is there anyone with knowledge about 1st gen vintage air units the ones with the vacuum operated doors? a lot of guys say the don't work well, but they were around a long time before the electric ones came to be in factory installed units also. is there something I need to do specifically to make it work well? I am just in the mock up stage now thanx Tom
I am currently installing one of these that was never used. It is new in the box but an early design. I bought a vacuum reservoir and vacuum check valve to install and eliminate low vacuum when accelerating. You can find reservoirs on many GM cars at older salvage yards. These air conditioning units work fine. Many production autos up through the 80's used vacuum actuators from the factory. John
I believe some of he early units had vacuum operated servo's inside the evaporator. Troubleshooting and repairs would be difficult. VA Gen lV electric operated servos the way to go.
I've been running one of these in my sedan for 25 years. No problems. Use the juice can and check valve as noted above. I've heard that very hairy cams don't give you much vacuum. Somebody once made vacuum pumps for use on blower cars. If these pumps are still available it would likely help. I could help you with wiring or vacuum hose hookup if you don't have the original diagrams.
The Jalopy Journal
