the gas bladder: exposed!

galaxee · Apr 6, 2007

quick introduction: this was the second bladder that DH has replaced for overfill damage. he decided to take it apart after work because his wife is extremely cranky right now writing her NRSA grant :lol:

here are the pictures. it was a hell of a lot of work, and the poor guy now is sitting next to me with an ice pack on his shoulder! enjoy!

oh, and if you wanna know more about overfill damage/why the tank was replaced in the first place, look here.

1. the whole assembly out of the car.

2. circular thing: electrical main. powers fuel pump, sending unit, temp sensor. small tube sends fuel to the engine. big tube, probably evap.

3. filler pipe with retaining nut. red thing... something to do with the evap system. have to dig more into that.

4. nut taken off filler neck, neck shoved all the way into tank. you can see the first cuts to the metal housing.

5. cutting...

6. cutting...

7. cutting... ooh!

8. quick close-up during cutting...

9. "cutaway" (huh huh) view of filler neck and "everything box" (aka fuel pump, fuel filter, sending unit, all that in the box there)

10. one of 4 corner nuts holding bladder down

11. a-ha!!!

12. finally... time to use the air tools, beeotch!

13 & 14. and air tools take a severe beating...

15. but prevail in the end!

16. it's like a tin can! and yes, there was a half cup or so of gas in there from the overfill.

17 & 18. rubber corner mount for the bladder.

19. bladder and all other stuff, removed from tank housing

20. a better shot, maybe.

21. bottom of the bladder, where the fuel line comes out and goes to the sending unit/"everything box"

22. bottom of the bladder again, now looking at where the fuel line goes to the box. he is holding on to the filler neck.

23. the everything box: with temperature sensor, fuel pump and sending unit wiring, and fuel pump outlet.

24. the bladder and associated stuff sitting on a bucket in a drain pan.

25. for size reference. DH has about average to small sized hands. dear, where's that wedding ring?! :lol:
he doesn't wear it at work, actually. but i assure you the man is taken!

epilogue: the "everything box" is up on the chopping block tomorrow. just cutting away the metal housing took about 90 minutes tonight!

the fuel sending unit was of particular interest given the "guess gauge" thing... so there are lots of pics of that.

1. just the "everything box"

2. different angle, minus hoses and such

3. minus top of case. here you see where the fuel goes in and pools, and levels out for the sending unit (the thing that tells the gauge what to read) to measure.

4. top of the case, with fuel pump (with screen), fuel filter, and sending unit with float. here all this time we had been thinking it was a magnet in a tube...

5. flipped over for a better view of the sending unit.

6. better angle of the fuel pump and etc. the cap is removed from the end of the fuel pump housing. on the top right is a no-fluid valve that leads to the vapor side of the charcoal canister.

7. fuel pump

8. housing without pump. the port up in there is where the fuel goes from the pump, into the filter.

9. pump/filter housing removed from top of case. there is no getting that filter out without some serious tools that we don't have handy at the moment. the metal deal on the top is the fuel pressure regulator.

10. ahh, the sending unit. the heart of the guess gauge.

11. one where the gauge would be displaying full

12. the moving contacts from the arm

13. minus the arm

14. close up of the number of different contacts. anyone care to count them?

15. size reference...

... and there it is. the whole gas tank pulled apart for your viewing pleasure.

ghastly thing... :lol:

Beryl Octet · Apr 6, 2007

Cool set of pics, thanks for sharing them with us!

TonyPSchaefer · Apr 6, 2007

Holy cow!! That's one complicated fuel tank!

Thanks for the pictures.
You know, ice helps curb pain a lot faster if it's in a mixed drink.

galaxee · Apr 7, 2007

wait a sec... this one shows no pics... there is a duplicate thread that shows them all... did i screw something up? :blink:

edit: nevermind. now they show up... gah!

Tideland Prius · Apr 7, 2007

lol

wow.. so the bladder is just a black rubber... bladder haha.

interesting. Didn't know the fuel tank was like a big waffle.

Bill Merchant · Apr 7, 2007

Thanks for all the pics, Galaxee, and thank your hubby for his interest and spending a couple of hours on this project. I hope everyone who tries to force a few more squirts into the tank can now understand why they shouldn't. How much does an R&R of the gas tank cost?

Tony, can you fix these two posts? The one with the paperclip icon has no pics, and this one does, but no icon. Is the database getting screwy?

galaxee · Apr 7, 2007

cost runs total between 4 and 5 hours labor (more or less $80/hour) depending on how FUBAR'd things are. and the tank cost like $380 which isn't bad considering when we put a fuel pump in his old camry they wanted like $200 for the pump alone!

Godiva · Apr 7, 2007

Well, now the pics show up on this thread and not the other.

Whatever.

That is really cool.

Did he take it apart just to see inside or is there some sort of repair that involves having to take it apart. Is it recyclable and being sent back? (What's the deposit on that thing, LOL)

What did the repeated overfilling do to warrant having to remove the tank/bladder? How do we know if we're doing that? I've never had gas spurt back out at me. But I also fill past the first shut off too, because of the bladder.

HTMLSpinnr · Apr 7, 2007

Define overfill... I've nursed mine many times to the neck w/o apparent consequence. Was this a violent overfill which ruptured the bladder?

galaxee · Apr 7, 2007

this is from the car i talk about in this thread

godiva: this was just for the sake of taking the thing apart. there's really nothing that can be repaired in there, just replaced.

he's kinda recycling it... the metal part is galvanized steel that goes in scrap metal for recycling. he's eventually using the resin part of the bladder for a fluid catch pan. the "everything box" is probably not recyclable.

galaxee · Apr 7, 2007

okay now bear with me folks, i just tried to remove that duplicate post and as expected, and following in the trend that has been my hellish experience with trying to do ANYTHING right in the past week... i just dumped all the pics in this thread by deleting that other thread... i don't get it... #$(*%$()&*(*&()$%^*

sigh...

edit: okay, this should fix the issue once and for all. man i really did not want to have to go and re-upload all that crap but here it is. and a good night to all!!!

tripp · Apr 7, 2007

Galaxee, thanks for taking the time (yer DH too, of course) to show us this. On the one hand, it's really cool. On the other hand, it seems ridiculously complex for a bloody fuel tank.

aaf709 · Apr 7, 2007

I agree with tripp that's pretty complex.

Thanks for the pictures!

bwilson4web · Apr 7, 2007

I have an NHW11 and the filler is on the passenger side. I'm trying to figure out how the filler tube routes from the photos. Also, I'm trying to understand what it takes to replace the tank since the Toyota 2003 maintenance manual just shows the tank, not how to replace it.

Is this tank from an NHW20 or NHW11?
Does the NHW20 have the filler on the driver side?
In figure 1, are we seeing the tank top or bottom?
I noticed two holes on the opposite side of the tank in figure 1, what do they connect to?
Does tank removal require taking out the rear axle?

These are great photos and I'll add a note to the GH Prius FAQ about the overfill risk.

Thanks,
Bob Wilson

hobbit · Apr 7, 2007

How absolutely excellent. Thanks to you both, you totally rock!
.
So the box of "Toyota seal packaging" wasn't so that DH could put the
thing back together, huh?
.
I've gazed long and hard at the pics of the tank in the NCF and some
other places, wondering more about what's in there and the bladder
characteristics... and the fact that the EVAP system actually pulls
air through the surrounding steel tank and *checks* it, using the A/F
sensor while the engine's running, for any fumes! They really don't
want any gas outside the bladder, even though the rest of the tank is
pretty much sealed up. Here's a cleaned-up rework of one of the
pix from the "university of Toyota" stuff, which I think is now also
available at autoshop101.com:
__ http://techno-fandom.org/~hobbit/pix/udh2/800/bladder.jpg
which must be from a NHW11 because it looks a bit different.
.
The bladder seems to have much more shape and rigidity than just a
rubber bag, so there must be times when it has *some* vapor above the
fuel inside it... now, the big question is this: where does the
overfill fuel go, i.e. what path does it take to actually get into
the outer tank? Since the bottom of the bladder and everything-box
are sealed with respect to each other, it's got to be out through
the fresh-air inlet or purge system and back in somehow.
.
By contrast with the fact that this one is sealed up and one must
replace the whole wazoo to repair any of that stuff in the everything-
box, take a look at the "fuel tank R2D2" in
__ http://www.99mpg.com/Workshops/understandingdiagn/
a larger version of which is at
__ http://techno-fandom.org/~hobbit/pix/udh2/ios/iostank.jpg
and note that the black "jar lid" screw ring around the white piece
is how you get the fuel pump out of an Insight tank [non-bladder,
of course]. Something like this seems to be a much better design
for serviceability, rather than having to replace the entire tank!
There are some places where I look at Honda and Toyota and go "okay,
what the heck was [one of them] thinking?!"
.
Sorry about the somewhat "advertisey" link, but we really are trying
to get independents into these seminars. Mike is a total *monster*
with a welder as you can see, and has done the vast bulk of the work
on these projects.
.
I hope to have a similarly detailed expose' of the inverter up at
some point ...
.
_H*

Beryl Octet · Apr 7, 2007

<div class='quotetop'>QUOTE(galaxee @ Apr 6 2007, 11:41 PM) [snapback]419197[/snapback]</div>

quick introduction: this was the second bladder that DH has replaced for overfill damage.
[/b]
Click to expand...

So, putting too much fuel in causes damage to these? I assume by damage, you mean they start leaking?

galaxee · Apr 7, 2007

bwilson- this is from a NHW20. the filler is on the driver's side. i'll ask DH tonight if he's pulled a tank from a classic prius. the first pic is the top of the tank, and the two holes you ask about are for a couple of sensors, i forget which ones he said they were. one is the sensor that detects fuel in the space between the bladder and the metal tank.

hobbit- i knew you'd be all about this :lol: i'll have to wait for DH to answer all your questions, i'm sure he was expecting a few discussion points from this thread!

beryl- fuel in space between tank and bladder. very, very bad. check out the thread discussing what happened to this car here: http://priuschat.com/index.php?showtopic=30786

bwilson4web · Apr 7, 2007

<div class='quotetop'>QUOTE(galaxee @ Apr 7 2007, 10:53 AM) [snapback]419365[/snapback]</div>

bwilson- this is from a NHW20. the filler is on the driver's side. i'll ask DH tonight if he's pulled a tank from a classic prius. the first pic is the top of the tank, and the two holes you ask about are for a couple of sensors, i forget which ones he said they were. one is the sensor that detects fuel in the space between the bladder and the metal tank.
. . .
[/b]
Click to expand...

Ahhh, I see it now. I've taken out the rear seat of my NHW11 and it rests on top of the gas tank. Knowing which side the filler tube comes down clarifies that first NHW20 tank photo. I still don't know if the tank comes out via the cabin but that would be a sensible approach for the NHW20.

Given what the tank did to the air tool, I feel a lot better about crash-worthiness.

Thanks again, the photos are great. Good luck on the grant. My niece got a three year NSF grant.

Bob Wilson

Beryl Octet · Apr 7, 2007

<div class='quotetop'>QUOTE(galaxee @ Apr 7 2007, 10:53 AM) [snapback]419365[/snapback]</div>

beryl- fuel in space between tank and bladder. very, very bad. check out the thread discussing what happened to this car here: http://priuschat.com/index.php?showtopic=30786
[/b]
Click to expand...

Thanks, I usually don't try to squeeze every last drop in, anyway, just curious.

Oxo · Apr 7, 2007

<div class='quotetop'>QUOTE(galaxee @ Apr 6 2007, 11:41 PM) [snapback]419197[/snapback]</div>

here are the pictures. it was a hell of a lot of work, and the poor guy now is sitting next to me with an ice pack on his shoulder! enjoy!

[/b]
Click to expand...

Very useful and interesting - all 25 pics! I wonder how many hours it took Toyota's people to design it?

Am I wrong in thinking that European models of the Prius do not have a bladder? Is there any easily visible external evidence that a bladder is fitted?

the gas bladder: exposed!

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