sheldonbaker

hey just got my wipe door working goes up down just like it should but after you turn the car off and the wipes off they door is down but its like and u can here the vac ,,, just about the time all the air is out the wiper door pops back up ,,

Easy Mike

You have a vacuum leak and it might be at the check valve.

Alan 71

Hi sb,
Since the problem occurs with the engine not running, you might well be able to locate the leak by listening carefully while looking under the hood.
It might be the check valve as Mike suggests, (but that's often silent), but it could also be the wiper door relay, or even the door actuator.
Do you have any 'sleuth' in you?
Good Luck!
Regards,
Alan

...Roger...

Pinch off the hose between the check valve and the manifold,if your problem goes away replace the check valve.

BBCorv70

You may want to check out your vacuum relays. I just spent a lot of time working on my wiper door too, also a 70, thought the linkage was binding. Turns out it was binding only a little bit, bigger problem was several vacuum leaks. All three vacuum relays were leaking. Biggest offender was the right front headlight relay.

For the door to pop up, vacuum is being applied to the backside of the actuator or the vacuum bleedoff differs, frontside losing vacuum before the rear though rear shouldn't have any unless something is leaking in the relay. Possible vacuum to the small hose going to the relay is lost before vacuum is lost to the large hoses, this would cause the door to open.

I found my leaks by connecting a vacuum gauge and pinching hoses, watch for reaction. When I pinched and released the hose for the right front headlight I got a big reaction. Others bit less so..

A hand held vacuum pump with a gauge is quite handy when testing the components.

mrvette

I found the Vac storage tank on my '72 was split/defective it was mounted up over the evap gas canister under the left fender....kinda impossible to get to....had 3 vac lines going to it....

caused all kinds of weird problems with all that vac stuff, I just eliminated it....

BBCorv70

Pretty easy to test. One line comes from the intake manifold, one goes to one of the headlight vacuum relays, the other goes to the other vacuum relay and has a T to bring vacuum to the wiper door vacuum relay and heater controls. Just pinch off the two hoses which are not the one coming from the intake. Either use a hand held pump with gauge or put a vacuum guage in a T between the engine and the tank. Pinch the hose going to the tank and note any reaction on the guage.

Replacing the tank looks like it would be a bear.

sheldonbaker

ok guys its only when the car is truned off ,, that the door comes open ,,, and as soon as i start the car the door goes closes does that help with out the wipers on ,, the wipers are off

...Roger...

What did this test show ?

72 bucket of parts

I am a little confused. if you turn the car off the vacume goes away and the door should stay down. needs vacume to move either way. If the wiper lifts off the vacume park swith before the vacume bleeds away that may cause it,,,, wouldn't it?

Kelley

...Roger...

If the wiper lifts that valve might do it,but thats not really how that valve is set up,its not really set up to dump vacuum from the lower port ,the middle port is the one that gets dumped into the top port. The lower port vacuum gets dumped by the solenoid or pulldown through the middle port.
That valve could be his problem simple because it leaks.

sheldonbaker

what valve its got a new wipe switch that the wipe lays on with the rubber around it i do here air come out of that around the rubber the rubber is just a dust cover for that right it has new wiper actuators and head light ones to and new actuator relay valves to ,,,