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This valve is mounted on the rear of the tach housing. Has a electrical connector, and 2 vacuum ports.(from overide to headlight switch) Now that I overexplained this, here's the question. On the plastic port end there's a small hole in the end. Is this a bleed hole or just time for a new valve?
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Re: 70 tach valve
It's broken. Good luck finding a replacement! -
Re: 70 tach valve
It's broken. Good luck finding a replacement!Comment
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Re: 70 tach valve
Dennis-----
I'm not sure that the valve is bad. There's supposed to be a foam "filter" over the end, but it's not critical. Does the wiper door system work alright when turned on at the wiper switch with this valve installed? If it does, the valve must be alright.
The valve (actually a vacuum switch) was GM #5638276. It's GM-discontinued and has been for a long while. It's not currently reproduced and it's hard to find. There's an NOS example on eBay right now (eBay #7948277325). It's only at $41 right now but I'll bet it's a lot more "when the gavel comes down".In Appreciation of John HinckleyComment
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Re: 70 tach valve
Dennis-----
I'm not sure that the valve is bad. There's supposed to be a foam "filter" over the end, but it's not critical. Does the wiper door system work alright when turned on at the wiper switch with this valve installed? If it does, the valve must be alright.
The valve (actually a vacuum switch) was GM #5638276. It's GM-discontinued and has been for a long while. It's not currently reproduced and it's hard to find. There's an NOS example on eBay right now (eBay #7948277325). It's only at $41 right now but I'll bet it's a lot more "when the gavel comes down".In Appreciation of John HinckleyComment
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Re: 70 tach valve
Joe
It functions fine. Is the hole OK or should I epoxy over itComment
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Re: 70 tach valve
Joe
It functions fine. Is the hole OK or should I epoxy over itComment
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Re: 70 tach valve
Dennis-----
No, I would absolutely not epoxy over it. I believe that the hole is intentional and necessary.In Appreciation of John HinckleyComment
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Re: 70 tach valve
Dennis-----
No, I would absolutely not epoxy over it. I believe that the hole is intentional and necessary.In Appreciation of John HinckleyComment
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Joe's 100% correct!
The hole is what allows vac to vent and raise the wiper door when you turn on the WSW switch! If you plug it all (*&& is going to break loose in terms of consistent operation....
As Joe and others said, the original relay valves had a rectangular 'chunk' of foam rubber covering the vac vent port that did a 'modest' job of filtering air. This foam isn't really necessary as you have an in-line vac filter on the system as a whole between the intake manifold and the check valve. The vent tube on the wiper door safety switch simply ran through a cowl grommet and sat 'open' in the engine compartment (no discrete filter on it)....
But, if you feel better with a filter on your WSW electro-vac relay behind the dash, go cut a 1 x 1 inch square, roughly 3/8-inch thick of VERY porous foam rubber, square the end of the vac vent tube, apply a circular bead of cyanoacrylate (super glue) and stick the foam in place....Comment
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Joe's 100% correct!
The hole is what allows vac to vent and raise the wiper door when you turn on the WSW switch! If you plug it all (*&& is going to break loose in terms of consistent operation....
As Joe and others said, the original relay valves had a rectangular 'chunk' of foam rubber covering the vac vent port that did a 'modest' job of filtering air. This foam isn't really necessary as you have an in-line vac filter on the system as a whole between the intake manifold and the check valve. The vent tube on the wiper door safety switch simply ran through a cowl grommet and sat 'open' in the engine compartment (no discrete filter on it)....
But, if you feel better with a filter on your WSW electro-vac relay behind the dash, go cut a 1 x 1 inch square, roughly 3/8-inch thick of VERY porous foam rubber, square the end of the vac vent tube, apply a circular bead of cyanoacrylate (super glue) and stick the foam in place....Comment
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