View single post by Frank Schwartz
 Posted: 08-15-2011 09:33 pm
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Frank Schwartz


Joined: 02-18-2011
Posts: 279
Well, in all of the dozen or so JH's I have encountered or worked on, the metal vacuum operated valve which is attached to the valve cover was rusted open and totally ruined.  I found a generic, mostly plastic, valve at NAPA that worked very well. The vcuum comes through the manifold t near the brake booster, goes inside the car to a tiny valve mounted in the footwell on the side next to the gas pedal on the heater box. Looks like a square click on click off ball point pen. When the lever is thrown all the way over, part of the mechanism pushes down on the tiny valve end and opens the vacuum or closes it off...I cannot remember.  I suspect the big valve in the engine compartment is closed on vacuum and opened without...nonetheless, that is the wayit works. You will have to be a contortionist to get up in there in the drivers footwell to see it, but if either of the small rubber hoses is off or broken, the valve cannot work.  I suggest removing the valve mounted on the engine and inspecting it. If it is rusted badly or will not actuate with and without a bit of vacuum, it should be replaced.   Some use an aftermarket cable operated off/on weater valve, with the handle up undeer the dash mounted on the left side wall of the car for access...but in the later cars, I suspect the owner has overlooked this vacuum switch up inside that I mentioned.  In case the hoses to this tiny switch are bad, you will have a vacuum leak that is continuous in your system...that is not desireable. Check with our webmaster, Greg, to see if he has replacement water valves..if not, try Delta.  I have no financial affilliation with either...both great helpful people.