The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - can anyone tell me what these parts are and what they do?

tucsonjwt · 04-16-2011, 07:41 PM

I don't know for sure, except #3 is your cruise control servo.
#1 is a PVS (Ported or thermal vacuum switch) in the middle with two nipples which should have vacuum lines attached (I think). The other two are obviously some sort of thermal switches also, but i have not seen them before.
#2 looks like it might be an older version of a cruise control servo, but I thought those were mounted on the driver's side fender.
I am sure someone with more knowledge than I will post here.

04-16-2011, 07:41 PM	#3
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,198	Re: can anyone tell me what these parts are and what they do? I don't know for sure, except #3 is your cruise control servo. #1 is a PVS (Ported or thermal vacuum switch) in the middle with two nipples which should have vacuum lines attached (I think). The other two are obviously some sort of thermal switches also, but i have not seen them before. #2 looks like it might be an older version of a cruise control servo, but I thought those were mounted on the driver's side fender. I am sure someone with more knowledge than I will post here. Last edited by tucsonjwt; 04-16-2011 at 07:43 PM.