This is educating explains  how the vacuum system works
 

|UPDATED|8/9/2013 9:39:33 AM (AZT)|/UPDATED|

I've mentioned this before but the best way to troubleshoot the Vac. sys. both the wiper and HL. sys. is to go Harbor Freight and buy a electric vac. pump, hook it to the main Vac feed line that comes out of the rear of the intake manifold and plug in the cord, now you will have constant vac to the complete Vac Sys. without starting the car, HL's, wipers, vent doors, heater controls, relays, etc, work all the sys. controls listen for leaks, they are hard to hear with the eng. running, eng will also run better after you fix any hidden vac leaks.............................just checked Harbor Freight those pumps have gotten kinda spendy, better to rent one, Air Conditioning Vac pumps will work.

|UPDATED|8/9/2013 10:09:44 AM (AZT)|/UPDATED|

That's a good tutorial there. Note that ya'll can download it in a PDF format if ya want....I would suggest it would be a good idea to have a copy handy in your own tech libraries...

Here Is another good topic on the wiper operation

Anipseoj. JOE suggested a vacuum pump to do testing . Got one from harbor freight air operated so I can vary the vacuum HOW MUCH VACUUM SHOULD I SUBJECT THE SYSTEM TO ??? Ended up having to drill out buba's broken and striped bolts, installed helicoils and alls well . Repainted and cleaned up the wiper channel and ready to test Thanks, BIg Al

|UPDATED|8/16/2013 11:26:36 AM (AZT)|/UPDATED|

depending on what kind of shape your motor is in  it should be puttin out about 15-20+ HG of Vac. , check the instructions but I think the HF air powered Vac pump puts out about 28 HG.



|UPDATED|8/16/2013 2:35:40 PM (AZT)|/UPDATED|

Your LT-1 won't be puttin' out 15 HG of Vac.  Mine pulls about 11.

 

B.A., how did the pump work, for the sake of everyone I threw in the 15- 20 #, my motor has been bored and the compression raised it idles about 14-16HG if I remember right.