5EAT Power flush

[Boost]

Hi guys,

A friend with a gen4 5 speed auto wants to do a power flush on his tranny.
Can someone reason a workshop in Sydney capable of doing a good job and what sort of cost is expected and the type of oil to use ?

Thanks!

[Sean82]

DIY; I recommend getting 20L of ATF for it. Takes about a 1-1.5 hours to do. Needs two people realistically.
You'll also need to be able to access the trans drain plug (needs an 8mm hex head/Allen key to undo it), and to access the lines / hoses for ATF near the radiator


- Drain the oil pan and fill tranny with fresh fluid

- Disconnect the hose from the return hard line, the rear of the two near the water pump/radiator hose:


- Attach some ⅜" (10mm) hose to the hardline and plug the end, this will stop too much air being sucked into the system.

- Feed the return hose into a bucket, preferably white with graduated marks so you know how much is being pumped out.

- Get about 30-40 cm of ⅜" (10mm) hose and shave the outside off one end tapering it


Use this to extend your ATF filler. Then shove a small funnel in the other end. Alternatively, just find one of those flexible ones with a long spout that fits into the ATF filler.



- Replace the drained fluid with the same amount of fresh

- Start the car and let idle with one person filling as fast as possible (it's not very fast) and the other monitoring what is coming out of the of the tranny; you won't be able to leave the car on for more than a minute or two each time as the fluid is pumped out much faster than you can replace it; this is where the bucket with marks for volume on it comes in handy; so you know how much you've drained and how much needs replacing

- Continue this process until you start to see clean, fresh ATF being flushed through; if it's anything like the few times I've done this, it'll be bloody obvious

- Once fresh fluid is coming out, replace the removed return hose and fill the trans to appropriate level.

Depending on how bad it is, and how much fluid you have available, you can also cycle through gears (foot slammed on brake!) to help circulate the fluid a bit. I usually do this when the fluid is starting to become more translucent.

All up, if you have a way of raising the car, or getting underneath it, and can spare the time, it should cost about $200. I get Penrite ATF-FS in 20L drum from Autobarn for $189. Then another $10-20 in random bits (funnel, bucket, etc.). Works out a lot cheaper than any place in Brisbane I've found that will do a similar thing (about half of most workshops and about a third the price of the only Subaru dealership that will do it up here). I spoke with the foreman at City Subaru in Brisbane and he says while the power flush done by a workshop is better, this method will get "FKN close to a 100% flush".

HTH
Sean..

[Sean82]

I should mention, that when I say "cycle through the gears" I mean just go between D and R a few times.

And I've done this flush method four times; twice on 4EAT and twice on 5EAT. The improvement to shifting with clean fluid in is pretty astounding...
(EDIT: assuming you have bad fluid in the tranny and not some other, deeper-seeded issue causing your shifting problems)

Sean..

[Boost]

Hi Sean,

Thanks for your DIY instructions.
A couple of questions.
The red arrow in the picture I'm assuming is the return hard line which returns the oil back into the tranny.
From what you're saying, if you disconnect the rubber hose connected to this hard line and plug up hard line, how can fluid from the disconnected rubber hose drain into a bucket because its the return hose ? Shouldn't you be disconnecting the factory rubber hose and attaching a longer hose to the return hard line into a bucket ?

OR

do you mean the hard line with the red arrow is the feed into the cooler which then makes sense to plug it up and put the disconnect rubber hose into a bucket and plugging up the hard line to prevent air sucking in cause the other rubber line will be the return into the tranny ?

I hope that makes sense ?

cheers
Steve

[Sean82]

Hi Sean,

Thanks for your DIY instructions.
A couple of questions.
The red arrow in the picture I'm assuming is the return hard line which returns the oil back into the tranny.
From what you're saying, if you disconnect the rubber hose connected to this hard line and plug up hard line, how can fluid from the disconnected rubber hose drain into a bucket because its the return hose ? Shouldn't you be disconnecting the factory rubber hose and attaching a longer hose to the return hard line into a bucket ?

OR

do you mean the hard line with the red arrow is the feed into the cooler which then makes sense to plug it up and put the disconnect rubber hose into a bucket and plugging up the hard line to prevent air sucking in cause the other rubber line will be the return into the tranny ?

I hope that makes sense ?

cheers
Steve

The indicated one is the one back to the tranny from the radiator.
Disconnect this hose from the hard line only when pumping the ATF out (i.e. the car is started). It will be pumped out

Because it's pumped out, you can only run the car for a minute or so like I said; otherwise you risk letting the ATF level get too low.

I've got a video somewhere, I'll see if I can dig it out

[Sean82]

From when I did my SH Foz (5EAT).
You can see how aerated it is in the bucket because we didn't plug the second hose and it's sucking air in.

[kiahatsiu]

Great answers. Found that interesting.

[Out6ack]

I had to Google what a power flush was!!
I had my 5EAT serviced at an auto trans joint 13000km/12mths ago and I HATE knowing that this definitely wasn't done.
They didn't even change the trans oil filter tucked in behind my battery (I've since changed it myself).
So the dilemma now is, should I do a flush now or could I leave it for another 12mths? It's not long had a service after all..
I'll have to go back through records of any previous major services and see if it was done then, but it sounds like any mechanic would've charged a bomb so I'd definitely remember that!
Damn I wish I knew about this 12mths ago.
Live & Learn..

[Sean82]

I had to Google what a power flush was!!
I had my 5EAT serviced at an auto trans joint 13000km/12mths ago and I HATE knowing that this definitely wasn't done.
They didn't even change the trans oil filter tucked in behind my battery (I've since changed it myself).
So the dilemma now is, should I do a flush now or could I leave it for another 12mths? It's not long had a service after all..
I'll have to go back through records of any previous major services and see if it was done then, but it sounds like any mechanic would've charged a bomb so I'd definitely remember that!
Damn I wish I knew about this 12mths ago.
Live & Learn..

Check the colour of your fluid, if it's a nice translucent red, you're sweet
If it's a slight brown, I'd be taking the time to do a full flush. I swear by them for minor rough shifts. Even on my 253,000 km-old auto the recent flush worked wonders. It's not as smooth shifting as my Foz was (but that was the revised 5EAT and only had 67,000 km done), but it's a lot better, especially when cold.

[Out6ack]

Sounds like good advice Sean, thanks mate.
I think I'll start shopping around for 20L of ATF-FS and do it right regardless. It'll just bug me until I do..
I was back at the auto trans shop last week getting them to fix the sump thats been leaking ever since their service and to confirm that they hadn't changed the trans filter, so ive really got no faith in their work..
Good thread Boost.
EXCELLENT instructions Sean.
Cheers