Fill or flush - Subaru Forester Owners Forum
Subaru Forester Forum
ebay search
Subaru Forester Forum
Go Back   Subaru Forester Owners Forum > Technical Forums and Vehicle Assistance > Transmission and Driveline
SubaruForester.org is the premier Subaru Forester Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 06-03-2010, 08:57 AM   #1 (permalink)
Fast & Dirty
Lifetime Supporting Member
 
SubieOutlaw's Avatar
 
Join Date: May 2008
Posts: 4,051
Location: North Shore
Car Year: 2009
Car Model: Forester XT
Transmission: 4 speed auto
Gallery: 0
Feedback Score: 1 reviews
Default Fill or flush

Hi

I am in the process of getting ready for the 48k service. The stealership says I should FLUSH the trans with new fluid.

The service manual I own for my 09 says nothing regarding flushing. It simply says drain and fill with the volume drained.

A local Subie service expert says he just drains and refills and doubts stealership flushes.

Thoughts and recommendations.
__________________
My 09 FXT Journal
SubieOutlaw is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-03-2010, 09:37 AM   #2 (permalink)
Forum Member
 
Join Date: Jan 2006
Posts: 375
Location: Katy, TX 77493
Gallery: 0
Feedback Score: 0 reviews
Default

Just recently I replaced all 10 qts in my 99 Forester by removing supply line to trans cooler(pax side connection to lower radiator). I filled trans pan w/ 3 qts, started engine, and pumped out 1-1.5 qts (only 10-15 secs), stopped, refilled trans pan, and dumped caught fluid. I repeated this until clear new fluid emerged from supply line at about 10 qts. Adjust fluid level by removing or adding to get to full cold position.

Above procedure leaves a small amount of old fluid from trans cooler and trans return line in the system. I thought of this after completing my work. Not sure how to recover this last bit of fluid, but it might be possible to suction out w/ vacuum hand pump or air gun vaccum.

If fluid is in good shape, say changed w/i last 30-50k miles and does not smell burnt or foul, drain and refill pan should be fine IMO.

good luck
__________________
See you down the ROW!
1999 Subaru Forester
TexasForester is offline   Reply With Quote
Old 06-03-2010, 09:44 AM   #3 (permalink)
has awakened!
Lifetime Supporting Member
 
2.5x_sleeper's Avatar
 
Join Date: Aug 2007
Posts: 19,054
Location: Newberg, OR
Car Year: 2007
Car Model: Forester Sports XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 37 reviews
Default

Last summer I had my trusted Subaru delership do a flush & fill on my '03 X & '07 FSXT. I opted to go with Redline synthetic ATF.

IMO, if you're going to do a "flush", do it before you have too many miles on your Forester. Both my Foresters are under 30K miles. If you have high miles & have never had a flush, I'd recommend just doing a drain & fill.

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
__________________
'07 FSXT - COBB Surgeline dyno Protune - Stage 1+
'03 X +AVO turbo kit = XT (son's)
'95 Neon Sport
2.5x_sleeper is offline   Reply With Quote
Old 06-03-2010, 09:52 AM   #4 (permalink)
Forum Member
 
Doc Samson's Avatar
 
Join Date: Mar 2008
Posts: 159
Location: Winchester, VA
Car Year: 2005
Car Model: FXT
Transmission: 5 spd
Gallery: 0
Feedback Score: 0 reviews
Default

Sounds like they are just trying to flush some $$$ out of your pocket, though it may be recommended for an AT. Peaty has this great write-up that also addresses the front diff for an AT - http://www.scoobymods.com/manual-tra...nge-t3091.html

Seems pretty straightforward to me, i.e. drain it and fill it. I'll be doing mine this weekend...
__________________
05 FXT w/ just a hint of mod
Doc Samson is offline   Reply With Quote
Old 06-03-2010, 09:56 AM   #5 (permalink)
Registered User
 
Papa_D's Avatar
 
Join Date: Mar 2009
Posts: 382
Location: Central Florida
Car Year: 2009
Car Model: Forester XT Limited
Gallery: 0
Feedback Score: 0 reviews
Default

This is often a hotly debated topic on many forums and usually comes down to the argument about not flushing with pressure due to the danger of dislodging dirt that may eventually interrupt the proper flow of fluid and ultimately destroy the transmission.

To me, it is OK to do a flush whereby only the normal pressure of fluid flow is used to evacuate the system such as the bucket method where new fluid is poured in as the old fluid is discharged into a separate bucket.

They supposedly have machines that only use the naturally occurring pressures although I don't know what they are called and from my understanding, many of the machines force feed fluid through the system which may dislodge contaminants which could be bad indeed.

In the end I have personally chosen to do fluid drain and fill but will do it far more often and if I do flush the tranny, I will definitely utilize a non pressurized method similar to what is shown in the video I posted or at least make sure that if a machine is used that it is not pressurized and doesn't cross contaminate my fluid with another type which can also cause serious issues but either way, the idea is to maintain a reasonably new mix of transmission fluid at all times.

Maybe someone who is more familiar with the fluid filtering or lack of it in this particular vehicle can chime in and give some more advice based upon dirt in the system and the harm it may cause without a full blown fluid flush, good luck with it.

__________________
09 FXT LTD, 4 SPD AT, NAV and AutoStart
Papa_D is offline   Reply With Quote
Old 06-03-2010, 09:56 AM   #6 (permalink)
Forum Member
 
Join Date: Apr 2009
Posts: 39
Location: Ottawa, Canada
Car Year: 2009
Car Model: Forester
Gallery: 0
Feedback Score: 0 reviews
Default

A flush is a risky thing. It runs the risk of picking up gunk that has settled in some nice out of the way nook or cranny in the tranny and dumping it somewhere you don't want it.

Same argument applies to engines.

Drain and refill ...

One of the other problems with the flush is that they can empty places like the valve body, which may cause airlocks or bubbles, and then they don't like to work. After rebuilding a valve body on a Renault I found out the hard way that an airlock in a valve body can produce some interesting results. Trying to go into two gears at once is cute.
sbrook is offline   Reply With Quote
Old 06-03-2010, 09:57 AM   #7 (permalink)
has awakened!
Lifetime Supporting Member
 
2.5x_sleeper's Avatar
 
Join Date: Aug 2007
Posts: 19,054
Location: Newberg, OR
Car Year: 2007
Car Model: Forester Sports XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 37 reviews
Default

Quote:
Originally Posted by Doc Samson View Post
Sounds like they are just trying to flush some $$$ out of your pocket, though it may be recommended for an AT. Peaty has this great write-up that also addresses the front diff for an AT - http://www.scoobymods.com/manual-tra...nge-t3091.html

Seems pretty straightforward to me, i.e. drain it and fill it. I'll be doing mine this weekend...
I love DIY stuff, but this isn't one of those things I want to mess with. The cost of having my dealership do the work really wasn't that bad.

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
__________________
'07 FSXT - COBB Surgeline dyno Protune - Stage 1+
'03 X +AVO turbo kit = XT (son's)
'95 Neon Sport
2.5x_sleeper is offline   Reply With Quote
Old 06-03-2010, 10:28 AM   #8 (permalink)
adc
Forum Member
Contributing Member
Supporting Member
 
adc's Avatar
 
Join Date: Aug 2007
Posts: 10,031
Location: Elizabethtown, Pa.
Car Year: 2008
Car Model: 2.5X
Gallery: 99
Feedback Score: 0 reviews
Default

I just do a drain and fill every 8K miles or so.
__________________
Be careful what you wish for.
adc is online now   Reply With Quote
Old 06-03-2010, 10:36 AM   #9 (permalink)
Fast & Dirty
Lifetime Supporting Member
Thread Starter
 
SubieOutlaw's Avatar
 
Join Date: May 2008
Posts: 4,051
Location: North Shore
Car Year: 2009
Car Model: Forester XT
Transmission: 4 speed auto
Gallery: 0
Feedback Score: 1 reviews
Default

wow.

it seems rather split. I think I will go with drain and fill.
Love the video.
__________________
My 09 FXT Journal
SubieOutlaw is offline   Reply With Quote
Old 06-03-2010, 05:59 PM   #10 (permalink)
Registered User
 
Papa_D's Avatar
 
Join Date: Mar 2009
Posts: 382
Location: Central Florida
Car Year: 2009
Car Model: Forester XT Limited
Gallery: 0
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by SubieOutlaw View Post
wow.

it seems rather split. I think I will go with drain and fill.
Love the video.
I couldn't find the two bucket method video where you have fresh fluid being sucked in at the same time it is being expelled which is what some of the Titan guys do rather than a "pressure flush" which is where I believe a lot of flush problems originate, that and also cleaning fluid additives and or cross contamination.

The two bucket method is similar to what you see in the video only you would detach the inlet and rest that hose in a bucket filled with fresh fluid, that way you don't have to worry about adding fluid, just watching for a color change.

If I do drain and fills, I will likely do four or five in fairly quick succession in order to eliminate most of the old fluid but maybe someone good at higher math can tell us exactly how many quarts of fresh fluid we will have to add to get a nearly complete fluid exchange.
__________________
09 FXT LTD, 4 SPD AT, NAV and AutoStart
Papa_D is offline   Reply With Quote
Old 06-04-2010, 06:59 AM   #11 (permalink)
Registered User
 
4str's Avatar
 
Join Date: Apr 2010
Posts: 83
Location: Owings Mills, MD
Car Year: 2010
Car Model: Forester 2.5X Premiu
Gallery: 0
Feedback Score: 0 reviews
Default

I spent several hours reading all those debates out there re pressurized flush vs drain + fill. Personally, I'm not going to ever do the pressurized flush.
__________________
2010 Forester 2.5x Prem, 4AT, Newport Blue Pearl
4str is offline   Reply With Quote
Old 06-04-2010, 08:47 AM   #12 (permalink)
Fast & Dirty
Lifetime Supporting Member
Thread Starter
 
SubieOutlaw's Avatar
 
Join Date: May 2008
Posts: 4,051
Location: North Shore
Car Year: 2009
Car Model: Forester XT
Transmission: 4 speed auto
Gallery: 0
Feedback Score: 1 reviews
Default

I think I will do drain and fill and few times within 500km.
I will then start to do drain and fill every 20k. The atf fluid from Subaru is $8 a litre. Pretty cheap insurance to spend $40 every 20k. Yes?
__________________
My 09 FXT Journal
SubieOutlaw is offline   Reply With Quote
Old 06-04-2010, 09:18 AM   #13 (permalink)
Forum Member
 
funkymonkey1002's Avatar
 
Join Date: Jan 2006
Posts: 9,011
Location: Boston
Car Year: 2004
Car Model: 2.5 XT
Transmission: 4eat
Gallery: 0
Feedback Score: 8 reviews
Default

Quote:
Originally Posted by adc View Post
I just do a drain and fill every 8K miles or so.
imo this is the best way to do it. A drain and fill every 7.5 to 15k (ever 2 to 4 oil changes depending on how hard you drive). This will keep good clean fluid in there all the time without wasting a bunch of good fluid by doing drain and fills in short succession (each time you do a drain and fill you're getting some of the new and some of the old and only about a third of the total fluid).


The "2 bucket" method of flushing would be the best, a lot of dealers have a machine that basically does that automatically. They call it a flush but its basically a fluid exchanger, which I wouldn't worry about using. I would however stay away from any pressurized flush or any that they use special fluids, cleaners, additives etc.
__________________
04xt/4eat, 16g, STI bits and bobs
funkymonkey1002 is offline   Reply With Quote
Old 06-04-2010, 03:40 PM   #14 (permalink)
Fast & Dirty
Lifetime Supporting Member
Thread Starter
 
SubieOutlaw's Avatar
 
Join Date: May 2008
Posts: 4,051
Location: North Shore
Car Year: 2009
Car Model: Forester XT
Transmission: 4 speed auto
Gallery: 0
Feedback Score: 1 reviews
Default

Just bought 12 litre of Subaru ATF
__________________
My 09 FXT Journal
SubieOutlaw is offline   Reply With Quote
Old 06-04-2010, 05:35 PM   #15 (permalink)
Registered User
 
Papa_D's Avatar
 
Join Date: Mar 2009
Posts: 382
Location: Central Florida
Car Year: 2009
Car Model: Forester XT Limited
Gallery: 0
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by funkymonkey1002 View Post
imo this is the best way to do it. A drain and fill every 7.5 to 15k (ever 2 to 4 oil changes depending on how hard you drive). This will keep good clean fluid in there all the time without wasting a bunch of good fluid by doing drain and fills in short succession (each time you do a drain and fill you're getting some of the new and some of the old and only about a third of the total fluid).


The "2 bucket" method of flushing would be the best, a lot of dealers have a machine that basically does that automatically. They call it a flush but its basically a fluid exchanger, which I wouldn't worry about using. I would however stay away from any pressurized flush or any that they use special fluids, cleaners, additives etc.
I would like to think that a drain and fill every now and again is the way to go but I wonder how the old fluid effects the new fluid with regard to any degenerative effects on the new fluid, any chemical engineers out there care to chime in?

I had a fluid exchange done to my Titan at the dealer but it was the non pressurized type and I personally knew the guy doing it for me and everything was fine.

In the end I see no difference between doing a non pressurized flush and simply running the transmission normally as far as any dirt working it's way loose and if people are careful and don't introduce air into the system or cleaning fluids, I have a hard time believing that a simple, non pressurized fluid transfer is responsible for any harm or malfunctions but on the other hand, a pressurized flush with cleaning additives seems risky at best.
__________________
09 FXT LTD, 4 SPD AT, NAV and AutoStart
Papa_D is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Subaru Forester Owners Forum > Technical Forums and Vehicle Assistance > Transmission and Driveline

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 06:15 AM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0