Discharge car freon - MDX Acura Cars & Trucks

Its best to evacuate the a/c but if you are careful you may be able to hook up your freon tank and lightly charge the system if it works cold just let it be and if when it is real hot it feels warm instead of cold you might add just a little more freon but be careful.

Yes and no.
Yes you should, because that helps remove moisture and allows a full charge of freon.
No, you can put enough freon in to make the system work without pulling a vac first. It just won't work as well that way.

tiger by tail.
read the FSM , see what it says.
not one tool you own , i bet.

go to alldata.com (pop that into google and bingo)
RTM , then ask questions.
IIRC:

1. pull battery cable neg lug.
2. connect collection system to our car and capture all freon.
3. replace line., (unscrew fittings)
4. new receiver dryer.
5. pump down system to a vacuum. (gets killer water out)
6. new compressor oil.
7. new Freon. by weight added.
8. test system.

its more then that. but you can google "car freon loop service" any time. or "car R134 loop service"
1million hits. google is your friend. LOL>
here ill type it for you....

https://www.google.com/#q=car+R134+loop+service

Can be many things. If you are lucky, just get a refill kit for Freon and follow the instructions. If a system is low, there is a chance it can safely be restored with a can of sealer and fresh Freon. But the situation is different for a completely discharged unit. In those cases some interior components may be dried out and unusable.

Freon has skyrocked and where we use to recommend trial and error, the money could be spent for a trained mechanic to do it right.

Against Ferderal Laws to discharge refrigerent into
the atmosphere

That is the may cause of holes up there

You can not install new freon without leak testing.
repairing leaks & pulling a vacuum with a pump
& knowing the theory of A/C Systems

Need a shop that is trained & has the proper equip

It could have leaked out or it could be another ac part. If it is low on freon all you need to do is add some more, no need to change like oil.

IF U HAVE FREON DISCHARGING FROM THE COMPRESSOR YOUR DISCHARGE PRESSURE IS PROBABLY HIGH AND ITS BLOWING OFF. CHECK TO MAKE SURE YOU HAVE THE RIGHT AMOUNT AND ITS NOT OVERCHARGED. FANS ARE WORKING PROPERLY. CONDENSOR IS CLEAN. IF EVERYTHING IS GOOD THEN U COULD HAVE A BLOCKAGE.

Yes you can, go to any auto parts store. Putting vacuum on the system to empty is just to make sure any outside moisture didnt enter the system through whatever leak caused some of the freon to discharge.

You can purchase R134a cans with a built in gauge so you don't overcharge... Assuming the system has not completely discharged, usually a can or less will do. Here is a link with some basic instructions:
http://www.sadik.net/nissan/howto/ac_r134.htm

hi! there,
usually located on high side or discharge presure of the compresor, the discharge service valve fitting equiped w/ cup and pin auto valve ,loosen and remove service cap of service valve fitting,.as you remove the service cap no leak should take place due to it has a pin to locked the pressure on the sysrem . the guage manifold has a host and service port at the end of the host,the sevice port has a tip ball inside port when you connect your pressure guage manifold to test the discharge pressure the tip ball of port will push the pin valve service fitting and opening occued on discharge service valve and the pressure gauge activated and you can the operating discharge pressure.

in your case opening of cap then leakage appear maybe the pin valve was mis aligned or distorted,the service valve was repairable it can repair,but you have to evacuate all freon inside the
system.freon leakage is bad for our environment
use evacuating pump and service tank,after the freon evacuated repair service valve there is pin remover to pull out pin valve sometime cup has pin remover or ask on car air service center.the pin valve has screw type spring attachment replace pin valve and recharge the system you can use the previuos freon on service tank evacuated.