Replacing A/C Receiver/Drier

jweston01 · Post by **jweston01** » 19 Jul 2011, 10:38

My A/C Drier has a small puncture and sprayed out Freon last night. Is there anyone that can walk me through the process? And is imminent that I must vacuum the system out before putting a new Drier in? Any help is greatly appreciated. Thanks in advance!

Post by **erikv11** » 19 Jul 2011, 10:47

I have not seen a walkthrough for replacing the drier. Basically now that the pressure is released you need to:

1 Disconnect and remove the drier. Getting to the fasteners is a pain on the 850s, likely the same on your '00 S70. You'll need some kind of spring-lock disconnect tool, I bought a cheap set from Autozone that worked well.

2 Add the proper amount and type of PAG oil to the replacement drier (search for this info ...). Minimize the amount of time the drier is exposed to atmospheric air, it will become contaminated with moisture and be useless. In fact I plugged all the AC lines with rubber stoppers while I was working on the car, just to minimize moisture contamination. There are a lot of makes of drier out there, I did not want to be doing this job again so I bought the Volvo branded one.

3 Reinstall. This is a good time to replace any o-rings on the parts you disassembled. I would get a parts diagram from one of the online Volvo parts dealers. Many people also replace the expansion valve at this time. I did.

4 Pull a vacuum to evacuate the system of air and, importantly, moisture.

5 Recharge with the proper amount (by weight) of r134a. Again, you can look this up.

Steps 4 and 5 some people go to a shop for, they are of course set up with gauges and fittings to do that quickly and properly.

jweston01 · Post by **jweston01** » 19 Jul 2011, 11:02

I really appreciate all of your help. Will attempt shortly, hopefully all goes well. Thanks!

Post by **erikv11** » 19 Jul 2011, 11:08

For the PAG oil you are only topping off the system. You only need to add the amount that was lost when the oily-laden drier was removed. This can be looked up.

But for the refrigerant you need a full charge, all of it has escaped.

There should be a sticker under the hood that tells how much refirigerant, and what type PAG oil, is needed. Sometimes the PAG info is on the back of the AC compressor.

kevins s70 · Post by **kevins s70** » 22 Jul 2011, 06:31

I am also replacing my drier (S70) as it is rotted. Is PAG oil poured into the drier or is it added when the system is evac and recharged? thanks.

Post by **wheelsup** » 22 Jul 2011, 13:27

I did this job. It was easily. Go from the bottom of the car with a large adjustable wrench on the nut. The disconnect line is easy, you buy a cheapie disconnect kit at autozone or something, I remember they normally are color coded and mine is black. I believe they are also known as Ford tools. Anyway, once you get the drier out, you can pour out the oil in it and measure it to see how much to add. Or you can do what I did and just buy the 134a cans with oil already in it. There are several different grades of PAG oil, to be honest I didn't know that and so far after 6 years it really hasn't made a lick of difference.

Technically you are supposed to measure by weight how much 134a to add. The truth is, the system will stop taking it once it is full. Just add it, you will need at least two of the smaller cans. You probably won't use all of the second can. Buy one can with 134a + oil and one just 134a, that will be fine.

Post by **erikv11** » 22 Jul 2011, 16:08

I disagree with several comments in the last post:

- there is no mention of pulling a vacuum. True the AC will work if you don't, but all of the moisture in the system will render the drier useless. You won't know that it is useless until the AC compressor dies. That's an expensive part.

- the system will not stop taking refrigerant when it is full. You can easily overcharge the system.

Since the system is instantly and completely empty of refrigerant the second the drier is unhooked, why not add back exactly the right amount? This is not a difficult amount to find out or to add accurately, I am away from my car or I would just go out and look it up.

- you can not reliably measure how much oil is in the drier by pouring it out. Think about dumping 50 ml of oil into a container, then pouring it back out. A significant fraction of the oil would stick to the sides. Especially on whatever is in side the drier, maybe dying chips I don't know. Volvo publishes figures for how much PAG to add for each component, and you can look it up by a search on this site (MVS). Also be sure to use the correct weight PAG oil, there are 3 different weights.

- using the pre-mixed oil+R134a is not a good idea if you really don't know how much oil you are putting in. Using canned R134a+PAG is OK if you pay attention to how much oil is in the can and it happens to match exactly with the amount you need to add back.

Basically wheelsup is recommending to just make educated guesses about the PAG and the R134a. If all you want to do is get through this summer then guessing will likely work just fine for a while, or maybe even for longer (6 years for wheelsup) if you are replacing only one component and this is the only time you have to open up the system. But if other service needs to be done down the line, and this approach is used a couple times, you will eventually have no good idea of how much PAG oil is actually in the system. That's going to require an expensive cleaning at a shop to get it all out and add back in the right amount. I just wouldn't guess when you don't have to. Why not measure it and be sure? I think I mentioned, AC compressors are expensive.

mezz0 · Post by **mezz0** » 27 Mar 2019, 12:26

Hallo,
Im searching for a writeup/tutorial how to disconnect the line from the dryer going to the Firewall. I have the 3/8 Black disconnect tool. With this i can disconnect this line from the firewall, but not from the dryer (ok Looks rusTy) Its line Volvo number 9171406
Or do i First have to unscrew the dryer from the holder?

Worst Solution would be to buy a new line 9171406 and break it loose from the dryer....

Its a 95 850 20v Wagon manual

Thanks for your help

Post by **abscate** » 29 Mar 2019, 04:56

The 9171406 hose runs from accumulator to evap, Lowe pressure side I see going to run about $200

You need the ac tool on both ends to release the spring clips and then work the double Orings tube out.

Three parts on releasing these.
Remove plastic retainer
Spray in pb blaster To lube spring
With AC tool, expand spring
Vice grip with slight twist to break pipe free And then pull out of fitting

These can be tough.

It’s easier to pull the accumulator off the pipe than the reverse, after removing the mount hardware

Three pipes converge at the frame member behind the headlight. That 6 mm hex internal bolt can break off which sucks. Hit it with PB a week before the job, and replace with new Volvo hardware for $2

You can attack the accumulator fittings a lot easier by removing the fitting at the back of the compressor , the n lifting the accumulator up and on top of the radiator where you can get real tools on it , after you get the low pressure hard line off.

I’m going to say it’s really hard to get the accumulator threaded hardware off in its mounted position. Those suckers rust on really well. Putting a 24 mm or bigger crows foot on it is a laugh as the torque will snap off the frame member mount in a jiffy if you don't counter hold the accumulator from below with something like a chain vice grip.

For a long life expectancy car (>3 years) seriously consider sawing off bad components and swapping some money for time/busted knuckles.

Getting a nice working AC back on an old car for summer will make you feel all Volvo all over again.

Lots of pictures in this idiots thread...

viewtopic.php?f=1&t=56005&hilit=AC+evap ... e&start=30

mezz0 · Post by **mezz0** » 29 Mar 2019, 10:00

Thank you with dryer i meant accumulator. The 6mm allen bolt which holds the accumulator bracket. I got loose with a Special Spray Called caramba rostlöser extrem. I will now try to unscrew the line accumulator to Compressor and loosen it at the ac comp. Then get. the accumulator line from the firewall (mi problem) or cut the accumulator from this Click line. And try to get the rest from the accumulator with pliers and the Black disconnect tool.
Will report this weekend