What is the best way to charge the vacuum system to lift wiper door and headlights without the engine running?

 

You can use another engine or use a vacuum pump like the type used for evacuating A/C systems.

 

Thanks

 

I just plug my mityvac into the hose on the front of my wiper door actuator and pump the door open.

If you own a C3 you will own a mityvac sooner or later, it's just part of the package, so the sooner you add one to your toolbox the further ahead of the curve you will be.

 

You can also buy the cheap brake bleeder kit from HF. Pump works good for vacuum system testing!

 

Hi MY70,
The Owner's Manual gives a method for opening the headlights and wiper door without the engine running, if you're goal is just to open/close them, using your hands for the lights and a screw driver for the wiper door.
If, however, you're working on the vacuum system then the pump or mity-vac are the way to go.
Using another car works too but depending how close it is to the car you're working on often the noise from that engine makes it difficult to HEAR, (hissing) ,what your vacuum system is doing.
Regards,
Alan

 

Be careful if you intend to use a refrigeration vacuum pump. These are designed to pull close to an absolute vacuum and will probably colaspse lines and damage diaphrams.

A typical engine will maybe produce about 30 inches of water gauge (vacuum), but a proper vac' pump will be close to 29.9 inches of mercury or 408 inches of water.

Now that sucks!

 

I just went through and completely diagnosed a headlight vac system on a 76'.
It was not difficult at all to do.....and found the issue after about 30 minutes.
This would not have been possible without my MightyVac......
I checked that the reservoir tank was not leaking and then went after the vacuum relays.

Have not done the wiper door yet on my 72' but it will happen....basically the same deal.

Jebby

 

Jebbysan...

FINALLY!!! Someone who took the time to learn about the vacuum system and how to [simply] diagnose and fix it. You would be amazed at how many folks just strip off the vacuum stuff and go to all kinds of cost and trouble to re-engineer it into an electrical operating system.

Your post is testiment to how easy the original system can be tested and fixed for relatively little money [compared to a complete change-over], and how well it works when fixed.

Thanks for your feedback.

 

Well...after re-plumbing 20 feet of Vacuum line as most of it was cracked or missing...I learned this:

1) Use Vacuum pump to check if Res. tank leaks....the 76' is easy as it is up front.
2) When car is running you need vacuum to the two relays up front when the lights are OFF....and the vacuum needs to cut when the light switch is pulled and/or the override under the column is.
3) If the above checks out...use the MightyVac to check the relays across the three vaccum ports....the center port is the main vacuum supply....plug the other two with caps and attempt to draw vacuum....if it will not, replace! BOTH!
4) Finally..use a long length of hose from the tank and jump the canisters that open the lights.....the bottom opens and the top retracts.....check for operation....if no open....Replace!

That's it!
I sat and stared at a vacuum diagram for these right in front of the car.....performed these checks in 30 minutes and ordered two relays on the laptop sitting next to me. Done!

I had never stared at this system before.....my Dad would not even mess with it in the 80's when I was a kid. BUT.....if you know how it works...it is easy!
Staring at the Wiper system on my 72' with a diagram in my hand says that it almost EXACTLY the same....with the exception of the wiper park switch.

It is a intimidating system to stare at....but once you have it in your head...it is a cake walk.

Jebby

 

Thank you all for your reply, I bought my car in 1970 and drove it 25 years before putting it away for 20. Living on the lower Chesapeake Bay I got into boating and parked the car. Now that I have sold the boat getting my car back on the road is on my bucket list. I will get it back in June of 2016 and will post some pictures. Thanks again for your input.

 

GLAD to also see that someone TOOK the time to just look at this ...only to find it is NOT that big of a deal to understand how the system works.

A faster method that can either use the engine vacuum or a vacuum pump. Takes less than 5 minutes. I literally do this a lot when customers call in with vacuum issues.

Engine running or vacuum pump operation...use either a stethoscope or a small rubber vacuum hose and put it up to your ear and take the other end and put it at the bottom square section of the actuator relay. If you hear hissing...the actuator relay is SHOT.

IF you hear nothing...that does not meant that the actuator relay is still good. Now you need to check to make sure the diaphragm of the relay is moving the valving to direct the vacuum when the small hose that is attached to the relay has vacuum on it and when it does not. This plunger moves....thus you will feel a switching of vacuum from the top large port to the bottom large port. This switching is done by the headlight switch and the override switch under the column.

Then with the top and bottom large vacuum hoses disconnected from the actuator relays. Raise the headlight door manually half way and hold it and then with your thumb...cap off the hose end that goes to the rear portion of the actuator pod and press down lightly on the headlight door. If you feel resistance..and then quickly release your thumb ..you can tell the actuator was holding air as designed. THAT step lets you know the main diaphragm inside the actuator pod is good.

THEN...switch to the other hose and do the same thing....IF your feel resistance and then release your thumb...you know the replaceable rubber seals are good. IF you can raise and lower the headlight door...THEN you know your pod seal is shot.

ALSO...the one-way check valve by your intake for the cars vacuum system needs to be just that...a one-way check valve. And the white filter should be checked and replaced also.

AS for checking a vacuum storage tank...regardless of the design. I use the vacuum pump I and and see if it holds vacuum....or if you don't have one....you will know you cars vacuum system is all good when you let the engine run for a while so vacuum can be stored..and then shut of the engine...let it sit for a moment or two and then pull your headlight switch and the headlight doors should go up....or if you have them up...and shut off the engine and wait...they should have enough vacuum stored to make them go down. BUT...also keep in mind about the interior vacuum areas also for your heater/AC...because you can have leaks in this area which can effect this test if the leaks are large enough.

DUB