pleasants9

So I'm having the infamous headlight issue. Starting at the manifold I followed the vacuum all the way to the reservoir, that seemed to hold vacuum even after i turned the car off for a few seconds. Then it all seemed strong through both diaphragms for each actuator. Then when I took the hoses off the driver side headlight and plugged them, the passenger headlight worked fine. Yet, when I put the hoses back onto the driver actuator the passenger headlight wouldnt come up nor would the driver side. So I believe I can safely say that my problem is some sort of vacuum leak or loss of pressure in the driver side actuator. What I'm asking is should I replace the whole actuator, or should I look into just redoing the seals on there. Which is the best way to go?

0Willcox Corvette

Yes, if you isolate one side and it works, then use the same hoses with the other side blocked off you have found your problem.

If you do this you need to make sure to take one entire side out of the loop.

I would look in to just the seal and retainer kit for the actuator first. It’s a cheap fix and if it works it will save you a bunch of money.

If the diaphragm is blown out of the actuator then nothing will fix it.

Happy Holiday's,

Willcox Inc.

pleasants9

Thanks, I think Ill probably get the whole actuator to take care of the problem once and for all. Any tips on replacing the actuator?

Alan 71

Hi P9,
The accuator is pretty easy to change.
There are 4 nuts that fasten the 4 studs on the back of the actuator to the headlight frame.
Then there is a clevis pin, with a cotter pin, that goes through the actuator clevis and the link on the headlight mechanism.
In my 71 AIM it's on UPC12, Sheet A2.
Merry Christmas
Regards,
Alan

0Willcox Corvette

Yes, give me a few more minutes and I'll post a link for you on how to remove the actuator and rebuild it.

Here you go, I did this to quick and goofed up the links on the page. They are supposed to be hidden but they work and you should be able to figure it out. I'll do an edit on this later this week. http://willcoxcorvette.com/repairand...lp.php?hID=250

Willcox

pleasants9

Thanks All! Ill try and order that actuator tomorrow and get this little problem solved! Also, do those vacuum relays go bad frequently? my girlfriend bought me the two relays for the headlights before i got a chance to isolate the problem. Now that I have them should I replace them while i'm working on the headlights, or send them back and get back $100?

0Willcox Corvette

You might want to check the old relays first. See if they are leaking vacuum and then make decide.

Willcox

GUSTO14

Since you already have the new relays, I would suggest you test one of them on the drivers side circuit. (It won't damage the relay and you can still return them if they're not needed.)

Just remove each hose from the drivers side relay and connect it to the new one until all of the hoses are connected to the new relay. (Don't bother to fasten it to the car at this time, just set it in the area.) Now do an operational test of the headlights. If the headlights function properly, you know you need at least one new relay. And yes the relay's will malfunction much more often than a diaphragm will fail in an actuator.

Unless you just want to spend the money on a new actuator, I'm with Wilcox... For very little money, you can replace the seal and boot on the actuator and test it. The seal will leak long before a diaphragm will fail. You can look at the seal around the shaft and tell pretty easily if it is bad. If the seal is leaking, you can also usually hear the vacuum leak if you get close to it.

Don't confuse the dust boot...

which fails very rapidly, with the seal underneath...

The seal is much more durable than the boot, but it does fail... more often than a diaphragm...

Another test is to raise both headlights (manually if need be), then start the car with the headlights on, then push the headlight switch off. If both headlights close, the diaphragm is not leaking... but the seal in the front definitely is.

Keep in mind the relays are used to port vacuum to the front or back side of the actuator to raise or lower the headlights. When vacuum is ported to the back (engine) side of the actuator, it lowers the headlight. When vacuum is ported to the front side of the actuator, it raises the headlight.

If you were to raise the drivers side headlight assembly and then manually port vacuum to the actuator, it should lower the headlight. If it doesn't the diaphragm most likely is bad. With the headlight assembly down, if you manually add vacuum to the front port of the actuator and both the diaphragm and front seal are good, the headlight should rise.

Good luck... GUSTO