Headlight trouble.

[lheindrich]

My left front headlight does not come up without me manually assisting it. I did some troubleshooting and all of the hoses are good without any leaks. Unfortunately my holding tank does have a leak so I bypassed the tank and just connected the supply line that went into the tank to the two feeder lines that went to the headlmp relays with a T fitting. Will this break anything until I am able to repair the leaky holding tank? The left headlight comes up and down now but slower than the right headlight could this be a faulty left headlamp relay or the actuator has a leak? I guess I have mor troubleshooting to do. Also it is difficult to get to the leaky supply valve on the holding tank is it possible to use a coffee can holding tank used in later C3's.

 

[JRGAPI]

I had the same problem with my 74. I located some actuator rebuild
kits and rebuilt them. Everything works fine now.

JR

 

[duke94]

Could be the shaft seal on the actuator. You can buy replacements.

Gary

 

[KOPBET]

If you think the relay might be bad (which it probably is), simply switch it with the other side or route the hoses to the other side. Simple check.

You don't need the tank for normal operation unless you plan on opening the headlights with the engine off (good luck with that anyway).

 

[Jimmy C]

Go to: http://www.corvette-101.com and to the vacuum section on headlights.

How the website was incorrect (corvette 1975) I have no idea!

 

[lheindrich]

You were right. I fixed my leaky holding tank and I made sure the relays are ok. I tested the vacuum reading from the green hose with the headlamps in the open position and my readings dropped so I have to replace my shaft seal. Thanks. I do have a question about the vacuum reading I get coming right from the intake. I was told I should read between 18-20HG but my car gets a 12-13HG is this a bad thing because that is substantially lower? The previous owner changed the camshaft could this be the reason for the low readings.

 

[duke94]

An agressive cam will lower vacuum levels. As long as you have enough to work the lights and power brake, you're good to go.

Gary

 

[73shark]

Retarded timing will also cause lower vacuum.

 

[Jimmy C]

The website I posted was supposed to be 1975 Corvette Convertible and somehow came out "corvette 1975", something I've never heard of. The "101" site is a good one f/ the vacuum fixes.

 

[82ColEd]

The website I posted was supposed to be 1975 Corvette Convertible and somehow came out "corvette 1975", something I've never heard of. The "101" site is a good one f/ the vacuum fixes.

The CAC changes the URL's title to the Websites title if you have the checkmark in the spot for it ("Automatically retrieve titles from external links "). It still goes to the URL you posted, either way.


-Stefan

 

[Jimmy C]

82coled, Thanks f/ the info, seeing it really messed me up twice as I'm thinking that the site I gave out was of no help what so ever, and/or possibly not even a site. Just tested it. Thanks not only f/ the info, but f/ such a timely reply.

 

[lheindrich]

Gary I finally was able to pull out my left actuator and take a look at that leaky seal and it looks just fine. The rubber is not cracked, I recently purchased the car and the previous owner said he rebuilt the actuators with a rebuild kit. The funny thing is I checked my vacuum levels coming from my green hose on the right headlight when in the headlamp in the open position and I get a reading of 10HG but that headlight functions just fine even though that reading is below my baseline of 12-13HG. On the left I will get a reading of only 8HG. I assume the previous oner just did a poor job putting the shaft seals on. I guess I will wait for my shaft sal kit put everything back together and hope for the best. Thanks, Lloyd.

 

[Jimmy C]

Gary I finally was able to pull out my left actuator and take a look at that leaky seal and it looks just fine. The rubber is not cracked, I recently purchased the car and the previous owner said he rebuilt the actuators with a rebuild kit. The funny thing is I checked my vacuum levels coming from my green hose on the right headlight when in the headlamp in the open position and I get a reading of 10HG but that headlight functions just fine even though that reading is below my baseline of 12-13HG. On the left I will get a reading of only 8HG. I assume the previous oner just did a poor job putting the shaft seals on. I guess I will wait for my shaft sal kit put everything back together and hope for the best. Thanks, Lloyd.

On the site I posted, corvette 101, they state that if the headlights don't open properly, the problem is the sealing gromet, and if they won't close that it's the actuator. The test is/can be done w/ an inexpensive hand-held vacuum pump. I fixed mine using the site info and my problem being the lights-one not opening all the way and the other very slowly, it was the sealing gromet leaking. I almost spent my money on actuators when I didn't need to.