That starts to get tricky... Could be lots of things in the dash... You could use a Vacuum testing tool to pull vacum on different lines to test for leaks... You may not know whether its a faulty actuator or lines but you can at lease further refine where the source of the problem is.

I don't know what the other guys think... But once it's in the dash, unless you can see it from below, it makes little difference.

 

Speaking of rubber air supply fittings...If your auto parts store doesnt have them try Home Depot, their sprinkler sysrems or drip systems have a large variety of plastic parts that may work aswel.

 

I know this is for the 24v. I am having the same issue on my 12v. I have looked through the 12v section and I do not see a post regarding this engine. I might be overlooking the plethora of information. Do any of yall have an idea as to where this would be located? Same exact issue that I am having.