the car for just under three years. The brake pads were replaced in the first year and have less than 25k miles on them. I read about Toyota's voluntary replacement program if there are warning lights on. It is hard to understand the logic. She has been told, in writing, by a Toyota dealership the parts need to be replaced. Toyota must not trust its own service manager's opinion and would rather wait for the system to fail. We are not talking about an AC system but one of the most critical systems in a car, the braking system. The codes are not always thrown letting you know it is about time to get the breaks fixed. They are not like the "low fuel" or "TPS" lights or else they would all be yellow. Now here is some irony. Just now, my ex-wife just called and said the brake lights turned and immediately she barely had enough brakes to stop the car. Luckily, she was only a couple of blocks away from her home. I'll have the car towed to the Toyata dealer tomorrow morning.

    I'll update everyone on the outcome.

    Thanks again for all the help
     
  8. rjparker

    rjparker Senior Member

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    Age can be a factor. The dealer will want ~$2,500. Verify that Toyota won't cover it under the Secondary Coverage "10 year under 150,000" program for this fault. See pic for my v wagon which has a different Primary expiration.

    Concerning returning it tomorrow for a refund, a lot depends on how much you paid. There are other potentially expensive problems with a 2013.

    5E872624-C7F4-4D2F-A9F8-BC854FBFF4EA.jpeg
     
    #8 rjparker, Oct 18, 2021
    Last edited: Oct 18, 2021
  9. Kate M

    Kate M Junior Member

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    Dealer estimate is $1,700 and said no warranty for this.
    Also, we’re clear this is not a “Brake Booster”, correct? That’s a different repair?
    What are some potentially expensive problems with 2013?
     
  10. rjparker

    rjparker Senior Member

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    The brake booster is the accumulator and master cylinder. I would ask them to check for the customer support program. Some don't routinely check. For $1,700 they are giving it to you close to cost.

    Other problems with higher mileage: Excessive oil consumption defined as a quart every 1200 miles. Failed inverter may strand you but it should be covered by a customer support program. Poor egr design that requires an $800 maintenance periodically unless you are advanced diy'er. The intake manifold fills with oil. Head gasket failures that sometimes take out the engine. Of course eventually the hv battery replacement.

    Again I would not pay a premium price for this car.
     
    #10 rjparker, Oct 18, 2021
    Last edited: Oct 18, 2021
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  11. Kate M

    Kate M Junior Member

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    Omg. That’s a long list.
    Thanks for chiming in here.
    What do you consider higher mileage?
    I drove my 2005 for 16 years, replaced hybrid battery at 120k miles, and would still be driving it had I not been rear ended.
     
  12. rjparker

    rjparker Senior Member

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    Most gen3 problems in the past have started around 150k miles. Now we see a lot of them at 125k. Your car had a brake booster at 72k so miles may not be the only metric. Most of these problems have been acknowledged by Toyota and were fixed for free initially but most don't qualify for free repairs anymore. The egr and oil in the intake have never been officially declared an issue by Toyota but egr clogging of gen3s Prii is the poster child problem on Priuschat.

    A lot of the regulars here are diy'ers who have Techstream scanners, will tear their engines down to fix their own head gaskets and egrs, have good knowledge and tools, think nothing of changing components inside their failing high voltage batteries, you name it.

    In the end its a risk reward decision. You can change oil every 5k and do major maintenance on the egr every 75k. You would have a new brake booster and the inverter stranding is a once in ten year experience. Maybe you do have a head gasket failure in your ownership - maybe not with accelerated maintenance. Personally I would find a 2016 or newer gen4 Prius where a major system redesign fixed these problems.
     
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  13. ChapmanF

    ChapmanF Senior Member

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    Those are both of the animals shown in rjparker's picture in post #2.

    If the dealer will change both of those for $1700, that's a great deal (if not as great as covering them under ZJB).

    Both animals go by multiple names. Here's another picture of the same two things, showing more of their names:

    [​IMG]

    Whatever you call them, if you're getting both things, that's pretty much all the things, as far as the underhood brake hardware goes.

    My Gen 1 intake manifold had a pool of oil. You probably drove your Gen 2 for 16 years with a pool of oil in the manifold. Prius intake manifolds get pools of oil.
     
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  14. Kate M

    Kate M Junior Member

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    My 2005 was the best financial decision I ever made. Not a single repair until hybrid battery replacement. It’s devastating to lose that in a no-fault accident (with injuries too) and no insurance payout can reimburse the value of a truly dependable car.
     
  15. Kate M

    Kate M Junior Member

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    Thank you for sharing this valuable info. Helps to hear it from an objective person with no monetary interest in the decision.
     
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  16. Kate M

    Kate M Junior Member

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    Response from Toyota Dealer on repair and warranty coverage:

    I completely understand your point of view. The CSP will cover the brake booster when there is a concern with the brake booster itself which is like the brains of the brake and traction system. As per the CSP, when that happens, you get the failure codes associated with the concern. The concern that you are having is that the nitrogen tank attached to the brake booster is leaking. My shop foreman and the parts department are working together on the estimate. It does appear that the estimate I sent is incorrect so as soon as they get that info back to me, I will get it to you
     
  17. rjparker

    rjparker Senior Member

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    Your service advisor does not know what he is talking about. Pretty common. The "nitrogen tank" is part of the accumulator and is the heart of the csp covered problem. In fact, Toyota initially repaired only the accumulator (also known as the pump/accumulator) because the nitrogen being compressed by the pump was leaking through a metal diaphragm into the brake fluid. The pressurized brake fluid is stored in the accumulator until the master cylinder needs it to apply the brakes. More than you need to know and certainly more than your service advisor knows.

    Maybe the system is not generating the proper trouble codes yet. This does happen. The csp lists several that will trigger the free replacement. One has to do with how long the pump/accumulator has to run to build pressure. Your pump "may" not run long enough yet.

    The fact they are revising the quote makes me wonder if they are up to something. Are they getting paid from Toyota and maybe from you as well? Probably not but makes for a good conspiracy theory.

    One thing to remember is dealers are not making money on new cars due to a lack of supply. So they jack up used car prices (as has everyone) and they make money on parts and service.

    Don't fall in love with this car on the first date even if it is the only one calling.
     
    #17 rjparker, Oct 19, 2021
    Last edited: Oct 19, 2021
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  18. Kate M

    Kate M Junior Member

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    They just quoted me $2,980 for repair. I hear you on all the points...and I did my best to justify...no coverage.
    I'm taking the car back to the dealer who sold it to me and will pay $500 fee (crazy, but that's the cost) of getting my money back. They did agree to reimburse me the $190 diagnostic fee I paid to Toyota.
    Someone must have known something was up with the braking system before I got this car, but it was handed among so many people so quickly, and none were Prius pros.
     
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  19. vvillovv

    vvillovv Senior Member

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    I've only read 5 or so posts above since I missed a few yesterday / today. After reading @rjparker s post above your 2 last posts, I got thinking about the $500 restocking fee, call it hindsight because that's what it is, but that just sounds phishy like from a dealer selling a car needing a
    repair within hours of taking ownership.
     
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  20. Kate M

    Kate M Junior Member

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    Yes, when I called the general manager last night I told him I was an unhappy customer and he basically said too bad, then return the car. This morning he called and said he's having his service manager call Toyota's service department. If they strike a deal to pay for the repair and let me keep the car, then great. Either way, they will have to deal with this repair.
     
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