jaluhn83
Full Access Member
I mentioned deleting the mechanical vacuum pump - this is what I replaced it with:
This is an electric vacuum pump setup off a late 80's Volvo. In stock form vacuum is used for 3 things on these trucks - HVAC, brake boost and cruise control. The brake boost is the most critical and needs a large volume so it limits what you can do to replace the stock pump. But go to hydroboost and that restriction goes away. I'm running an all electric cruise system off a 92-94 truck on my rig, so all I need it for is HVAC.
This pump setup is a self regulating pump - the box on the end has a controller that cycles on at ~22 inhg and off at ~25. This makes it easy - connect and go. I am not sure on the rated duty cycle but I'd think it's pretty good. These pumps were used on mid 80's Volvo 760 turbos with automatic climate control to boost the vacuum to the HVAC system under boost as the limate control system operated using a metered vacuum control that requires a constant vacuum to function properly. The Volvo part number is 1329604, but it's $350 from them. I've found a few in junkyards - looks for 740/760/780 cars and look on the driver's front fender area.
Or look around:
http://www.ebay.com/itm/Volvo-740-760-Vacuum-Pump-out-of-1984-Turbo-2-3-/400563416712?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d4370ae88&vxp=mtr
The pump appears to be an OE AC Delco unit and I suspect other late 80's 'luxury' cars would have used the same or similar but don't know of any for sure.
It does work well though. Make sure and get the mounting frame and the rubber mounts - with my setup you can barely hear it running. I left the stock small circular resiqviour attached and it takes about 15 seconds to pump down and kick off, then has enough vacuum to cycle through all the HVAC settings without coming back on. Do make sure the system is tight though, it's sensitive to small leaks.
This unit is setup with 3 wires - power, switched hot & ground. Power goes to +12 and ground is obvious, then when you put power to the switched lead it'll come on. I tied the switched lead to the fan power wire (brownish red wire) so anytime the fan motor is running the vacuum pump is online. The fan speed control works on the ground side so this will work for all fan speeds.
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This is an electric vacuum pump setup off a late 80's Volvo. In stock form vacuum is used for 3 things on these trucks - HVAC, brake boost and cruise control. The brake boost is the most critical and needs a large volume so it limits what you can do to replace the stock pump. But go to hydroboost and that restriction goes away. I'm running an all electric cruise system off a 92-94 truck on my rig, so all I need it for is HVAC.
This pump setup is a self regulating pump - the box on the end has a controller that cycles on at ~22 inhg and off at ~25. This makes it easy - connect and go. I am not sure on the rated duty cycle but I'd think it's pretty good. These pumps were used on mid 80's Volvo 760 turbos with automatic climate control to boost the vacuum to the HVAC system under boost as the limate control system operated using a metered vacuum control that requires a constant vacuum to function properly. The Volvo part number is 1329604, but it's $350 from them. I've found a few in junkyards - looks for 740/760/780 cars and look on the driver's front fender area.
Or look around:
http://www.ebay.com/itm/Volvo-740-760-Vacuum-Pump-out-of-1984-Turbo-2-3-/400563416712?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d4370ae88&vxp=mtr
The pump appears to be an OE AC Delco unit and I suspect other late 80's 'luxury' cars would have used the same or similar but don't know of any for sure.
It does work well though. Make sure and get the mounting frame and the rubber mounts - with my setup you can barely hear it running. I left the stock small circular resiqviour attached and it takes about 15 seconds to pump down and kick off, then has enough vacuum to cycle through all the HVAC settings without coming back on. Do make sure the system is tight though, it's sensitive to small leaks.
This unit is setup with 3 wires - power, switched hot & ground. Power goes to +12 and ground is obvious, then when you put power to the switched lead it'll come on. I tied the switched lead to the fan power wire (brownish red wire) so anytime the fan motor is running the vacuum pump is online. The fan speed control works on the ground side so this will work for all fan speeds.
