Going to Terre Haute next month, and it would be nice to cruise with the windows up! AC lines were disconnected when I pulled the motor, so I am starting from scratch. I'd rather buy the tools and refrigerant than pay a shop. Any advice or links are welcome. Thank you, C

 

I would also like to know I have a compressor to change out and would like to get this done...without a shops help. It's just two lines I need to disconnect and pop the new compressor in. Just worried if I do not have it vaced if it will matter......

 

you should evacuate the system with a vacuum pump. pull it to at least 500 microns. then charge it up.

 

Thanks Ken! So should I get a mightyvac? And where do I pump from?

 

Agreed... I have one of these not sure if it will be sufficient
Buy Mityvac Fluid Evacuator MIT7400 at Advance Auto Parts

where to pump from is also my question.

 

you will need a vacuum pump, and a manifold set. draw a vacuum on the low pressure side for at least 1/2 hour, shut the valve off, and look to see if you loose any vacuum. if the gauge stays at 29-30 inches vacuum for at least 1 hour, then you are good to charge. do not overcharge the system. the proper amount will be on a tag on the rad support.
only charge through the low side. if you try charging through the high side, there is a very good possibility the can will blow up in your face.

 

Good info, any ideas where to get a vacuum pump? Will a mightyvac work?

 

no. you need a real vacuum pump made for air conditioning systems, something like this:
Single Stage 3CFM 1/4HP Rotary Vane Vacuum Pump HVAC Air AC A/C R410a R134a etc. | eBay
and a manifold set like this one:
http://www.ebay.com/itm/HVAC-A-C-Ref...6772ce&vxp=mtr

 

Check out how to evacuate an automotive AC system with an HVAC vacuum pump
Then take a look at How to Charge an automotive AC system by the same guy. these videos dont talk much about safety so be aware that the High side pressures are very high and could hurt you in several ways. the high side of an auto ac system could pop one of those auto store cans of 134a. i would hope they have some kind of check valve like the 30# jugs but who knows. the video doesnt mention Vacuum pump oil either so be sure to read the instructions for the pump.

 

If the system was left open for a coue days are more then I'd suggest changing the dryer and orifice tube.

 

your looking at 4grand in tools to do it properly, unless you borrow them.

New dryer and orifice tube for sure.

 

Technically, he's supposed to evacuate first, then pull a vacuum. Though its a semi clean system he can just use a vacuum pump.

Being a re-done system, I would let the vacuum set for 2+ hours.

 

Pull a Vacuum=Evacuation

A system that has been open for some length of time should be swept with nitrogen. then evacuated again.

 

Harbor Freight has a decent price on vacuum pump as well as a R134 manifold set. Also do not forget to add the oil charge not just freon only or you will ruin the compressor. Good luck.

 

Uhhh. Vacuum pump and evacuator are 2 different things. Perhaps I'm calling it by a different name.

You dont pump gasses with a vacuum pump.


and yes, you should clean it with nitrogen to help break loose particles in the system.