Throttle Body and Mass Flow Service

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cubbyg, Dec 25, 2012.

  1. cubbyg

    cubbyg Junior Member

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    My 2006 with only 42K just returned from the dealer after performing a recall inspection. Their complimentary inspection recommended cleaning the throttle body and mass flow. My engine exhibits no performance issues and mileage averages 48-50 mpg. :) Visual inspection of throttle body opening reveals slight black deposits on the edges of the butterfly and a little pool of fluid/oil at base of opening. Recommendation appears very premature and unnecessary. In addition they recommended a brake fluid and A/C flush. I might splurge and dump a can of Techron in the tank as recommended in other threads. Not interested in buying stock in my local Toyota Dealership and found this great link for help, Cleaning Prius Throttle . Any thoughts on their recommendations? Thanks
     
  2. edthefox5

    edthefox5 Senior Member

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    No the tb cleaning is due. Most modern cars get pretty sooty. The issue being that black soot on edge of the brass butterfly turns into rust after a while and that's not good. That tb retails for $1500. I did mine at 15K.

    Brake fluid flush is not a really bad idea as the car is now 7 years old. Not sure where you live as you did not post it
    but up north may be harder on brake fluid. Plus the rear drums could probably need a cleaning too. In the meantime I just suck out all the fluid in the reservoir on mine with a turkey baster and refill it. It helps. Problem is the dealer wants an arm and a leg for the flush.

    Try my method of tb cleaning. Buy 2 cans of spray carb cleaner. Get an old t shirt or towel and rip it in 3 in strips.
    With the butterfly open shove a strip down the tb throat and then soak the strip with carb cleaner. Using the soaked strip scrub the throat and butterfly as best and as deep as you can. Pull the strip out and throw away. Repeat. This prevents a big pool of cleaner and grime from entering the intake. When done spray lube the throttle linkage spring. And don't forget to tighten the clamp under the air cleaner housing that goes around the lip of the tb.
     
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  3. SageBrush

    SageBrush Senior Member

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    I take it this means the fluid in the reservoir circulates and admixes ?

    If so, I like the idea and am going to adopt the practice as an annual maintenance. I was thinking of doing something similar for the ICE coolant to avoid the hassle of burping the system.

    OP: Ed's advice is going to cost you about $5/year + an old t-shirt
     
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  4. cubbyg

    cubbyg Junior Member

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    Ed. Great ideas for cleaning up the T-body! I got old tee shirts. What about the mass flow cleaning with isopropl alcohol or MF cleaner? Too soon or go for it?
     
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  5. edthefox5

    edthefox5 Senior Member

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    Mass flow cleaning is a little tricky as its easily damaged. They sell a spray can specifically for MAF cleaning at auto store. Just spray it out. T Shirt idea cannot go wrong. Instead of flushing all that gunk down into the intake your actually cleaning it out. Works very good. I have cleaned so many tb's in my life.
    The sad truth is you really need to take the tb off to do it right but my method will get you real close.
    Good Luck!
     
  6. jayman

    jayman Senior Member

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    How do you flush an air conditioner?
     
  7. edthefox5

    edthefox5 Senior Member

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    Hi yes its cheesy I know and for the brakes may not accomplish much but at least its new fresh fluid in there. And it would work pretty good for the Inverter coolant. SLLC is pretty cheap.

    But I gotta tell you though I got a very good bump in mileage by changing the Invert fluid and adding Redline Water wetter. The cooler the Inverter the more efficient it is. And poor efficiency= gasoline. New coolant and it ran 5 degree's cooler in the summer. I tracked it with my IR thermometer.

    Best medicine you can do for this car is new Inverter coolant.
     
  8. edthefox5

    edthefox5 Senior Member

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    Hey Jayman where you been? How are you doing?
     
  9. PriusGuy32

    PriusGuy32 Prius Driver Extraordinaire

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    Very little. The idea is to get the brake fluid out of the lines/calibers/rear cylinders because over time water will get absorbed into the brake fluid (its hygroscopic) and heat will degrade it. Turkey basting the fluid out of the reservoir does nothing at all unless you are opening the bleed screw at each wheel and flushing the old stuff out, letting the new stuff in the reservoir take the old fluids place.

    For comparison, here is new brake fluid (left) and the old brake fluid with about 65000 miles and 5 years of use on it when I flushed my old 2002 GMC Envoy's at each bleeder on the right:

    [​IMG]

    Brake fluid definitely degrades over time and at some point a brake fluid flush is a good idea.

    Ive NEVER heard of an A/C flush unless the compressor grenades and they flush the lines to get all of the debris out, thats gotta be just a money maker for the dealership. I bet they clean out the drain tube to the evaporator core and call it an "A/C flush". LOL
     
  10. jayman

    jayman Senior Member

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    Working my butt off with a "promotion" that requires far more hours, almost zero free time

    But I am not complaining. Jobs are scarce now
     
  11. jayman

    jayman Senior Member

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    Agreed on both points
     
  12. SageBrush

    SageBrush Senior Member

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    Luckily, inverter coolant is a lot easier to exchange and purge air from than the ICE circuit.
     
  13. cubbyg

    cubbyg Junior Member

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  14. edthefox5

    edthefox5 Senior Member

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    Glad you liked it. Thats the way to do it take the air box off. You just extended the life of the TB years. That TB is very expensive. Cause if an owner rolls into the dealer with a poor running car and the butterfly is all rusted around the lip they will put a new tb on the car. Thats a $2000 day.
     
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