For those older than me, do any of you remember vacuum trunk system issues like the thing opening on its own, either during driving or while parked?

Making several assumptions:
1. Engine vacuum, while running, is a positive value (as in, always below ambient) or zero, at worst.
2. The reservoir should have a functioning check valve.
3. The button is a nominally complete block of the vacuum line.
4. The hoses should not leak appreciably.

I am wondering what the chances are of vacuum leaking by the button at a rate that could get the trunk actuator to work. I don't think it is possible in enough amount to get it to go.

 

Maybe its the latch? Disconect the vac portion drive arnd and see if it still happens.

 

It's a hypothetical. Car does not have the system on it now.

 

The only possible failure mode that can cause the vacuum actuator to operate is a leak at the button. Any other failure causes the vacuum system to bleed to atmospheric, which prevents the actuator from operating. If the button leaks slowly, there will eventually be vacuum in the line between the button and the actuator, causing it to operate.

 

My thoughts were similar. Those buttons seem pretty reliable based on the loose ones I have. I need to setup my mityvac hand pump and the system to see how long a button hit it takes to actuate it. I don't think the button vents the trunk side to atmosphere; I wonder what does. Theoretically, you should be able to push the button, vacuum pulls the actuator in, opens the trunk....then you release the button and what happens? Presumably the spring returns the actuator, but there should be a vent to relieve the vacuum either at the button when released, or the actuator as it is returning to extended. I will find out.

 

Correct.

 

I’ve found the vacuum trunk release very robust through the years. They were well made by a company called Trico who seems to have sold them to GM, Ford and Chrysler in the old days.

My big cars have tons of vacuum accessories — trunk lock, heater, a/c & vacuum door locks. It’s fun to see them work. They leak a little more than I’d like, but I chalk it up to 50 year old diaphragms and rubber lines which may not have been perfect when new.

The vacuum functions work great when the engine is running. I just always find myself wanting to lock doors or pop the trunk with the engine off. Then the rate of leak down seems to make them not work too well. I’ve stashed vacuum tanks up under my passenger fenders to keep the systems working just a little longer after shutdown. I pulled ‘em off Caddies somewhere in the 80’s and they work great.

Can the vacuum trunk lock switches be rebuilt or reconditioned? I’ve never really looked