Changing the air condtioner accumulator/filter/dryer

Redneck · Post by **Redneck** » 24 Jun 2014, 04:11

I am in the process of changing evaporator in Volvo 850 1996. I will also be changing expansion valve and dryer/accumulator. Can someone post a link to a write up for changing expansion valve and dryer/accumulator?

I also have a water leak around wiper washer reservoir. It drips on the ground if I fill it up full.

Post by **Ozark Lee** » 24 Jun 2014, 07:37

I went ahead a split out your topic from the evaporator post since it deserves its own topic.

The accumulator is a bear due to the location and the spacing. You need first remove the mounting bracket from the accumulator. Be careful with the upper bolt. I have had the socket slip and I broke the high pressure switch in the process. Once the bracket is removed use your "quick release" tool to open the snap ring and pull the accumulator out from the main line. The tube from the main line has a couple of O rings and it sets into the accumulator a good two inches, perhaps a bit more. The main AC line isn't firmly bracketed and it wants to move as you try to pull the accumulator off. An assistant to press the quick release tool in and hold the main line really speeds things up. I have also found that rocking the accumulator back and forth - essentially spinning it around the tube - will get it to walk out a bit easier.

Once the tube is released you need to let the accumulator drop down so that you can get a pair of very large wrenches on the flare connection. I have a set of extra long wrenches that go up to 26 mm (Harbor Freight Specials) that work well along with a pipe wrench. Replacement is the reverse and it goes very easily if you lube the replacement O rings with PAG oil.

As far as I know the Volvo system uses an orifice tube rather than a thermal expansion valve. I have never had a compressor grenade on a Volvo so I have never changed the orifice tube. I'm sure someone who has will jump in.

...Lee

Post by **Ben850** » 24 Jun 2014, 08:34

Timely post for me Redneck. I was about to do a search to read up on the subject. I had just received my accumulator/dryer from FCP for my wagon.
The old one actually blew open at the bottom from rust while I was charging it last summer. The model I have from FCP seems to be all aluminum, so I do not foresee a rust problem with this one.

Redneck · Post by **Redneck** » 24 Jun 2014, 14:01

Thanks Ozark.
I bought all parts: Evaporator, orifice tube, dryer, two valves, all seals etc. Everything Volvo OEM. While I am changing the evaporator I am doing all that is in the way at the same time. I hope that no special tool is needed to remove the old orifice tube.

Has anyone replaced the two valves? The one that feeds freon and the one by the evaporator? I have new valves, but im worried that as I unscrew them, some piece of old valve oring or seal will fall into the pipe and travel in the system clogging things.

I have the AC system open now at the evaporator pipes. I put rubber gloves on it to cut the air. It will be open like that for about 6 days. I hope that when I vacuum pump the system later it will boil all the moisture out. I hope that the moisture absorbed by the hygroscopic oil will allso boil out. What do you guys think? I have no choice:) so it better be good:)

Post by **Ozark Lee** » 24 Jun 2014, 14:29

As far as I know the only thing you need to replace the orifice tube is the quick release tool.

A vacuum should remove the moisture. Hold off on installing the new accumulator until the very end since it will absorb moisture as it is open to the environment. The dryer itself should trap any remaining moisture that is in the system after you pull a good vacuum.

...Lee

Redneck · Post by **Redneck** » 24 Jun 2014, 15:48

Ozark, is the "quick release tool" the A/C line spring release disconnect tool that I used to separate the A/C lines from the evaporator and the same one that I will use to separate the A/C line from the dryer? From the pictures that I saw it looks like the orifice tube just slides into the pipe.

Yes, I plan to put in the new dryer right before closing the system and vacuuming it. I also plan not to pour any oil directly into the dryer as I want to pull all moisture out of the dryer as well. The dryer I have may have had open outlets and could have absorbed moisture. What do you guys think about that?

Post by **Ozark Lee** » 24 Jun 2014, 16:12

The spring clamp tool is indeed the quick release tool. On the dryer, I much prefer to have them sealed up when I get them but I have installed a couple that the cap fell off in transit and I have had no problems with them. If it was something that you sourced locally I would see about returning it but if it involves freight, return authorizations, etc it probably isn't worth the hassle.

...Lee

Post by **JDS60R** » 24 Jun 2014, 20:11

You can grab the end of the orifice tube and pull. If stuck some needle nose vice grips or a drywall screw through the middle and some persuasion normally gets it out for me. An orifice tube removal tool is available as well at around $15 ( The drywall screw is not a safe way to do this -some of us old mechanics do silly things and we know better) . Please don't scratch the area inside the tube where the o rings would seal or slide over to get to that position.

Redneck · Post by **Redneck** » 25 Jun 2014, 01:28

Does the orifice tube stick out enough from the A/C pipe to grab it with pliers or a vice grip? or is it completely inside the pipe?

Is the orifice tube stuck inside the A/C part of the pipe that connects to the evaporator? I have that end of the A/C pipe disconnected because I am also replacing the evaporator. This would make it easy as I could hold the pipe with the orifice tube inside in any orientation and attempt to pull it out.

Post by **abscate** » 25 Jun 2014, 04:22

On my 1999 the tube is removed from the AC line running right in front of the timing belt with two large (19mm) union nuts. Break the union, then just pull the tube out with needle nose pliers.

Note orientation, I put it in backwards the first time