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I just had another relay go bad last night. That means I will be replacing the 4th relay since owning this Vette. I work with a guy that bought his Vette new in 73 and still has the original relays! :WTF

Are the repo relays all junk? Are there any other options? I've heard some guys only use 1 relay and T the vacuum lines off of that. Is there a downside to doing that? Seems like I've heard of somebody using an electrically actuated vacuum relay. Anybody ever do this?
 

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The early cars had only 1 relay and my 69 still has the original ones.
Are repro parts junk? Some are just that, others are good. It does make rebuilding these cars a challenge at times.
 

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After a very strange wreck wiping out both headlight mechanisms....

not much of anything else....I went to fixed bulbs, and never looked back....

those operating vacuum lights are a royal PIA.....may check with Chris....69myWay.....he does an electric conversion kit using GM flip motors...

firebird??


to me it makes no sense to have those olde tyme round buggy eyed lights on a car so forward looking EVEN TODAY....

:crazy: :laughing: :rolling: :cheers:
 

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4 Th Relay

If You Had Four Go Out, Maybe Its Not The Relay.
 

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:agree: Some vendors still have the GM relays. They are $$ but worth it.
I've had one on back order from ZIP for 3 months. They seem to be harder to get these days. Ended up buying yet another repo. At least this one worked as received.
 

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Discussion Starter #9
:agree: Some vendors still have the GM relays. They are $$ but worth it.
I guess I will have to do some calling around and see what I can locate. Right now I would have more confidence in a relay from a junk yard than another reproduction.
 

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Those relays are rebuildable if you're interested. I rebuilt my originals about 5 years ago.....so far so good. Usually the rubber valve on the stem that directs vacuum is the problem. I think Eddie70 did his also.
 

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Those relays are rebuildable if you're interested. I rebuilt my originals about 5 years ago.....so far so good. Usually the rubber valve on the stem that directs vacuum is the problem. I think Eddie70 did his also.
I replaced one on my previous vette. and it went out. I still have the originals on my current vette...

How did you rebuild them? I think that would be an interesting and useful post!
 

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:agree: I too would like to see that.

LONG tyme ago I redid one of the door flapper dash pots....they were NLA...

since then they are all eliminated....

I weakened a spring in one for my headlight door as it reacted too quickly on engine start...causing the door to pop up and down, a result of my vacuum canister being perplut.....

so to rebuild one take a Dermel cutter to the clamp ring on the vac canister, carefully split it, the thing then pops apart due to spring pressure, you can see the diaphram there easy....I used a rubber glove palm from a 2 bux pair of grocery store rubber gloves....ground out the rivet, used a nut/bolt, and patterned off the old diaphram.....put the thing back to gether with a shot of silocone spray on the large valves....and put the ring back in place....if you do it nice and neat with a bit of my favoirite RTV to secure against leaks, and hold the metal clamp in place, you let it set up overnight, go install it in the morning.....about a 2 hours fix...plus overnight....

:D :cheers:
 

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OK....first, what happens on these things is that the rubber "piston" that moves up and down in the plastic "cylinder" hardens and shrinks over time. This lets it stop sealing and allows vacuum to escape. There's also a rubber diaphram in the can on top, but it's rarely the problem.
I used a modified version of the procedure on this site. http://iotech.no/corvette/index.htm "Technical"...."headlight relay repair". It's good for dis-assembly and assembly, but you need not go to the trouble of filing down what they call the axle and adding washers.
The rubber piston (seal as they call it) has a flare on each end. These "flares" are what make the seal in the plastic cylinder. The end result you're shooting for is to expand these flares so they contact the inner cylinder again.
Each end of this piston has a "cup" in the end of it....so what you need are 2 O-Rings......5/16"OD X 3/16" ID X 1/16" wall thickness. Clean the cups then swab some RTV or 3M black weatherstrip sealant into the cups. Press an O-ring firmy into a cup and hold it till it sets up a little. On the top cup you can (with a little work) actually stretch the O-ring over the piston.....this saves having to remove the piston from the shaft. I did the top cup first. If you do the bottom one first all the stretching will disturb it. One mistake I've seen made is that some folks think these O-rings end up over or "on top" of the piston. They do not.....they go into the cup at each end. You'll see the o-rings just slightly protrubing from the ends of the piston when all is done. You'll also notice the "flares" are now much more pronounced.......just what you're looking for.
I lightly coated the finished piston and inner cylinder with some silicone lube, and put a very light coat of RTV on the top diaphram. I also bench tested the relays before final installation.
Note ....these things aren't going to look like new with the uncrimping and recrimping of the top can. They will look pretty gnarly.....but they work and are for the most part unseen once installed. It's somewhat of a chore, but the cost is about 15 cents.......4 o-rings for 2 relays.

On a side note....I've seen another procedure where the rubber piston is soaked overnight on some stuff called "rubber restorer". Some said it didn't expand enough to seal. Some said it worked for a while then started leaking again. It could be worth a try, but since you have to pull it apart anyway the O-ring fix is more reliable in my opinion.

Hope this helps
 

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I have rebuilt at least a half dozen. In all cases it was the rubber dog bone lip seals that were bad. The dog bone acts as the valve directing vacuum to the appropriate port when it is pulled up or down by the diaphragm. They get dirty and stiff with age and start allowing blow by. To bad that isn't the case with us old guys :rolleyes: You can easily determine if it is bad by blocking the two outer ports and trying to suck air from the middle port.

The dog bone is held in place by a crimp on the end of the rod. It is a little tedious but you can use a hefty needle nose pliers and compress the crimp out. Some additional filing with a small jewelers file may also be required to de-burr. You can then remove the dog bone, be sure not to loose the small washers on each end that retain the dog bone.

Soak the rubber dog bone in some re-conditioner to soften it. I used some of that stuff recommended for tires.

I then went to the hardware store and got two o-rings properly sized to slip in the ends to expand the lip seal. Can't remember the size but take the dog bone with you when you go to the hardware store.

I also picked up two thin washers in addition to the original ones two retain the o-ring as well as the dog bone assembly after re installing.

Re-crimp the rod end and add a small dab of JB Weld for good measure.

My re-built relays have been working great with some in operation for over two years.

Wish I had taken some pics but maybe next time

Bullshark


P.S. Sorry Rip, you beat me to the post, but That's what I'm talking about
 

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Alright now! Great info guys. I am smarter now. Didn't know that they could be rebuilt:cheers:
 

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