I'm ( hopefully) fixing trans fluid leaks when I noticed a small diameter hose or tube just laying there with a screw plugging it. What is it?
.

 

That should go to the modulator valve, just below it.

 

Speedtoys ,I replaced the line to the modulator with the white one . I don't remember plugging a line that wouldn't need to be because it is disconnected at the other end. Thank, Doug.

 

well OK ,
so someone plugged that line.
it should go to the modulator,
the other end is connected to a metal line that runs up the TT,
and then at the base of the front bell housing there is another rubber line,
thats connected to the 7 way splitter

 

Well, I just asked the friend who helped me sort some things out early on and he remembers plugging the line as I tested the other end with a mighty-vac to run down vacuum leaks. One great big "duh" moment! So as usual you guys really know your stuff!

 

Isn't that the same line that is plugged to firm up shifts?

 

That's the first I have heard of this. The proper way to adjust shift pressure is to adjust the modulating pressure by means of the little pull out handle on the modulator. I wonder what problem was masked by plugging this line...?

 

I would NOT recommend removing the line to firm up shifts - I knocked the line off once and shifting at anything less that wide throttle openings almost broke my back!

****A cautionary note in case someone finds this post and thinks this is a good way of achieving firmer shifts.****

Myles

 

Actually what I discovered was the old line didn't hold a vacuum so, as I now recollect , I ran a new line.

 

When the metal vacuum tube located on top of the TT plugs up over time some people run a secondary flexible hose (by-pass) from the transmission along the metal fuel lines on the PS to the front in order to have vacuum to the modulator.
Later on when there is time when the TT comes out for service and the original metal line get blown out or replaced they opt to leave the secondary line in place just in case and plug the ends.