Originally Posted by mikeyfev1

Thanks, but there's the current question. When the master switch is in a particular position, let's say the lock position, is it continuously supplying vacuum from the reservoir, or is the vacuum isolated in the lock circuit?

This question is important:

• If the master switch provides constant vacuum from the reservoir, then it is critical that each circuit provides vacuum-holding capabilities, both instantaneously and over time.
• If the master switch provides vacuum to the circuit momentarily and then isolates the circuit, the circuit only needs to be good enough to hold vacuum long enough to switch the mechanisms.

What this relates to is the leak-down requirements of the individual elements and the lines. If they lose vacuum but at a slow rate, then they don't need to be replaced.

So this question is critical to the replacement requirements for individual elements. Since the circuit loses all vacuum when it is switched, that loss is acceptable. But what about when the car is just sitting in an unlocked state?

Does the fact that an element may lose all of the vacuum in the circuit in a few hours matter? In a few minutes? In a few seconds?