Cadillac: transmission, vacuum modulator, vacuum hose

Question
I have a 81 seville 6 liter. what makes the transmission shift it is a front wheel drive 325 does it have a vacuum modulator.It shifts late and will not go in to 3rd It has a code of 88,30,70 on climate control.

Answer
Actually you need to perform a pressure test on the transmission.

However the steel line that goes from the intake manifold to the modulator tends to rust and get very tiny rust pin hioles in the line. try replacing the line with the same or larger diameter vacuum hose from the intake to the modulator and if it does not fix it. replace the modulator also.


tom