There are no vacuum lines running to the automatic transmission.
engine vacuum or direct into the intake.
That transmission is all computer controlled. No vacuum lines on it.
on some cars there is a automatic transmission modulator valve that tell by vacuum when to shift gears. If that valve goes bad you will get tranny fluid in your lines.
On the underside of the hood near the front there is a diagram of your vacuum hoses and where they go.
You would need a ported source for the distributor, constant for a pcv valve, constant for power brakes, and constant for transmission modulator if automatic.
It depends on which distributor and transmission you have. The stock distributor has one vacuum line going to it. An autostick transmission has one line. If you have a manual transmission and a Bosch 009 distributor like most people do, you have no vacuum lines.
Vehicles with an automatic transmission may have lines that carry transmission fluid from the transmission to a separate tank on the bottom of the radiator.
There are more than 14 vacuum lines on the 1997 GMC. Most of the vacuum lines originate from the air intake system or the transmission.
Pressure and return lines that goto radiator and or transmission cooler to keep the ATF chilled off.
There should be a diagram of the vacuum lines on the passenger side shock tower.
those 2 lines are oil lines from the automatic transmission to the radiator .these allow for the transmission oil to be cooled
There should be a diagram of the vacuum lines on the passenger side shock tower.