72and86

OK, so my 71 LS5 is close to the complete vacuum system working.
Lights pop up quickly and go down as they should.

Wipers work and park correctly.

However the wiper door opens on startup and does not go down. (i think in the distant pass it would go up then go down after a minute on startup..?)

Anyway it goes up and stays up, it won't go down until the car is shutoff and I have to manually ease it down. (Cabin over-ride is NOT pulled down)

I last year removed the Wiper Door Vacuum Control Solenoid and cleaned it out, it was plugged. The door worked for a short while , then stopped working again.

Theres no vacuum at the door actuator. I have to be close...

Tiger Joe

I had the exact same problem with my 68.


unfortunately I have no idea what i did to fix it!


Seriously though, I was trying to troubleshoot my system and I pulled the lines off the vacuum canister for the door and then bam all of the sudden it started working


one thing I did read is that the wiper door staying open is a safety feature. when the system has low vacuum, the door defaults to open to ensure you can use your wipers. so maybe there is a leak somewhere?

marshal135

Sounds like the small leak became a big one.
You could maintain external vac via a miti vac on the control line,
small black line on top of relay.
Start the car and see if the door closes.
Most likely the relay. (Drivers Side Firewall)
Try it and post your results.
Marshal

Duntov

I have been dealing with same issue. When start the car the door opens, if not already, and doesn't go down. I had a hole in the red hose the goes from the wiper valley to the override switch. It also seems the "new" wiper valley switch also has failed.

In short term, I plugged the white and red hose together in wiper valley with a coupler. After doing this the door opens and closes with the wiper switch. The timing is off and the door will close on the wiper arm.

The valve by the master cylinder on the firewall controls the door. If the top hose has vacuum the door will close, if not it will open. Ensure the hose on front of the actuator also isn't leaking. If not leaking at actuator (front plug must be in place as well) put vacuum to the canister on firewall by the master cylinder. If closes the issue seems to be either the wiper valley, if join together and works, or the hose to inside the car.

Alan 71

Hi 72/86
The wiper door actuator is controlled by the vacuum relay mounted behind the right side wheel well.
There is a small hose that controls the relay's function and 3 large hoses…
one that is the vacuum supply for the relay, often yellow striped,
a large green striped hose that supplies the vacuum to the actuator to open the wiper door,
and a large red hose that supplies the vacuum to the actuator to close the door.
Have you checked the hose routing to the relay and from the relay to the actuator, and the functions of the relay?
Once you get the door opening and closing you can then attend to have it opening in time for the wipers to start and waiting to close until the wipers have parked.
Check the hoses and relay.
Regards,
Alan

Dave J

OK, we know the actuating vacuum is reaching the actuator through the relay (otherwise the door would not open on startup). We can also assume the relay top control chamber is NOT getting vacuum (otherwise the door would stay down on startup). Relay control chamber gets vacuum - the door stays down. Relay chamber does NOT get vacuum, door raises. Simple.

The trick is to find the reason the control chamber is NOT getting vacuum. The most common issue in this situation is the wiper arm safety valve. When original ones get old, they leak and fail. When new Chinese copies are purchased, they fail right out of the box most of the time as Mr Duntov found out.

If your solenoid is passing vacuum through it now, the next component in line is the override switch. These rarely fail! The next component is the wiper arm switch. A simple test will verify it's condition. Bypass the switch by connecting the two lower hoses together that connect to it (red & white if you look at color). You should now have vacuum to the relay on startup.

This is a simple test. Just remove the wiper grill (not the door). If you do indeed need a new wiper arm safety valve, Willcox sells one that is guaranteed to actually work...........

72and86

Right they open by default to let the wipers have access to the windshield

72and86

I will start by checking these hoses at this Relay. Its hard keeping all these components straight.

72and86

Which component is this and where is it located? If you mean the actual wiper switch inside the car in the wiper control console, that works. The wipers swipe and park.

Im consulting a Wilcox diagram found in another post however the parts arenot labeled.

Dave J

The wiper arm safety valve is located beneath the passenger side wiper arm base, mounted to the cowl area.

72and86

HOW do i test it?

Alan 71

Hi,
Test:
With the plunger pushed in (retracted): the unmarked port should hold vacuum, while the red and white ports are open.
With the plunger out (extended): the port marked white should hold vacuum. The unmarked and red ports should be open.
The red port should remain open regardless of the position of the plunger (extended or retracted).
Check that the plunger return spring is functioning properly and consistently.
Ensure that the ribbed seal is intact and seats in the grooves on the plunger and switch's body.
Regards,
Alan

72and86

Alan, so does the wiper arm safety valve come apart?

Alan 71

Hi 72/86,
No it doesn't.
Well, the rubber 'bellows' comes off, but nothing else.
UNLESS you're Dave, and are able to repair it!!!!!!
I know he's reproducing them... I'm not sure if he's repairing originals?
Regards,
Alan

72and86

Lol gotcha. Yeah Im looking at pics of it, it looks like solid plastic.
Now I do have a JB Industries DV-6E 6 CFM Eliminator Economy Vacuum Pump C1. Can I use it instead of running the engine?

I still have a 1969 that none of the vacuum system works so the pump would come in handy.

Alan 71

Hi 72/86,
I don't know if you can use that pump.
It looks like it might be good for running/testing the entire system.
The mity-vac type pump is handy for testing the components' functions because it has a vacuum gauge too.
You can establish a vacuum on a specific component and then watch how long the vacuum is held, and if it leaks, how quickly the vacuum is lost.
Regards,
Alan

Dave J

Here ya go.............Simple as can be

72and86

ahhhhhh.... thanks.

72and86

I removed it from the car. Im guessing this wiper arm safety valve BELLOWS holds vacuum? Well the bellows is broken off the top and bottom so Im guessing its toast? (I ordered another)

Dave J

The bellows has absolutely nothing to do with the operation of the safety valve. The top vacuum port is simply a vent for the closed to weather chamber the bellows creates when in one piece and installed. It was GM's way of making sure weather (rain, snow) didn't get into the top of the valve.

The new valves do not come with the bellows. You really do not need it if your car is never driven in the elements very much. As you can see in my video, not needed.