I will speak to our trans rebuilder to verify for this trans. I believe there are multiple fluid feeds at the pressure regulator. One feeds the tc and cooler lines and another for lubrication and control devices.


I may be wrong, but I am pretty sure if you disconnect the upper hose, fluid will flow out the hose not the rad. I pulled the hose of an acadia and that's how it flowed. That is how the trans flow diagram shows it also.

 

I disconnected the lower hose and got fluid from the trans that's how I know 100% the upper is the return (same as my suburban)


Just concerned if I disconnect the upper and let it drain into a pail if something will be starved of oil because no oil going back to the transmission


Thanks

 

My 2 cents is to use the drain plug to get what you can, replace what was drained, drive it and repeat the process...its the safest and probably the easiest..

 

I spoke the trans rebuilder. the flow is in the direction you have said. What he said you could do is put the upper hose in clean fluid and the trans will draw it in while the disconnected lower hose can direct the old fluid out.