So I've seen it recommended frequently. I've done it a few times and the results have been universally good. I'm not questioning the validity, but I wonder about the absolute efficiency.
I can understand replacing the fluid in the pan. I can also understand replacing most of the fluid in the valve body, pump and cooler lines. That is directly fed from the pump, which is directly fed from the sump which is all clean and new. Over half my trans capacity is in the torque converter, which to me looks like a dirty great pudding basin. The fluid gets pumped in there, and the stuff that comes out goes out to the cooler. So I have a 8L capacity in the trans (~3 in the pan, ~1 around in general and), 4 of which is in the torque converter (which rotates and mixes like a washing machine).
So here's the question. When I pump 4L into that converter, how much of what comes out is old fluid? I'd *assume* that as the new fluid gets pumped in, it's constantly mixed with the existing fluid and it's that mix that comes out to the cooler, so short of pulling the converter and draining it there is no way to replace *all* the old fluid. Just a good proportion of it (in theory). The old proportional dilution conundrum, somewhat like the repeated drain and fill theory.
Am I missing something?
I can understand replacing the fluid in the pan. I can also understand replacing most of the fluid in the valve body, pump and cooler lines. That is directly fed from the pump, which is directly fed from the sump which is all clean and new. Over half my trans capacity is in the torque converter, which to me looks like a dirty great pudding basin. The fluid gets pumped in there, and the stuff that comes out goes out to the cooler. So I have a 8L capacity in the trans (~3 in the pan, ~1 around in general and), 4 of which is in the torque converter (which rotates and mixes like a washing machine).
So here's the question. When I pump 4L into that converter, how much of what comes out is old fluid? I'd *assume* that as the new fluid gets pumped in, it's constantly mixed with the existing fluid and it's that mix that comes out to the cooler, so short of pulling the converter and draining it there is no way to replace *all* the old fluid. Just a good proportion of it (in theory). The old proportional dilution conundrum, somewhat like the repeated drain and fill theory.
Am I missing something?