Hi All,

I have a 1989 245 that the A/C does not work in. Recently, the A/C clutch came apart and made less than good noises and started smoking. I know there are leaks somewhere in the system, because the last time I tried to charge it, the air worked for a day or so. So I bought a new compressor, drier, expansion valve, and seal kit from rockauto.

Everything under the hood looks to be fairly straight forward as the replacing of parts goes, but I am at a loss as to where the new expansion valve goes. I am also looking at where the hoses go into the firewall and fear needing to take the dash or at least most of it out of the car to get to any seals inside. So, where does the expansion valve go, and does the dash need to be removed to get to anything inside the car? What else should I be doing to make this a successful repair? Any points and additional information would be appreciated.

Thank You!
Eric

Hi there!
Getting ready for summer I see!

The expansion valve is accessed from the left side of the passenger side foot well.
No need to remove the dash!
It will be on the smaller line coming through the firewall.

Note the location of the sensing bulb location on the return line. It needs to go back there for sure or a little farther away I have found works a wee bit better.

On a horizontal line is goes at a 45 degree angle from the bottom. Anywhere "around" on a vertical section of line. Oil travels on the bottom of lines and you want to sense the gas!

Insulate everything as it all gets cold and sweats moisture out of the air.


I take it that the compressor locked up and that is why the clutch smoked!

The need to remove the expansion valve is because, in all likelihood, there are metal particles spread throughout the system.
If the dryer screens missed any, the expansion valve can get plugged up.

You will have to flush about a quart in to rinse out all the lines in the system or the warranty will not be any good on that new compressor.

While you have the compressor out, the dryer out and the expansion valve out, that is when you push a solvent through the lines.
Some people use refrigerant to push with but any dry (free of moisture) inert gas like nitrogen, argon or helium for example, can be used if you are a welder type dude!.
Even propane if one uses some thinking and exercise extreme caution of where it comes out in the rags.

Did they sell you some of that as well?
If they did not, keep your receipt from whomever you purchase solvent from.
You use it to prove that you did this very important part of the repair!

The six ounces of compressor oil will be enough for the system as the system is sized for that compressor or vice versa.
Whatever refrigerant you are using, you have to have a compatible oil in that compressor. Don't forget to put it in!

Did the compressor come with a bottle of oil?

Do you have a vacuum pump for the evacuation & leak test phase before recharging?

While you are taking things apart look for any places that show an "oil sweating" joint or surface! That may help you find where the leak was!

I looked for a long time for a leak. I found mine under the clamp that hold the dryer/receiver canister.
Volvo had put rubber under it to reduce possible noise but instead it held moisture there.
Don't use a foam type rubber if you need a spacer!
Pin hole rust leak!

That's about all I can think of of the top of my head.
Hope this helps!

Phil

So, I got back to this project after a few weeks of other work.

I did not see where the sensing bulb on the evaporator went entirely when I pulled it out, and the new one is a different shape and size. It also has about 4 inches more soft copper line than the old one. The original is a coiled up soft copper line and the new is a bulb that is elongated. Where should it sit in the housing and where should all the extra line go?

Also, I pulled a bunch of this sticky insulation gunk off the lines. It came off in chunks and made a bit of a mess. What can I replace it with?

Thanks again,
Eric

Hi there Eric,

Yes you were gone from the project awhile. That why I take pictures of a lengthy project to help me remember how it was done before.

As I remember you were going to change out the expansion valve. So you are talking about the sensing bulb from the power head of it. The term "pulling out" is twisting me a bit.

It could mean you removed the de-icing/ cabin temp. thermostat capillary tube from inside the cooling coil. It just fits between the fins or you pulled off/out the expansion valve as a unit.

In the latter case, you should have had to unclamp the sensing section or tip from the suction line that goes back to the compressor.
The whole valve and the sensing tube should have been covered up in that "sticky stuff." That sticky stuff can be had from an auto parts store. It comes on a roll and is made of a tar substance and cork. Or more modern methods are, you can use a closed cell foam tape that has adhesive on one side and wrap it with that. Anything to insulate air, that contains moisture and heat form the body of the expansion valve and the sensing tube body.

The sensing section, no matter what shape its made in,is needs to be held tightly to a place on a metal section of the suction line as I explained in an earlier post above. As much surface area you can get in contact with the tube the better. That may be why you describes elongated or flattened out?

As far as the extra length of capillary tubing you need to roll it up. Do not "kink" this line what so ever!
What I do is to roll it smoothly around something.
If you can find a small bottle, like prescription medical pill container, that fit up into the area of equal to (level or lower) with the TXV. Spin excess around that.
Pick a container as large as you can find but fit there.

The less you bend the tubing, the softer it will stay, as bending it work hardens the material.

Leave enough length of tail that you can turn the tube tip end going downward from the coil if you have the room. A gentle slope between the will be fine as it's not that crucial.

These are just a few quirks that I have!

This is so that the gas or liquid droplets inside the tubing will flow to the tip, by gravity, to sense the suction line.
Otherwise, part of the sensing liquid can get trapped in the turns going back to the power head.

"Optionally insulate" the coils lightly as their surface area will not condense great amounts of moisture anyways but it does keep the readings more accurate. Again not a big deal!

I think you are doing a great job on your learning curve because you are asking the right questions!

Phil

The expansion valve is under the dash on this car. It attached to the AC lines that came through the firewall and the sensing bulb went through a hole in a housing directly behind the center stack on the dash. The line the sensing bulb is on went into that housing and was not attached to anything. I can't see in the housing very well to tell where the old sensing bulb was sitting, but the new one doesn't have much room to go in there. I just sort of stuck it in there in the general area that the old one came out. I just am hoping this is okay. If not, I haven't insulated or replaced the interior parts yet.

I did keep from kinking the copper, but it is in a vertical coil next to the housing I was talking about. Does the direction of the coiling of the copper matter?

I did find out the what the material that was wrapped around the old expansion valve was and will get some soon.

I got the drier changed out and new seals everywhere a connection was broken and made. Still working on getting the compressor out. The In-laws stopped by last night and so I stopped working on it. I hope to be back on it tomorrow evening.

Side note, I did get the exhaust on both the 626 and Volvo changed, the fuel pressure regulator, rear anti-sway bar end links and an oil change done on the 626, as well as replacing the rear shocks and rocker molding installed on the Volvo. Progress is slow, but it is happening.

Thanks again for walking me through this. You are appreciated.
Eric

Hi Eric,

You have been a busy man with those other repairs.

You mentioned that you put the dryer in already. I wish you had not done that right away.
It should be the last thing replaced.

If you noticed when you pulled the sealing plugs, there should have been a slight pop/whoosh noise. They are usually filled with a dry gas to keep moisture out.

You should not leave the system open to outside air as it will absorb moisture out of the air.
Keep ALL your lines buttoned up or plugged when you are not working on it!

The dryer should be limited to about 30 minutes of exposure to the atmosphere.
If you exceed that time allow, extra time to evacuate with a vacuum pump.
You might want to use a common hair dryer to heat the dryer container up to help boil off any moisture that was drawn into the desiccant.

No need to buy a new dryer as the desiccant has not been exposed to any oil from the system.
Oil can absorb moisture but does it slowly and gives it up very reluctantly.

The big fear about moisture in the system is corrosion but more importantly that it freezes.
This happens at the expansion device and plugs the flow of refrigerant. Cooling stops until that drop or less thaws! Then it goes around again and again if the dryer does not catch it.
Dryers are rated by the number drops than can retain.

The next thing that I am still confused about is your description of which sensing bulbs are going where. Maybe you have not found both or I am dense.

The dash thermostat has one that gets push directly into the coil fins. A small hole in the side of the plastic housing.

The TXV bulb, that come off the very top, must be attached to the tailpipe line coming out at the bottom of the housing going back to the engine compartment.

The bulb cannot be hanging out in the cabin air. I needs to sense the returning refrigerant from the evaporator coil otherwise it will flood back to the compressor.

The direction that the coils winds makes no difference.

Its just the end piece that I like to be pointed downward from the coils or upwards if the coils are below it. This is only a factor on a vertical line attachment position.

It's just a way I want to handle the operation or behavior of the gas in that tube.
It was a technical discussion back in my schooling days and a habit or quirk today!
In most cases, a person would not notice a difference but it can affect sensitivity.

I like to push a little more flooding of filling of the evaporator to have it available to remove heat.
As you know these evaporators are a bit undersized.

I actually tune mine. I move the bulb down the line farther or use a thin plastic insulator under the bulb. I read pressures and temperatures differences on the suction line with a infared thermometer to find what is called that area where "superheating" occurs.
It a way to assure there is as much liquid is in the upper half to two thirds of the evaporator and control the boil off or flash point back to the compressor.
A factory attachment uses a mid range point to average climate humidity differences world wide.

On our cars you can get up to about a five degrees more heat removal improvement by tweaking. It helps but the system will not give you ice cubes! It's not suppose to, it's just comfort!

Keep going, summer is coming!

Phil

Hi Phil,

I kind of figured I messed up a bit when I pulled the plugs on the drier and the gas escaped. I do keep the system sealed when I am not working on it, though so good to know I am damaging things a little bit instead of a lot a bit.

As for the sensing bulb, I probably have not found both, as you being dense is entirely out of the question. The only one I have seen is the one attached to the expansion valve under the dash. I didn't know there was another one. I'll keep an eye out for it.

I did find some self adhesive rubberized pipe insulation for the expansion valve, so I'll get that on when I re-aim the bulb. I probably won't get as advanced at AC tuning with it as you have. If I can keep passengers from melting down in the summer, I'll be more than happy.

Thanks again for all the fantastic info, and I'll keep you posted.

Eric

Big relief on this end about the dash staying where it is. Good to know.

The A/C system was not on when it was smoking which is what is a bit confusing to me. So, the stuff you push through the lines would be the inert gas? A quart of what do you push through with the inert gas? Sorry, I'm not well versed in things A/C related.

What would you recommend to insulate the expansion valve when I install it?

I didn't see any oil with the compressor. I plan to install the parts and take it to someone who knows what they are doing and has the equipment to properly oil and recharge the system.

I will look for the leak while going through the system. I wasn't sure what to look for in particular... until now. Thanks!

Thanks for the great response and the time getting me all this good info. I am trying to get the car back on the road. When I do the A/C service, I also have the parts to replace the leaking steering rack and tie rod ends, the ball joints, all the shocks and struts, clips to reinstall the rocker moldings, and convert it to an M47. Once that is all finished, I'll need to see what needs addressed next.

You have asked very good questions and the plan to take it to someone with the equipment to recharge the system might be best overall.

I can understand to the laborious wrench turning to save money as well!

Since you were not using the A/C system I don't know how the clutch went bad unless the magnetic coil shorted out internally. That would have been very hot or stinky for a short time.

Can you still turn the crankshaft of the compressor?

When you remove the compressor, open the fill port, on the topside of the housing. You will only see a head of a bolt there. Dump out any oil and see if there is any shiny metal particles in that oil.

If it is clear, then you "may not" have to worry about flushing the lines and coils.

Just keep track of how much oil you remove from the compressor and tell the tech that upon refilling the system.
He can adjust for any left over in the lines and the dryer can.
A little extra oil only reduce the liquid charge amount and on your system that not a big deal.
You have an expansion valve and receiver dryer space!
On 1991 and later cars, with the CCOT system, you might notice an efficiency difference.

All together it's probably a couple or three ounces, plus what you poured out. Remember it only needs six ounces.
I expect about four ounces of retrieval would be an average. The old dryer desiccant package holds the most.
You might ask the tech if he wants you to put it straight into the crankcase of the compressor or just let him decide how he wants to control that. It's easier on the bench is all.
Just don't forget It!

As far as what liquid to use to flush that is a subject that has many answers.
In the old days they use to use R-11 refrigerant. It stays a liquid at room temperatures.

I worked at a place for about three years where we had a certified aerospace "clean room."
We made special stainless steel "clean valves" for the handling of exotic gases used in the making of IC computer chips by Texas Instruments, Fairchild and Intel.

We had a parts cleaning "vat" filled with it, to clean parts in.
I used to dip my safety glasses into the upper vapors just above the liquid. The liquid condensed on the lenses and wham, rinsed instantly cleaned. No oils or crud anywhere!
I think it could even suck the petroleum oils out of the plastic, if you left them in there long enough. They become white-ish?
No wonder, to me, why the Freon's got banned. Electronics and packaging companies abused the stuff!


It is still offered in the refrigeration trade but now, it is really expensive and off my list!
In the past, some techs, not me, just blowed down the lines with a straight liquid refrigerant dump!
That is a no-no nowadays!

What you want is a product or liquid that will dilute the stickiness of left over oil and create a scrubbing turbulence while passing through the tubes and lines.
It also need to evaporate easily and "Boil off" under a vacuuming evacuation.

I have used denatured alcohol, as it also absorbs moisture and is cheap. I also used a heat gun to warm things up in any low spots of tubes while vacuuming.

There is other automotive cleaning solvents that are a grade above paint thinner and kerosene but about $9 a gallon. It will evaporate well!
I keep a five gallon can of that around for my special cleaning projects.
Some people use acetone or even lacquer thinner. The last two are way hotter solvents and I don't care to use them on cars since they have rubber hoses involved.
I know it's short term it just bothers me and it stinks more.

Hopefully you won't have to get into it!

Those other Addresses,you have going on with this car, will keep you more busy than living in a Urban area!
(:-)

Phil

I can't tell you how thankful I am for you imparting you knowledge to me, Phil.

I am taking a short break on the Volvo to repair the 626 so I can loan it out for the summer. In the mean time, would it be best to talk with the shop I choose to have recharge the system to see how they want me to proceed in getting the oil back in and what oil they want me to use? I am under the assumption that I will be going to R134a when recharging. Is there anything I need to do to change over while replacing parts? I think I remember reading something about having different fittings for the different refrigerants. How can I check to see that I have the correct fittings?

Yes, it would be best to discuss what he needs to service your system!

The oil has to be compatible with any refrigerant.

The fittings would help keep someone from mixing refrigerants later on.
That would be a big no-no to have that happen!

He is your partner and he will do good by you, as I think, because you have taken such an interest!

I hope as you are better informed now and have more confidence going forward.

You are welcome.
Glad I could help!

Phil

one of these files may help

http://www.volvowiringdiagrams.com/?dir=volvo/-%20Service%20Manuals/Heating%20and%20AC%20240

Thank you! There is a ton of good info there that I can refer back to for all kinds of things in the future. Much appreciated.