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Vacuum relays

 
Old 02-19-2019, 12:48 PM
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croaker
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Default Vacuum relays

As per videos and information Iíve watched and read the relays should hold vacuum , pump on middle port bottom plugged they pump up but wonít hold vacuum when not pumping. Three new ones none hold.
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Old 02-19-2019, 01:11 PM
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Repops are great, huh?
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Old 02-19-2019, 01:16 PM
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Junk. They even told me they checked them.
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Old 02-19-2019, 01:19 PM
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Corvette America pieces
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Old 02-19-2019, 01:36 PM
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There is a guy here that repairs originals.
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Old 02-19-2019, 02:54 PM
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Originally Posted by croaker View Post
As per videos and information Iíve watched and read the relays should hold vacuum , pump on middle port bottom plugged they pump up but wonít hold vacuum when not pumping. Three new ones none hold.
I got my mine from Corvette Central and can vouch that they worked. My 69 headlights and wiper door now work as they should.
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Old 02-19-2019, 03:55 PM
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Originally Posted by jpatrick62 View Post
I got my mine from Corvette Central and can vouch that they worked. My 69 headlights and wiper door now work as they should.
$20 sez they all come from the same factory.
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Old 02-19-2019, 06:40 PM
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Originally Posted by Big2Bird View Post
$20 sez they all come from the same factory.
Kinda like lawn tractors? Maybe you are right, but I guess I bought mine on a day when the assembly line guys were paying attention to what they do!
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Old 02-19-2019, 06:47 PM
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Originally Posted by croaker View Post
As per videos and information Iíve watched and read the relays should hold vacuum , pump on middle port bottom plugged they pump up but wonít hold vacuum when not pumping. Three new ones none hold.
https://www.corvetteforum.com/forums...-l-relays.html
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Old 02-19-2019, 09:13 PM
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Thanks for the link. I took the top off one of the originals. I saw a article on trying to revive my old one. Top may not go back on. I thought about sending them off for rebuild. I may still try that. The ones I just bought were Packaged with inspector Pattyís seal of quality control.
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Old 02-19-2019, 09:31 PM
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I took the top off one of the originals.
The top vacuum control chamber is probably the only vacuum part of it that still worked. I have not found many original relays that did not have a good top control chamber. It's the internal piston that looses it's sealing ability over time. The reason is the piston degrades from the junk that gets sucked in from the open port on the bottom that the often missing filter misses. The rubber piston is also eaten away from the most common enemy of rubber and that is ozone.

When I rebuild relays I replace the old piston from the bottom of the relay. I have a machining process that works well for this.

The biggest issue with the import junk relays is the tolerances realized from the molding process of the main body. I have found bore tolerances all over the map. The original GM 50 year old relays are for the most part still tight. When you have such wide differences in bore diameters like the imports show, it's true you may have some good ones, but for how long? Sort of like playing relay roulette.
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Old 02-19-2019, 09:33 PM
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Originally Posted by croaker View Post
Thanks for the link. I took the top off one of the originals. I saw a article on trying to revive my old one. Top may not go back on. I thought about sending them off for rebuild. I may still try that. The ones I just bought were Packaged with inspector Pattyís seal of quality control.
DaveJ. That's the fellow.
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Old 02-19-2019, 11:20 PM
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Originally Posted by Big2Bird View Post
DaveJ. That's the fellow.
Dave is the guy.
I've had nothing but trouble with new relays. When used on earlier models with a wiper door you need the relay to work or actuate before the wiper door starts to open as the default of the relay is the open position. The aftermarket seems to think a big heavy spring in the relay is better for some reason. Wiper door then pops up and retracts on start because the heavy spring makes it impossible to stay closed as it requires more vacuum to actuate the relay than the wiper door actuator. The door then pops up until there is enough vacuum to overcome the spring in the relay then the door goes back down. Only a second but enough to **** you off.

Last edited by CanadaGrant; 02-20-2019 at 12:09 AM.
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Old 02-20-2019, 04:41 AM
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Originally Posted by Dave J View Post
The top vacuum control chamber is probably the only vacuum part of it that still worked. I have not found many original relays that did not have a good top control chamber. It's the internal piston that looses it's sealing ability over time. The reason is the piston degrades from the junk that gets sucked in from the open port on the bottom that the often missing filter misses. The rubber piston is also eaten away from the most common enemy of rubber and that is ozone.

When I rebuild relays I replace the old piston from the bottom of the relay. I have a machining process that works well for this.

The biggest issue with the import junk relays is the tolerances realized from the molding process of the main body. I have found bore tolerances all over the map. The original GM 50 year old relays are for the most part still tight. When you have such wide differences in bore diameters like the imports show, it's true you may have some good ones, but for how long? Sort of like playing relay roulette.
Dave do you sell the rebuilt oem relays? Iíd buy a couple if you do..
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Old 02-20-2019, 08:49 AM
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Originally Posted by ajrothm View Post
Dave do you sell the rebuilt oem relays? Iíd buy a couple if you do..
. Dave can you work with the new ones or just the the originals?
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Old 02-20-2019, 12:25 PM
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I really, really prefer the original GM relays. Several reasons. Internal bore dimension consistency, top vacuum chamber almost always still vacuum tight (not so much on the repops), rebound spring tension correct, and quality of base plastic material. I suppose I could try again, but with the reported issues with the internal rebound spring I don't have much hope. I personally have not had the spring issue, but I don't do much with the new relays anymore to really get into it. There are original GM relays out there on the market that would be good candidates for rebuilds. I've been collecting them for years.
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Old 02-20-2019, 06:40 PM
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I agree with DaveJ somewhat.

YES...the springs that I have pulled out of some of the reproductions are to stout.....which can effect how the headlights or wiper door react when you crank up the car initially. I created a thread on this to show it.

https://www.corvetteforum.com/forums...t-problem.html

I have had very good success from getting the relays from Lone Star Caliper. I have 20 of them on hand and ALL of them work perfectly. When I talked with one of the guys there....he tested them before he shipped them out to make sure they did not leak.

But yet... I did get so many of these relays from other sources PRIOR to me getting them from Lone Star and it was 'hit or miss' if they would work at all..or for how long they would work.

I think there are different sources due to some I had to install when the customer bought them from Mid America Corvette had 1-800- MAD-VETT cast into the plastic.

I also have about 30+ origianls and sometimes I rebuild them so the 'AC SPARK PLUG DIVISION' logo is able to be seen.

IF you buy a repo...and notice the headlight / wiper door wants to pop up and then go back down again.....there is way to stop this that DOES NOT require any serious modification that will ever bee seen.

DUB
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Old 02-21-2019, 08:48 AM
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Dub, will you elaborate on this fix, either on this thread or via PM. Thanks
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Old 02-21-2019, 09:09 AM
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Originally Posted by c69vete View Post
Dub, will you elaborate on this fix, either on this thread or via PM. Thanks
please do!
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Old 02-21-2019, 12:25 PM
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Originally Posted by c69vete View Post
Dub, will you elaborate on this fix, either on this thread or via PM. Thanks
What I finally figured out is in the thread below. Trial and error getting there but the wiper door works perfectly now.

https://www.corvetteforum.com/forums...uum-issue.html

Last edited by CanadaGrant; 02-21-2019 at 12:27 PM.
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