Auto trans fluid change with cooler, and flush it?

[jhawk]

Hi guys

I'm about to replace the fluid/filter on my '97 VT V6. I've done a trans fluid/filter change before, and know it's reasonably straight forward on its own. However, I've never done one on this sedan before, which has a factory-optioned transmission cooler on it (part of the tow-package I believe).

My question is, should I be doing anything different with regard to the trans cooler being there? Also, should I be trying to flush the whole system or something, and if so how would I go about doing that?

[2DIE]

I read somewhere not to try and flush the trans yourself because you can do damage.

If you were to attempt to flush it you would have to use trans fluid, somehow force it down the tans cooler line to come back out the other trans cooler line. Dont quote me on that as I have no idea how its done. I have read to take it to a auto trans specialist to flush it. I just change the fluid, never attempted to flush it.

[jhawk]

Yeah that's pretty much why I'm asking, hoping someone knows if it is that simple or not. Theorectically I'm pretty sure you could fill the trans with clean fluid, disconnect the return line from the cooler and run it till it comes out clean, but I'm not exactly 110% sure on that and don't particularly wana wreck something...

[2DIE]

Im not 100% sure either but someone will pop up and answer how to do it correctly if they know how.

Pretty sure the torque converter holds a lot of fluid too that would be very hard to try and flush without dropping the auto out.

Did a google search and clicked on about 5 diffrent pages. This was the most useful one.

How to flush an automatic transmission yourself. - DSM Forums

Although there is people disagreeing with each other about how to do it.

[shadetreemechanic]

Back flushing as performed using a flushing machine is not recommended by GM. The only service method for the trans is by dropping its pan. However I've done a partial flush on mine twice to refresh burnt oil (didn't drop pan to change filter) as follows:

Remove thermo fan. Disconnect the bottom trans cooler line going into the radiator, that's the IN (top is OUT which I'm assuming goes to your external cooler from there since I don't have the optional cooler)
Stick the dangling line into an empty 5L oil bottle. Set the trans to P and run the engine. Watch the container fill up rapidly and shut off when enough fluid is out. Don't let it run till dry. Reconnect trans line and reinstall the fan. Refill with the exact amount you removed. Switch on the engine and check the dipstick level.

4L60-E can take about 8L (or 11L depending on torque convertor size) when dry. Service capacity is 4.8L by removing the pan.

[vxcalais_01]

Apparently the these transmission, most wear is in the beginnings, when bands, valves wear in etc. So doing a full flush is important somewhere along the line. Get your 8 litres or so of new fluid. Undo the return line that goes from radiator into transmission. Get a container and fill with 1 litre water. Mark on it where 1 litre is and empty it. Now add 1 litre to the trans through the filler tube. Start car, takes approx 15 seconds to fill a litre. leave it in Park mode. Once you expel a litre you add a litre and by 7-8 litres i will stop running out dark and be clean. This removes all the fibres and worn parts. Doing this every 2 years negates the need for regular pan filter changes. The sponge filter in the pan only catches large debris and can even be pushed out to every 2 years. What i have also installed on the return line is a magnefine filter.Dual Filtration

For $30 it filters better than the pan gasket. Easy to install as well. Once flushed and a magnefine installed, 50-100,000k changes should be fine.

[delcowizzid]

those magnifine filters are great ive seen them turn brown fluid red again

[2DIE]

Just looked up magnnifine, no price info in Australia even though they are made here. Saw an American website selling them for $16 each so I assume it wouldn't cost much more here.

Where would you get them from without contacting the company directly, for example Super Cheap, Repco, Sprints ect?

[acarmody]

The dealers are there on their website, here, Contact Magnefine