Best way to seal vacuum hose connections

[Gary B.]

Mark,

You can contact Dave thru the Corvette Forum. His user name there is “Dave J”, for Dave Jacobs.

Gary

[Patrick H.]

Mark,

You can contact Dave thru the Corvette Forum. His user name there is “Dave J”, for Dave Jacobs.

Gary

Yes, that's why I included that early on.
I would send you his email, Mark, but the silly PM system here won't open the message you sent in order to respond to it. Edit - fixed that; see your PMs.

Did you try installing the new valve on the car to see if it actually works correctly?
At least one if not both of the common "vacuum troubleshooting guides" is incorrect on how to test this valve.

[Mark E.]

I don't have a CF account.

Patrick- Thanks for the email. A guide wasn't used for testing; I just thought through the logic of the system.

I'll try installing and testing it (easy to do) but since the W port does not purge when the plunger extends, I suspect the wiper door will either not open or open gradually as vacuum leaks down in the system.

[Mark E.]

The DaveJ interlock valve arrived yesterday from Zip (CC's website had problems). This valve failed too. Tests performed:

With plunger depressed (wipers off):
- R port passes vacuum to the W port (PASS). This energizes relay to close wiper door.
- R port holds vacuum with W port plugged (PASS). This tests for leaks in the valve.

With plunger extended (wipers on):
- R port holds vacuum (PASS). This prevents a vacuum leak to the engine.
- W port should purge to B port, releasing vacuum to the relay's control line to open wiper door (FAIL- B port leaks to housing and W port does not pass air).

I'll reach out to Zip to see if they're willing to test another valve. If I had DaveJ's contact info, I'd like to reach out to him as well.

I emailed Dave and he called within 10 minutes. He was gracious enough to correct me about the purpose of the Black port on the valve. It is NOT for purging the control vacuum like I thought; it is for equalizing pressure inside the rubber boot of the valve. The control vacuum is purged by the vacuum solenoid located behind the tach.

This means the valve operates as designed. Corrected test:

With plunger depressed (wipers off):
- R port passes vacuum to the W port. This energizes relay to close wiper door.
- R port holds vacuum with W port plugged. This tests for leaks in the valve.

With plunger extended (wipers on):
- R port holds vacuum. This prevents a vacuum leak to the engine.

Thanks again Dave!