I have the ISSPRO trans temp gauge. I just received my replacement line from Diesel Manor with the fitting in it to install the probe. Looking under the truck, it appears I'm in for a trans fluid bath. Is this true?

 

I just did it last night myself. I would estimate that I drained/lost about 1/2 quart at most. The line on my '06 is high enough that all you really lose is what is in the line and a bit out of the upper connection at the cooler. I removed the lower connection first and drained the line into a bucket. I then installed the new line in the lower location, then I removed and replaced the upper connection. I then replaced the lost fluid with new ATF-4 and all is well.
Good luck

 

Thanks for the info. As soon as my FASS gets here, I'll hook everything up. I painted my "A" pillar yesterday and got all the gauge wires ran thru the dash. All I need to do now, is install the FASS and hook up my gauges.. WOO HOO

 

On a '98 I lost four quarts of ATF while swapping lines.