Difficulty: easy
Tools Needed: AC Block Gauge (with quick connects and hoses) and Vacuum Pump (available inexpensively @ Harbor Freight Tools), R134a brass shut off, Green Dye (checking leaks, optional), Meat Probe, Kitchen Scale (not pictured). **Disreguard rachet, sockets and wrenches in below picture).
Time: (relaxing) 2 hours


**This procedure was done to a 2005, 3.0 litre, S Type with a complete evacuation of R134a Refriderant.** The following instructions will give you basic knowledge on how to recharge a repaired HVAC system.

It has been brought to my attention that people are worried about confusing HIGH Preasure and Low Preasure Lines. There are only 1 of each on this model. The quick connects on vehicle are different sizes, there will be NO confusing the smaller of the 2 which is the LOW Preasure Line. Red = HIGH preasure line, BLUE = LOW preasure line.




Locate the "low preasure side" (smaller of the 2) AC line quick connect. In my case behind drivers side (US) front tire. Connect the vacuum pump to the low side line. Vehicle does NOT have to be running. Turn pump on and let run approx. 45 minutes. There isn't a guage for letting you know when the air is sucked out on the pump I used. Good time to enjoy a few cold beverages.



Locate the AC System Sticker under hood which will tell you how many grams or ounces to fill your system, (ours is located on radiator splash shield). I needed 2-15 oz cans of R134a.



Moving on. Close Blue quick connect valve or disconnect vacuum line from AC system BEFORE turning off vacuum pump.

Heres where it gets tricky. Using the kitchen scale weigh the can of R134a WITH the brass shut off valve fitting secured to the can and hose attached. Connect to low preasure side quick connect, again an acurrate scale reading here is important!


(In the above picture, note the short blue dial gauge connected to the R134a can, I borrowed the AC Block gauges from a fellow member and it was missing a fitting to use with the long blue hose. I had the short line laying around (cheapie) from a big box store, that I ended up using)

Start vehicle, turn on AC, full fan at coldest setting. Following the R134a can directions I tilted the first can back and forth, approx. 10 minutes until empty. Close shut off on brass can fitting. WEIGH empty can and write down or remember figure. Attach second can of R134a, open shut off and let fill again keeping watch on the weight. About midway through can #2 the compressor kicked on, continue filling.

Using meat probe in a vent monitor temperature reading, until a temp between 39 and 44 degrees is displayed.



Close brass shut off. Add up total weight of refriderant added to system. If the total weight meets your AC System label, Congrats your finished!

AC Block Gauge reading after buttoned up





A BIG thank you goes out to fellow member Androulakis (George) for taking the time for explaining and holding my hand through this procedure!!

Also a BIG thank you to fellow member 01stype30 (Nick) for loaning me his AC tools!!

 

Rick you wont get below 50 degrees UNTIL you turn on the recirc button, BUT you don't want to do that until you are pretty much fully charged... Remember

When you hook up the first can, the A/C compressor will not be engaged. As it starts to take the charge, with approx 2/3 of the first can gone, the compressor will fire up, and you should see about 62-65 degree air out of the vents.

Two things to note.

1) Shut OFF the car between can changes.
2) When the temp stablizes (stops dropping), pick up the can, move left to right. Finally invert the can to get the last bit out.

Take care,

George

 

Another great write up / how to c/w pics Rick and it needs to be made FAQ.
I'll change the thread title to FAQ and I'm sure one of the mods will add it shortly to the FAQ base.

Note - perhaps George's add on comments should be edited into your thread, ie- notes 1 & 2

Its fantastic to see 3 forum members, yourself Rick, Androulakis (George) and 01stype30 (Nick) all working together on this....excellent!

 

I've added the link to the FAQs.

Nice job Rick, I'm glad to see that you worked an opportunity for a cold one into the process.

 

At ALL times!!!

 

i guess ill be aiming for 40 something since ill be moving to arizona pretty soon

 

42.4 is pretty chilly!!!!! Even here on a day like today that hit 96 degrees and 81% humidity.

 

Excellent thread , happy cooling lol

 

Hi Rick,

Excellent write-up and pictures. A couple of questions.

1. What is the psi on the low-side port? It looks to be 40 but I wasn't sure.

2. What was the ambient temperature when you did this?

There are some kits that have a psi limit for a given ambient temperature. As an example 55 psi at 90 degrees F.

Thanks in advance,

Mike

 

Correct Mike, low port is at 40 PSI.

It was 96 degrees on the day I charged the system.

There was nothing noting on the cans of R134A that stated any type of limits.

Hope this helps you

 

Thanks Rick,

It should help. One thing I noticed is that the R134 cans come in 11 oz cans (coincidence)? The kits I saw at Advanced Auto Parts were a hose kit with a pressure gauge. The directions indicated what the psi should be for a given temperature. I can use your 40 psi as a rough guide and adjust off that.

Mike

 

Don't forget to rotate the can left to right or vise versa, when the can is almost empty I believe you flip it upside down to get the last of the refridgerant out.

 

Mo' bettuh, dip it in a vessel of hot water. You want to raise the vapor pressure in the can above the suction pressure to force the maximum amount of gas into your system.

 

Except do not overfill!!

You are at risk of doing so if you don't weigh what's in first.

 

Just curious. Did you add any compressor oil? I just replaced the compressor on my F250 and it needed a total of 9oz of compressor oil?

The new compressor had 6oz in it. So I had to add 3 additional oz.

How much compressor oil does the S-type need? I'm about to replace mine TOO.

 

Also, did you replace the dryer and expansion valve? Most places will not warrant the compressor if these two parts are not also replaced!

 

Usually you weigh the oil in the old comp and make sure to have at least as much. Or if you're lucky the workshop manual tells you what to do (try JTIS lol).

I've only met places wanting the dryer replacing but then I have never actually wanted a comp. warranty

 

...I know its an old thread, but very useful. Can someone please answer the question OP had asked. Noticed noone answered his question and I'm also wondering the same thing about adding a/c compressor oil.

** IF I take it to the A/c shop do those a/c machines have the compressor oil mixed in with the refrigerant?? or I have to manually have them install the Compressor oil before filling it up?

Thanks..

 

Charging stations have the ability to add oil but it isn't in the bulk gas gas bottle. It really depends on what components are changed out. A replacement compressor will typically state if it is oiled or requires additional oil. Most of the oil in the system settles in the accumulator drier and compressor. When fixing wrecks, I frequently change out condensors without adding oil. Too much slogging about can be as bad as not enough. Unless you completely evacuate and flush the entire system, there is no way that I know of to tell exactly how much is in the system.

Hope that helps.

 

Here's the chart from JTIS. it's the same for 3.0 & 4.2.