When bought the car last August the left headlight bucket would not retract when lights were turned off.
Have replaced the vacuum hoses, filter, check valve and rebuilt actuators.
When headlights are activated they both pop up but left headlight still will not go down. Any idea as to what needs to be done to make both function properly? Very frustrating!
Have looked at other posts but none seem to answer my problem.

 

see if this Willcox video helps

 

If you are not concerned with originality, I would like to recommend a kit from Richard454. It's an electric version that he offers for about half the price of the going kits. He also has a cool wiring harness that takes a lot of the guesswork out of the install.

 

Thanks, very helpful!

 

Thanks - will look into it!

 

Sounds to me like the pneumatic relay (mounted to the underside of the "nose" ahead of the radiator) is not working properly.

 

Thanks for your reply.

Not sure what the "pneumatic relay" is. Are you talking about the relay for the actuator? I have rebuilt the actuators and tested it along with the relays and they all function as they should. Have replaced all of the vacuum hoses except those that run thru the firewall to the override and light switch. Replaced the vacuum hose filter and check valve. Nothing has helped! Do not know what to do next.

Also, have watched the Willcox video on the headlights and followed it very closely.

 

Yes, that's what I mean. "Pneumatic" just means "air operated".

There are some bad hookup diagrams out there. There's a good one as well an an easy-to-understand explanation of how the system works here.

Have you double- and triple-checked the hoses at the relays? Center hose (yellow stripe) goes to the vacuum tank. Top hose (red strip nearest the relay head) goes to the rear of the vacuum motor. Bottom hose (green stripe) goes to the front of the vacuum motor. Be sure to install the top and bottom hoses on the relay first and then install the center hose as it acts to lock in all three of them. If you install the center hose before the top or bottom you won't be able to push the top or bottom hose far enough to prevent leakage.

I presume you have a hand vacuum pump/vacuum gauge. If so disconnect the hose from the rear of the motor on the offending side. Connect to the pump/gauge. Operate and see if you get vacuum with the headlamps "off". If not and given the fact that the other side works property you have a problem in the relay or the hose routing. Well..the rear of the vacuum motor body could have big but surely you've checked for that.

Remember that with the headlamps "off" and the override switch in the control portion (little lines) of the system is under vacuum. The control section portion of the system is completely separate from the operating portion. The control portion should absolutely hold vacuum for many, many hours. Such is easily checked using your hand vacuum pump/gauge by tapping into the control line at the check valve.

 

One other question:

Where did you buy your hoses? Doc Rebuild arguably sells the best sets as they're exactly the right size and striped just like the originals. I'm not sure about other vendors but do know from experience that you cannot buy hoses from the likes of Napa, AutoZone, etc. as they will not seal properly at connections. Even if you try to solve that problem using hose clamps such as used only on the vacuum motor you won't be able to install them on the relay

 

Test the 'actuators' and 'relays' again, Here's a good How-to:

http://www.corvette-101.com/vacuum.htm#top

 

Bought them from Willcox

 

Thank you

 

When my 80's passenger side headlight would go up but not back down again, it was the headlight actuator. When I used my vacuum tool directly on the rear fitting of the actuator, it would not lower the headlight. At least I think it was the rear one, so whichever one lowers the headlight, that's the one that didn't hold vacuum. I replaced the actuator and that problem was corrected. Driver's side was fine.

 

Thanks for your info.
Mine is the drivers side. I rebuilt both actuators and used the mighty vac on both the actuators and relays and both functioned as they should. Followed the video from Willcox. Don't understand why it is not functioning when car is running.

Update: For some reason, all of a sudden it has started to go down. It is taking about 25 seconds after the lights are turned off, but it is retracting. The right side goes down immediately. Doesn't make any sense to me!

 

I think I would have to put a vacuum gauge on the hose leading to that fitting to verify good vacuum. Is it possible the relay is working but not allowing proper vacuum/volume, or leaking?

 

How much manifold vacuum do you get with the engine idling? Perhaps a performance cam that greatly reduces vacuum?

Really sounds like a large vacuum leak or malfunctioning relay.

Did you try to move the hoses from one relay to the other? If you do and the other door is now slow you've identified the relay as the problem.