Source for secondary vacuum actuators?

[Matt B]

My Z has a vacuum leak somewhere down the secondaries tubing. Even with the throttle body hose plugged I can't draw considerable vacuum. I checked with an endoscopic camera but no visible damage.
So I'm up for my first plenum pull.

As most things take ages to eventually arrive at my shop (Marc's memcal took 5 weeks) I'd prefer to stock a pair of secondary actuators. Just to be save... All the rest can be fixed with stuff I have on hand.

But I can't find any. Where could I get them?

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[HAWAIIZR-1]

Using Cliff?s procedure post #121, my leak was confirmed to be check valve, but I have not changed it yet.

https://www.corvetteforum.com/forums...-500-hp-7.html

Did you try Jerry?s Gaskets? You?ll easily be able to test the actuators pulling the plenum. Not sure where else to source new other than EBay when they pop up. Sorry, I have some extra NOS, but don?t have access to them now. Be sure to check new ones because of the diaphragm incorrectly built from factory. I had to refund and replace two when I found them new.

Some people will tell you to remove the secondaries, but that is not an option for me. I also like them to work as designed.



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[G8nightman]

I have a set for sale if you need them send me a pm.


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[Matt B]

Thanks, dropped you a message.

I checked Jerry's but he ran out of them. Deleting the Secondaries is no option for me either. This is the damn coolest feature a ZR has. I even asked Mark to program my chip in that way so "full power off" remains standard. So cool to look into the stunned face of the right passenger after a short acceleration and then say "Oh, wait, we're still in half power mode!"

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[Young1]

Matt. It appears you are doing a careful diagnosis. Your actuators will not work if the vacuum solenoid for them has failed. It is Standard part number VS124. Common source of vacuum leak also. I have replaced 4 of them in the last five years in 3 different cars. The mounting brackets have to be cut off and screwed together because the original part in NLA. Be sure to do the test for actuator operation per Marcs website. His video IMO is worth it to perform your first plenum pull. Best of luck in keeping your beast alive.

[Matt B]

Thanks, the selenoid is a good point - I will put spare parts on my list. Is it that one? https://www.rockauto.com/de/parts/st...d+/+motor,4380

Marcs video unfortunately doesn't make sense for me as it's in a video standard that won't work here. And why the heck did I forget to ask him when I ordered my memcal???? Must be the age...

Does anyone know if there's a version in a standard video format like an .mp4 available? Probably it's best to drop Marc a message.

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[A26B]

Originally Posted by Matt B

Thanks, dropped you a message.

I checked Jerry's but he ran out of them. .........................

Still showing inventory, if you are not be able to get them elsewhere.

[Young1]

Yes confirmed that is the part at rock auto.

[Matt B]

Just pulled my plenum today (Marc's DVD is SO cool!) and did a leak down test on the entire secondary vacuum system. Indeed the actuator seems to be leaking. Actuators work perfectly fine and hold vacuum for many minutes. Also all other hoses and connectors are super tight.
Only the check valve was a bit leaky, but when I blew it with some compressed air a tiny piece of debris fell out and now it work perfectly well, too.

So, time to order a new selenoid and hope this will resolve the short hesitation when Secondaries kick in. Thanks for the advice!

[Matt B]

Thanks for the recommendation for replacement. I pulled the stock selenoid, opened and cleaned it. Seems tight now but considering the effort to replace it I'll better install the new one.

Mountain brackets in theory could be simply swapped if one wants, I preferred to re-worked the new one using some sheet aluminum and pop rivets. So the OEM goes to the shelf.
Hope it'll fit as the OEM one stands a bit higher, though.
Ah, and the socket has to be modified slightly (left is the new one, the little tab separating the contacts has to be cut out).

The unit itself seems a 1:1 replacement with identical body and shape. 20210720_224135.jpg20210721_074339.jpg

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