700R4 Vacuum Switch

[PrairieDrifter]

While driving, when you think it's locked up you can slightly hold the brakes and the rpm should jump up. It should unlock the converter if it's locked and you tap the brakes. This the best way to tell if you're getting lockup, since it's hard to tell if you're in 4th or lockup.

 

[Bruce Wingate]

@PrairieDrifter : Without a tach, I don't know if I'll be able to tell the change in RPM. I'll be doing a test run soon to see what I can tell

 

[PrairieDrifter]

@PrairieDrifter : Without a tach, I don't know if I'll be able to tell the change in RPM. I'll be doing a test run soon to see what I can tell

Its easily noticeably without a tach doing it this way. Youll literally be applying no brakes, just interrupting the signal to the trans.