newbie2vette

I am helping a freind with her 1979 with L82/automatic trans. It does not want to shift as it should, in order to drive it I manually shift to low and work my way to the final drive in order to drive without feeling like it is still in first or second.

I looked around the transmission, I remembered this trans have a vacuum modulator to assist with shifting properly. I found it at the end of the trans, but the hose was disconnected. I hooked it back up, it still does not shift properly. Can someone assist me where it should be connected on the carburator. She had a re-built carb put in (quadro jet). The quality of the work done to her car I question if the vacuum line for the trans is in the proper vacuum port on the carb. Thanks in advance.

Ganey

It was connected to the intake vacuum, there is a 'tree' at back pass. side of intake.

newbie2vette

any chance you have a photo of this fitting? The only "tree" I saw back of the intake is where the vacuum line for the head lights and among other line. One side of the fitting is capped off. The vacuum line for the trans, is it a constant vacuum?

1Fordman

Trans modulators hook up to a constant vacuum source.

DRIVESHAFT

Yes, it needs to be full time manifold vacuum.
Unless its been altered, your vacuum modulator line will be a metal tube except for a short length of vacuum hose on both ends.

newbie2vette

Thank You everyone for your help, you just saved my friend some $$. I did find the "T" fitting behind the carb with one of the port capped off. Yes the vacuum was majority a steel tubing with several inches of vacuum tube on each end. I hooked it to the port with the cap on it, took it for a drive. It shifted smooth. Again thank you and my friend thanks you.

Ben