About to change fluid on my 4L65E for first time..

[daman]

Originally Posted By: Tucson Five-O
Sorry for the confusion. When I said flush I meant I would disconnect the return line (which one would that be? I know it's the cooler of the two and does it have to be that one?) put a section of clear vinyl hose over it and drain into a bucket with the engine running until I see some air pockets appearing.
This would be my preference but it scares the you-know-what out of me. I'm worried about damaging the transmission. And is there a fill plug or do I refill through the dipstick? To be honest I haven't checked to see if this car has a dipstick. I'm not as anal with the transmission as the engine but that's going to change.

Thanks,
Gary


No problem i hear ya..

if unsure what line is what just put a hose on both stick in bucket and start engine once you see what line you need shut off engine and use that line,i'll tell ya over the many years of doing the line flush i run the engine till the oil stops flowing then a few seconds after that,NEVER a transmission problem.

Do your pan and filter change once buttoned back up fill trans with say 8 qts or half of factory spec.

have hose in a qt bottle have a helper start the engine once the qt is full stop the engine,pour 1 new qt into the trans,repeat above have helper start car when qt bottle is full stop engine add 1 qt back,do this for 4-5 qts and watch the oil get cleaner every time coming out.

if you have the dipstick less trans you'll need a funnel to get to the fill hole,usually a red cap on the trans driver side top.

 

[Tucson Five-O]

Now I'm confused daman! I thought that flushing the fluid with the engine running would completely drain the transmission. How much fluid does it take using your method? Wouldn't your method, with the half filling and the siphoning off one quart, refill a quart, siphon a quart, etc. waste a lot of new fluid (@$6.69/qt. I might add ;-) )?

Thanks,
Gary

 

[SteveSRT8]

if you do a cooler line flush you only empty the pan.

Since you only move the fluid through stock pathways using the vehicles own pump there is no damage to ANYTHING, and no debris will be deposited anywhere.

You'll pump out the pan capacity each time, it takes two or three repetitions to get clear fluid in the line, then you're done.

This is NOT a substitute for changing the filter.

 

[daman]

Originally Posted By: Tucson Five-O
Now I'm confused daman! I thought that flushing the fluid with the engine running would completely drain the transmission. How much fluid does it take using your method? Wouldn't your method, with the half filling and the siphoning off one quart, refill a quart, siphon a quart, etc. waste a lot of new fluid (@$6.69/qt. I might add ;-) )?

Thanks,
Gary

Yea it's hard to type what i mean on the keyboard here..

running the engine with the line off till fluid stops gets all but the TC oil(witch is allot) and some in the lines,cooler,i do that first before i drop the pan to do the filter. Once the filter is done and pan is back on then i start the fluid exchange as posted above.

and yes the bad part is you'll waist some fluid,BUT you'll have 100% clean in once done and your good for 30 to 50,000 or more depending on your application and oil brand.

i use Dex 6 @ 50,000 mile OCI, and flush through 3-5 qts depending on how dirty the old oil is and the vehicle,some have bigger systems then others.

 

[Tucson Five-O]

So what I'm hearing is, since only the fluid in the pan gets flushed through the line then there shouldn't be any difference in the end if I just drop the pan, get the 7 quarts out, put the pan back on, refill with 7 new quarts, drop the pan, dump, pan back on, refill, etc? If I had a drain plug on the pan and drained and refilled two or three times, other than the filter issue would I get the same end result? It sounds like it. The cooler lines are very short and are formed. I didn't want to bend a line or strip one of the fittings. And if I'm basically doing all this draining and refilling then why not drop the pan, change the filter and do two more pan drops and refills the next two times I change the oil (~10K OCIs) and call it good?

Just thinking out loud,
Gary

 

[Tucson Five-O]

Dextron VI is supposed to be good for 100K normal service. I think daman's method is technically the best but at what cost--18-20 quarts? At $6.69/qt.?

I'll keep eveyone posted as to what method I ended up using.

Gary

 

[mechanicx]

When Daman said he unhooks the cooler line before taking the pan, then true only the pan oil will get removed. This makes taking the pan off to clean and change the filter much less messy. I'm a little leery of running it till the pan starts running dry, but if you shut it down the minute the line starts "spitting air" then it should be OK.

NOW, when you put the pan back on and add new fluid and then run it, you will be pushing the old fluid in the converter out with the new in the pan. Do you see why you now get a near complete change using less fluid and a lot less trouble and mess? I think 13-14 qts (just over total system capacity) should get you seeing clear fluid at the cooler line plus retopping up the fluid.

When you unhook the lines to flush, you might find that it's easiest to do it at the radiator and to use the pressure line. This is really just as good. Sometimes there is no flare nuts at the transmission but usually there are at the radiator but not on some late models. Use a good penetrating oil like PB blaster and a line wrench and the lines should come off without problem.

 

[sciphi]

I've always siphoned off ~6-7 quarts of old fluid through the dipstick (which an 08 Impala "ought" to have), dropped the pan, cleaned the magnet, changed the filter, buttoned it up, then refilled with ~7 quarts of new ATF. AFter that I unhook a cooler line (that goes to my B&M transmission cooler) and flush out 2-3 quarts at a time, making sure to top off what got flushed out. When I go through 7 quarts, I stop and top off the transmission.

I've never heard of a PCS failing due to a flush. Mine's already packing it in, but that happened well before I flushed my Buick's transmission.

 

[mechanicx]

Siphoning out the pan and then running another 7 qts 2 quarts at a time is probably the easiest/safest way to do it.

 

[daman]

Originally Posted By: mechanicx
When Daman said he unhooks the cooler line before taking the pan, then true only the pan oil will get removed. This makes taking the pan off to clean and change the filter much less messy. I'm a little leery of running it till the pan starts running dry, but if you shut it down the minute the line starts "spitting air" then it should be OK.

NOW, when you put the pan back on and add new fluid and then run it, you will be pushing the old fluid in the converter out with the new in the pan. Do you see why you now get a near complete change using less fluid and a lot less trouble and mess? I think 13-14 qts (just over total system capacity) should get you seeing clear fluid at the cooler line plus retopping up the fluid.

When you unhook the lines to flush, you might find that it's easiest to do it at the radiator and to use the pressure line. This is really just as good. Sometimes there is no flare nuts at the transmission but usually there are at the radiator but not on some late models. Use a good penetrating oil like PB blaster and a line wrench and the lines should come off without problem.

^^^^^Right


i use around 3-5 qts to flush depending on the application(transmission size,TC)by then that usually is enough to get the fluid running nice clear.