1965 Coupe Air conditioning Hot Water Vacuum control swtich info and Questions

[William H.]

Re: 1965 Coupe Air conditioning Hot Water Vacuum control swtich info and Questions

Hello Garry,
So are you saying the the long seal I took out of my two valves goes where you put the white heat shrink?
Or that it goes about where you show it in your picture?
IF you put it where you show it in your picture the valve works great, except backwards and passes vacume when the plunger is depresse and is blocked when its released you can tell this because in the non depressed position the .092 necked down area is right between the two ports. No vacuum can pass no matter how long the seal is. I think that people that think it works with one or two o rings in that .092 area are confused about when it does pass vacuum and when it doesn't. This would make thier AC work poorly and their heater not at all, I would think, but several people mentioned they just unhook the vacuum at the water valve in the summer and hook it up in the winter so maybe the orings in the wrong place is the reason why. Ive got my valves to work whith the two pieces of seal on each side of the .092 area as shown in my pictures but I would still like to know how it works if you put it in the stepped down .092 area???
I've ordered a new one and I'm going to take it to work and X ray it and see what's inside. Not sure if I'll be able to see the rubber but maybe I will . I would just take it apart but I bent the shaft on mine taking them apart and so now they don't work in all positions. As you rotate the shaft 360 degrees the valve will get stuck depressed in some positions.
Thanks for your help
Bill

[Garry M.]

Re: 1965 Coupe Air conditioning Hot Water Vacuum control swtich info and Questions

Bill,

Attached are two additional pictures I have created for my article. It shows how I believe the valve is intended to work, and the way it worked for the fix I implemented. In my original picture, I am showing the location of the seal as being where it is positioned, essentially between the two o-rings. The white heat-shrink tubing is an attempt to hold the on o-ring in position (i.e., won't slide down the shaft towards the plunger button). The clear shrink tubing in the center attempts to replicate the tapered down area of the original seal, while the two o-rings create the ends of the original seal. Keeping it all together is the bigger challenge, and have it be free enough to move/release yet tight enough to seal. It would work a few times (I used grease) but then the plunger would get stuck (I even tried a stiffer spring). Just couldn't find the right sized o-rings (I created mine by shaving them flat).

As you can see from the pictures (which I tried to make them look like actual based on measured dimensions), there is very little room for variance in that you get no vacumm to the heater switch in open mode or you don't get it bleed off in closed mode. BTW - the little black dot is the bleed off hole.

I can relate to the bending of the shaft... the more I played with it the worse it got. I would hope that new model would simply have two groves cut into the shaft and use o-rings - but that is probably not the case since they still leak (or I got a bad one).

Cheers!
Garry

Vacuum Switch Closed.jpgVacuum Switch Open.jpg

[William H.]

Re: 1965 Coupe Air conditioning Hot Water Vacuum control swtich info and Questions

OK I see now. I didnt see that the old seals might be smaller in the middle. I guess they just got that way because the shaft is smaller in that area . My originals are too big ID they just slide up and down the shaft and too little OD they don't seal but I guess they have gotten hard and also shrunk over time. Ill let you knoe when I x ray the new one how it is made.
By the way when I got mine to work I used two pieces of vacuum hose and sanded down the OD in the drill press then I super glued them to the shaft.
Thanks for all the info and hurry up with that article I think it would be a good reference.
Thanks again,
Bill