I don’t think any of my other cars have implemented the use of vacuum to the extent that Corvettes does... Opening the headlights, whipper door, vents...etc. Is this unique to Corvette and why do you think they decided to use vacuum over electric motors or other mechanical means?

 

dumb idea. vacuum sucks!

 

Considering how advanced the car was in other areas I also wonder why "vacuum". My 1941 streetrod used vacuum! I also see a lot of aircraft design in the car having been in the military.
But vacuum? I would say less cost, but with all those actuators/tanks/hoses/valves/relays/etc....it seems to be the opposite.

 

Didn’t the c2 have electric motors for the headlights? Talk about downgrading.

 

Cost. Vacuum stuff is cheaper than electric stuff.

 

they had alot of issues with the electric headlights too. they changed rather than fix them. less expensive, less cost. Most of our problems come from crappy reproductions. Until someone steps up and makes good reliable parts again, its just going to et worse

 

My first car was a '68 Charger and it had vacuum operated headlight doors. Didn't work but that was the least of it's problems at the time. Cougars had them too and it probably wouldn't be too hard to make a list from that era.

Part of the fun for me was figuring it all out and making it work properly again. Electric conversions are solving problems I'm not having.

 

Good question Dave. Using vacuum was used for a lot of items on older cars, but it really shouldn't have been used on the C3s. I kind of get a laugh out of it though - our 427/435 doesn't have enough vacuum at idle to open the lights. I have to run the revs up to around 1000 to get them open, including the wiper door. Makes me smile when I do that. Probably because my body works a little slower now too.

 

Vacuum was used for accessory power source for many years. Cruise Controls and HVAC systems used it up to the 90's...some cars may still use it.

"Vacuum" is just waste 'energy' from your engine [which is basically an air pump]. GM and other makes didn't use vacuum primarily because it was 'cheaper'. It was simpler, more reliable [whether you believe it or not], and less expensive to repair.

Many C3's have original equipment vacuum motors/servos that still work flawlessly. The relays and other components with moving [and wearing] seals eventually start leaking. Not surprising after 20+ years of use.

 

I’m in the process of repairing the vacuum headlight system in my 77 and I’m having a ball doing it. I love to tinker with the different systems and figure out how they work. They’re really kind of fun to work on!

 

Wilcox and Ecklers has lots of great information and detailed diagrams for all C3 vacuum systems... they helped me fix my whipper door that wouldn’t go down...👍🏻

 

Thanks! I’ve used all of those resources too and I have to say, if they hadn’t been available I would have been really intimidated by the project. With the write up in the FAQ sticky in C3 Tech/Performance, the Corvette101 write up and the Willcox site it has been a fun project! Oh, and the MightyVac paid for itself on this. Anyone who works on C3s should invest in one. Well worth the money!

 

There were even more uses for vacuum in cars:

Windshield wipers. Yes, really even if they pretty much disappeared in the 40s or 50s.
Power door locks.
Automatic parking brake release (likely still used).
Fully automatic HVAC---in fact vacuum was the only way to do this until stepper motors and their controllers became inexpensive enough to use widely.

As others have said vacuum operated systems use "free" energy available with piston engines. It's this nearly constant and reliable source of vacuum that make it so practical. It's the vacuum source--not its utilization that is complicated and trouble-prone! Vacuum systems are simpler, easier to diagnose/repair, longer lasting and typically lighter than alternative systems. One great advantage is that "sticky", jammed or obstructed mechanisms won't cause any harm unlike electric motor systems that can overheat, burn up or even self-destruct. The vacuum components themselves require no lubrication, periodic maintenance, cooling provision or significant protection from dirt/grime/common engine fluids.

The inherent modulation (infinite variance) ability of pneumatic (air) systems (be they vacuum or pressure) cannot be dismissed. That's why vacuum operated cruise-control and automatic climate control systems persisted for so long.

And of course the only tool you need to diagnose problems is a simple, inexpensive hand vacuum pump.

Don't dismiss pneumatic (air) operated systems so lightly as they still have many advantages.

Now I just wish someone would make quality replacements for the vacuum motors and relays! The Chinese **** is just that and more likely than not to arrive leaking

 

DaveinSpain...

You just publicly published someone's efforts which have legal copyright. Unless that was "public domain" material, you are essentially stealing from the author. You probably don't see it that way...I know, just trying to help out....but, that's what it is.

 

Neither the excellent information nor the garbage information that many of us provide freely via free-to-access internet sites can be separated from copyrighted information where the author sells their product.

 

 

Oops, we’ll im in the music business and I wonder if you have ever copied or down loade music for free.... Most likely you have or someone you love has... Just sayin’

 

If the moderators feel they should delete the printed material I posted no problem.... I certainly didn’t mean any harm...

 

IMHO, vacuum systems were used because they are typically lighter and less complex to fix (yes, I said it) than their electrical counterparts. We get annoyed at vacuum leaks, but electrical systems have shorts and grounds along with more wiring to deal with. Yes, today the manufacturers are using the CAN bus to replace all the above, but this technology was not available in the 60's.

 

i think vacuum is good in small doses. heater controls, air doors, etc. still used today. but when pulling open big stuff. headlights, wiper doors... VACUUM SUCKS!