Tehfitm8

Hello all! Need some advice the previous owner of my 1992 rs 305 camaro bypassed the transmission cooler by cutting the pressure and return hoses and connecting them together, this resulted in some terribly black burnt transmission fluid, so in response to this I am preparing to have the transmission rebuilt but for the time being I'm replacing the lines, fluid, filter, and gasket. And I was just in a dillemma as to if I should change out the 5 quarts of fluid in the pan, or should I just completely flush the system with 11.5 quarts of new fluid?
I've had someone tell me to do 3.5 quarts new fluid and 1.5 quarts old fluid (reminder my fluid is burnt) put about 400-500 miles on it then repeat that exact process, everyone is telling me something different and I need help! Thanks for your response

Tehfitm8

Oh and by the way it's an automatic 700r4 transmission

sofakingdom

iTrader: (1)

If the fluid is destroyed, you need to get EVERY SINGLE DROP POSSIBLE out of it.

Don't expect miracles: the reason the fluid is black is because THE PARTS got so hot inside there, they burned it up; all the rubber seals and such are probably crumbled to dust, and likely the clutches are ruined too.

The pan holds around 5 quarts or so. Another quart or thereabouts is in the various places inside the trans that it goes; clutch pistons, accumulators, etc. The rest is in the torque converter and cannot be "drained". Only way to get it out is to run the car with the cooler lines disconnected, catch the old fluid as it is forced through the converter and out the one cooler line (5 gallon bucket under the line or the like), and keep pouring new fluid into the fill tube to replace what is expelled.

Frankly though I think you're wasting your time money and effort on a hopeless cause, but, good luck with that.

Tehfitm8

Awesome, great response thank you for the honesty!! On that given note should I just go ahead and replace the lines then have the transmission rebuilt?

Night rider327

iTrader: (13)

Yep... The ATF is not black cause it's burnt.. It's black cause the clutches (frictions) in trans is burnt and wearing. The black you see if your clutches.

You can not run an auto trans with out a cooler.

If you drop the pan you will see thick black goop in bottom of pan with shiny specs in it.

Your best bet is to have trans rebuilt, replace torque converter, and flush the lines out

Tehfitm8

Perfect well thanks very much for saving me some time and money!! I appreciate all of your input friend!

sofakingdom

iTrader: (1)

And of course, hook a fluid cooler back up to it, so it doesn't burn itself up again.

Jacques101

Busy rebuilding the TH 700r4 on my 1984 - what fluid did you use? Do I have to use stock ATF, or can I upgrade to Dexron 3?

Night rider327

iTrader: (13)

All dexron/mercon is backwards convertible.

So if your trans uses say dextron II, you can use dex III and work great... But if your trans uses dex III, you can't use dex II in it.

You will be fine with any dexron/mercon sold in the stores. All of it will work with your 700r4.