vacuum switch question

[mikevochis]

I'm currently having some mild engine work done on a 1978 L82. My mechanic thinks there should be a "vacuum switch"(maybe incorrect wording) in the thermostat housing. My local chevy dealer can only find the part for a 1979 & newer. I think my mechanic might be describing the part wrong, or maybe there shouldn't even be one. Any help...part number or correct name, would be greatly appreciated.

 

[Dave L.]

ported vacum switch

mikevochis- I have an original 78 only catalog at work.I'll verify that info and post it here when I get to work in the morning.I think that should have one.It's called a ported vacum switch.

Dave

 

[rpounds]

Take a look at this:

http://www.docrebuild.com/dr-r-web/3460110.HTML

And this:

http://www.docrebuild.com/dr-r-web/3750367.HTML

www.docrebuild.com shows two Thermal Vacuum Switches (TVS), the same as is found on my '75. However and L-82 may be different.

Hope this helps.

Ron

 

[Big Fish]

If it's the same as a 75 the thermostatic switch in the thermostat housing controls the diaphragm for the heat riser valve located on the right side exhaust manifold outlet. That is all the switch did. If the heat riser is no longer there the switch could be eliminated. I got rid of mine by using a bi-metal operated heat riser valve.

 

[Dave L.]

ported vacum switch

current GM# 355963.Still available from GM Parts. Current list price 14.32 - wholesale 10.03.

 

[mikevochis]

You guys are the best!!!! Thank you