A/C Recharging Procedure

firstvolvo · Post by **firstvolvo** » 27 Sep 2006, 10:34

Hello everyone, I just bought my first Volvo and found this great forum. As when I bought my first BMW, I'm now finding out I got into the first year production of the S80 (1999), so I can apparently expect a myriad of bugs and issues - just my luck. Fortunately, the PO took care of many of the known issues already, and the car does run quite nicely.

I have noticed that my A/C compressor is cycling quite frequently, so I decided to recharge it. Per VADIS, you recharge on the HIGH side, opposed to the low side, which is how I have always known to recharge an A/C system. In looking at forums for other Volvo models, they recommend recharging on the low side. Anyone know if the S80 T6 can be charged on the low side, or how do you go about charging on the high side? Anyone here done it before & care to share your procedure?

Second, how do the caps on the lines come off? Do they unscrew, or just pull straight out?

Thanks in advance and I'm glad to be part of your forum.

firstvolvo · Post by **firstvolvo** » 10 Oct 2006, 16:12

Since I had no luck finding information on this and no one replied, I decided to share my experience, hoping it may help some of you out there.

Per VADIS, the A/C system should be recharged on the HIGH side. Finding this to be not only odd, but dangerous, I recharged my sytem on the low side (port is underneath the power steering reservoir). Per other posts I read, it's impossible to overcharge, since the DIY kits available at local parts stores do not allow for overcharging-they simply stop transfering refrigerant when the maximum system pressure is reached.

At first, I added one can, and the frequent cycling of the compressor stopped. However, the air did not feel very cold. System pressure was near 30 psi (when compressor was running). I decided to add a second can. However, while ading the refrigerant, my compressor disengaged, and started cycling, staying on for only a second or two at a time. After I got the second can in, I let it run for a while, and the compressor would only come on for a second or two at a time. Later that afternoon, when I wne to start the car, I got a bunch of smoke from under the hood. When I opened it, I could smell it was refrigerant. I was not able to determine where it was discharged from.

For the next couple of days, I had no cool air from the A/C. I went back and released as much air out of the low side port, without allowing any of the refrigerant to escape (only the air pressure). Now my A/C runs fine, and the compressor hardly cycles on and off (it consistently stays on).

From what I can tell, the system holds less pressure than what the dispensing cans allow, and the air needs to be let out of the system after a recharge. I guess I overcharged it and somehow there's a relief valve somewhere in the system. It is currently at about 32 psi. I hope this helps some of you out there coping with the remaining hot days without A/C.

Post by **matthew1** » 10 Oct 2006, 17:34

beautiful tips, firstvolvo. thank you. I'll add a link to this from the official Volvo AC Page.

RajDog · Post by **RajDog** » 25 Apr 2007, 17:23

I was wondering how you released the air without the refrigerant? I have an s70 and I put 2 cans in and the ac showed no improvement. I'm thinking about trying duracool this summer.
Thanks

dynamok · Post by **dynamok** » 09 May 2007, 12:28

I have a 2000 S80 and I'm trying to refill the freon.
So the valve on the radiator is actually a high pressure valve? I though that the one hiding really low past steering pump and electric box is actually the low pressure one?
I couldn't fit the adapter on the high pressure valve, does the adapter fit on the low pressure valve?

gameboo · Post by **gameboo** » 15 May 2007, 21:51

how exactly do you release air from the system?

Thanks.

dynamok · Post by **dynamok** » 16 May 2007, 09:20

Actually had it done professionally. Not at Volvo dealership, but a guy I know. $100 to charge it with sealants.

Post by **vegasjetskier** » 21 Dec 2007, 09:01

ALWAYS charge on the LOW side, never the high side. The high side pressures are enough to blow your little can of freon sky high, causing you severe injury. This is why the high and low side valves are different sizes and the little kit you buy from your auto parts store only has the low side valve on it. To charge correctly, you really need a set of gauges so that you can measure the high side pressure and bring it up to factory specs as you add freon (unless your system has a sight glass, then just add freon until the bubbles in the glass disappear). You can get gauges at your local auto parts store or from HarborFreight here: http://www.harborfreight.com/cpi/ctaf/d ... mber=92649

When you let gas out of the system, it is not "air," it is vaporized refrigerant. It is illegal to vent this gas straight into the atmosphere as it is a greenhouse gas and contributes to global warming. The gas must be recovered by a machine that costs about $600. So it is best to just add freon until the system is full and leave it at that.

It is very possible to overcharge from the low side. The pressure in the can could be up to 100 psi, yet the low side of the system is only 0-40 (the pressure differential is what forces the freon from the can into the system). Without a gauge on the high side, you have no idea how much freon is in the system.

Firstvolvo, it would seem that you overcharged your system and caused a leak somewhere, probably a compressor seal, that vented the excess freon. You're lucky your system is still working.

sheaton · Post by **sheaton** » 29 May 2009, 13:48

Just recharged the aircon on my Volvo S80.
I bought a bottle of R134A and a set of professional gauges with a quickfit adaptor for the high side and a sight glass. The quickfit adaptor has a screw-down pin which opens the high-side valve when required. Vadis specifies filling from the high side only – not sure why.
The high side inlet is on the condenser. What you need to do is “pour” liquid R134A through the hoses into high side inlet.
IMPORTANT: DO NOT RUN THE ENGINE AND DO NOT USE CAN TYPE QUICK FILLS ON THE HIGH SIDE.
Procedure
1. remove the cap from the high side valve (22mm).
2. connect your quick-fit high side coupler (I had to modify the slam panel slightly to allow mine to fit)
3. connect red hose to gauge manifold
4. connect yellow hose to cylinder
5. screw down valve on quick fit adaptor; red gauge will indicate some pressure
6. open red valve on gauge block and loosen fitting on cylinder slightly. Use some of the remaining gas in the car to purge the line.
7. weigh the gas cylinder and make a written note of the weight
8. open the valve on the gas cylinder and turn upside-down
9. fluid refrigerant should flow through to the condenser (check the sight-glass)
10. allow flow for 10 sec, close the valve on the cylinder, and re-weigh. Loss of weight obviously confirms the transfer is taking place.
11. repeat until 1000g has been added
12. open the screw-down valve on the quickfit connector and disconnect the connector. Replace the high-side plastic cover.
13. Colse the valve on the cylinder, and very carefully release the line pressure.
Notes
Always wear gloves and goggles throughout the procedure
Refrigerant will only flow into the condenser when the pressure in the refrigerant bottle is higher than the car. You may need to warm the refrigerant cylinder in a washing-up bowl of hot (50C) water for a few minutes.
Following the recharge, the aircon was dropping the incoming air temp by 12 degrees Centigrade.

greencupbay · Post by **greencupbay** » 03 Jun 2010, 16:37

So, I have been reading around and found that people say to only refill the A/C on the High Side port for the s80's. FirstVolvo, you said that you refilled the a/c on the low side and it made a difference on how often the a/c compressor turned on and off until you overfilled it, but it never made a difference in the temperature of the a/c? After your car smoked and you released some r134a, did it then make a temp. difference? If it doesn't make a difference in temperature, I think that I might have to get this one professionally done because I don't have a high side kit. Also, is there a watch glass? Thanks in advance.