1982 headlights vacuum problems

[82RL]

I am try to track the down the problem with my headlight not raising up. The main vacuum hose coming out of the engine goes to a filter and then to the metal check valve. Coming out of the check valve on one side( the side going to the lights) the vacuum registers around 18-20, On the other side (the side going to the firewall) it registers 5. Is this normal or is the check valve bad? I checked with the light turned on and off. I am a beginner at all of this so I appreciate your help.

 

[Yoda]

82,

Here are a couple items you'll find very interesting and may provide you with some answers to your questions:

This one is taken from the L81VetteRegistry Tech section:
Section III ~ HeadLights: Item “B”
and this one I found from doing a search here at CACC in the C3 forums usingvacumm for a key word.
Head Lights

BudD

 

[Bob Chadwick]

It doesn't seem right that there is such a vacuum difference. They are fairly cheap, I think the shipping was more than the valve, and you might want to consider replacing it before trying anything else.

Bob

 

[82RL]

Rare 81 and Bobchad that is exactly the information I was looking for thanks a bunch.

 

[82RL]

I think I have narrowed down the problem to the actuators. Since the car is 20 years old and set up for a year, I am thinking about replacing the actuators instead of replacing the seals,eventually replacing the whole system with new parts. My question is are all the actuators and relays sold by Mid America, Corvette Central, Ecklers, etc. the same or is one better than the other. Is there a brand out there that I am not aware of that is better?
Thanks

 

[Yoda]

The aftermarket vendors you've listed are good. For the C3's I've found a couple of vendors to be very good, Rik's Unlimited Corvette Parts and Volunteer Vettes Products, Inc.

Happy shopping

BudD

 

[Bob Chadwick]

I've found The Last Detail, www.tld-corvette.com, to have good quality and generally, better prices.

 

[vmrod]

Before you go buying a lot of expensive stuff, I would check over the entire system carefully. Is the check valve still functioning? (If you can suck through it one way, but not the other, then it's still good.)

 

[82RL]

Yes I have checked system even swapped out the check valve with a friend of mine. I have vacuum all the way to the actuators( after replacing the reservoir). Again let me mention the lights will not raise up but they go down when the switch is turned off. Do you think a seal kit would be worth trying before I buy a new actuator.

 

[vmrod]

If they do not go up, then how do they go down? (or do you manually pul them up first?)

 

[Bob Chadwick]

I understand the system is a combination of springs and vacuum. Are all of your springs in place?

 

[82RL]

Manually pull up,with the lights on and motor running. Turn the light off and they go down by themselves.

 

[vmrod]

...there are also either 1 or 2 vaccuum relays too. My headlights are working (or not working) just like yours. I am very sure that everything is hooked up correctly too.

I remember reading a very good troubleshooting guide for the vaccuum relay(s) and the actuators. The trouble-shooting required only something to block off a vaccuum line.

I'll do a little research and report any findings.

 

[82RL]

Rare 81 has good information listed about trouble shooting. I used this in checking my system. Check it out.

 

[82RL]

All the springs seemed to be ok. If you watch close when you turn the light switch on you can see they try to raise, maybe moves about 1/4 inch.

 

[vmrod]

yeah...but what I was looking for was very practical.

It was something like....remove lower hose from this and plug. remove upper hose. Manually lift headlights. If it is difficult to raise, then the diaphram and seals are good. If you hear a hissing sound, then the seal is bad.......(lots of good stuff like that.)

Once I get back to working on mine again, I'll make a troubleshooting guide like that. I hate listening to people telling me to replace 'everything', without truly knowing if the part is bad or not.

 

[vmrod]

Since you have a vaccuum gauge, you could measure the primary vaccuum at the relay. (It's the center of the 3 hoses). If that is OK, then measure the vaccuum coming out the lower port of the relay. (it raises the lights.)

...well, I'm gone for the rest of the day. Maybe I can help more tomorrow.

 

[82RL]

I checked the relays they seems to be ok.

 

[82RL]

I bought the seal kits for the actuators from Eckler's and installed them this weekend. The headlights now will raise up although slow. I did notice that while I had the actuators off the ports where you connect the vacuum hose was pitted pretty bad so I will replace the actuators. While driving the car I noticed the wind would lift the lights up and when I slowed down they would go back down. ( lights were not turned on when this happened). Could age of the actuators cause this and also cause them to raise and lower slowly when the lights are turned on and off?

 

[vmrod]

I know that vaccuum not only raises the lights, but also lowers them. (that relay is what dictates the action) If your relay(s) are good, then I would suspect the actuators.

The relay has a single hose coming from the top. This is the signal vaccuum. A vaccuum signal will raise the lights. Then there are 3 hoses that connect next to each other. The middle of these should have a strong vaccuum (it comes from the vaccuum tank). The upper hose is the vaccuum line which connects to the actuator and will make the lights go down, and the lower one connects to the actuator and makes the lights go up. I think that testing these hoses is the critical part of determining where your problem is.

I hope you can solve the problem.