My a/c compressor seized last week. It was only operating for about 2 minutes after it seized up. I will be pulling it out this weekend. I will also be removing the lines from front to back to clean them out. I got a used compressor from a friend. It turns freely. It has been out of his car for a while so I want to clean it.
A/C flush is about $13.00 a can.
Should I clean the lines with A/C flush or can I use something like mineral spirits or brake clean, both of which are a lot less money and the brake clean evaporates much quicker.
Also I want to clean the compressor out before putting it on the car. Any advice on procedure and what I should use.
I have not looked at the orofice/expansion valve to see if any debris got into the system.
I will also be flushing out the condensor and evaporator.
Can you clean out a relatively new accumulator?

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glen

My advice, if I were going to all the trouble you are to get the AC in tip top shape, would be to buy a NEW compressor, new dryer, and new orifice/expansion valve. I've been there, done that too many times on trying to get unkown quality used parts to make the AC work properly. I just recently got the AC going in my 3800 swap, with the aforementionded new parts advice, and I can literally freeze myself out of the cabin now if I wish.

quote Originally posted by LAMBO: My advice, if I were going to all the trouble you are to get the AC in tip top shape, would be to buy a NEW compressor, new dryer, and new orifice/expansion valve. I've been there, done that too many times on trying to get unkown quality used parts to make the AC work properly. I just recently got the AC going in my 3800 swap, with the aforementionded new parts advice, and I can literally freeze myself out of the cabin now if I wish.

do this and spend the $13. Otherwise you may end up contaminating the system or wasting refrigerant.

I have an 87GT with a 5 speed V6, and although the AC worked in the past it is no longer working now. The last time I tried to re-charge it with R134, I noticed some black substance coming from the high side line on the gauge set (I did not have the valve closed). I have to assume from that, and the fact that the system is just barely blowing cool air out the vents, that I will need to perform a complete overhaul. My question is one that I am certain has been asked before, but how much of the system really needs to be replaced?

I am pretty sure I should replace the compressor, as I have a pretty good suspicion that it is a DA6 unit, as the car was made in January of 87. But I have yet to go under the card and get a look to confirm. I am also pretty sure I should replace the accumulator and the orifice tube. Also, I am sure I need to replace any of the O-Rings in the system where the system is taken apart.

Should I replace the lines running under the car?

Should I replace the condensor? Can this be flushed without removing it?

Should I replace the evaporator? Can this be flushed without removing it?

When moving from a DA6 to an HR6 compressor, what things change or need to be modified, if any?

Last question - has anyone found a single source to obtain all the necessary parts? I recall seeing a good low cost source that carried all the parts (compressor, accumulator, variable orifice, etc.).

quote Originally posted by computer_engineer: I have an 87GT with a 5 speed V6, and although the AC worked in the past it is no longer working now. The last time I tried to re-charge it with R134, I noticed some black substance coming from the high side line on the gauge set (I did not have the valve closed). I have to assume from that, and the fact that the system is just barely blowing cool air out the vents, that I will need to perform a complete overhaul. My question is one that I am certain has been asked before, but how much of the system really needs to be replaced? I am pretty sure I should replace the compressor, as I have a pretty good suspicion that it is a DA6 unit, as the car was made in January of 87. But I have yet to go under the card and get a look to confirm. I am also pretty sure I should replace the accumulator and the orifice tube. Also, I am sure I need to replace any of the O-Rings in the system where the system is taken apart. Should I replace the lines running under the car? Should I replace the condensor? Can this be flushed without removing it? Should I replace the evaporator? Can this be flushed without removing it? When moving from a DA6 to an HR6 compressor, what things change or need to be modified, if any? Last question - has anyone found a single source to obtain all the necessary parts? I recall seeing a good low cost source that carried all the parts (compressor, accumulator, variable orifice, etc.).

I'm in the middle of getting my A/C running and can answer a few of your qustions. I ordered the accumlator, adjustable orfice and a seal set from rock auto. You will get those cheaper there, unless you have a cheap auto store around you. I have a few cars and the DA6 to the HR6 look exactly the same except the tag on the side. It has the same 3 plugs,(clutch and 2 on the back) The mounts are iddentical so I will assume they are the same. My car was a 5/1987 and it had a hr6, or it was replaced. It looked pretty new once I wiped it down, so I'm hoping for the best. I also bought 8 oz of oil for my system. I got the right kind, but the name escapes me, I want to say it was ester oil. It came from any autoparts store.

I have my system all reconnected, but need to vaccuum it out, check it, and charge it.

Here is where I am. I pulled out the compressor, condensor (very easy to get the condensor out. just 4 bolts and 2 lines and it slips out the bottom)and the lines. I am going to clean the lines super good since I have them out of the car and flush out the evaporator in the car. I am going to super clean the condensor since I have it out. The orifice/expansion valve is completely plugged up with grey gook. The compressor did not seize. It turns just fine now that it is out. It built up so much pressure as a result of the plugged up orifice tube that it was locking up. I will not reuse the compressor. It also blew out the o-rings where the lines bolt up.
The oil in the compressor and the condensor is a dark grey.
Does anybody know of an inline filter?

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glen

This what I did, basically built a combined filter and orifice tube:

This is the inline filter from keep-it-kool. I used part number A8201 for ½ inch tube.



This is the orifice tube that screws into the inline filter. Keep It Kool part number A8207.



This is the doc’s blocks fitting I used to install the filter in place of the original orifice tube assembly. Just cut to length



Here’s a picture of the completed assembly.

Big ver of pic

Installed:



Big ver of above pic

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Dave

www.ltlfrari.com

The orifice tube has a fine mesh on it. thats the only "filter" i am aware of.

It would be nice if there was something the size of a fuel filter that could hold a lot of gunk before it clogs up. I suspect that there is a sizeable amount of gunk in the condensor which I will do my best to flush out. I plan on letting mineral spirits sit in it overnight then cleaning that out with brake clean followed up by ac flush. I will do the same to the lines. I will start on this tomorrow. Getting the compressor, lines and condensor out today was enough.

One last thing to make sure you replace is the high/low
side schreader valves. This is just to make sure you don't
have a leak on something that costs approx $3 to replace.
Needs to be done before system is charged up and is
just good insurance. I found them at autozone.

Schrader valves are new and do not leak. I will take a look into the evaporator box and clean out the debris. Might as well I have all the rest of the ac system apart. Thanks.

Just a note about cleaning the condenser. It cannot be cleaned completely by spraying or pouring A/C flush or Brake Kleen in and then using air pressure to blow it and the gunk out. The reason? It has two sets of tubes. There is a "y" connector at the inlet of the condenser and also at the outlet. You will certainly get one set of tubing clean but the other more clogged tube will hold the junk and crud and will most likely be the cause of your next A/C failure. Your only recourse is to purchase a new condenser.

You should not have to remove the hard lines from under the car unless they are damaged or there is gunk stuck in there from years of sitting after an A/C failure. If your system was working ok and then failed, you should be fine with just flushing (using A/C flush fluid or Brake Kleen) and blowing it out thoroughly with compressed air. There will be a mess at the other end of the hose so have some rags handy...

If the A/C fails and you want to do a long term repair you should purchase these items:

New A/C compressor (or reman if you are brave)
New accumulator
New orifice tube
New O-rings
4 to 6 cans of Brake Kleen
New oil, PAG or Ester, your choice.
if your going to stick with r-12 then hopefully you can source some good clean used r-12 or NOS if someone has any.
134a retrofit kit if you need it. and some 134a.

The items that need flushing:
All hard lines, preferably with all connections disconnected. ie: each individual line by itself. This is a good time to replace all the o-rings.
The evaporator core. usually lots of oil collected in there so watch out for much yellowish gunk coming out. flush repeatedly until clear fluid is coming out.

Oil:
There is usually around 8 ounces of oil in the system. The compressor instructions normally tell you how much to put where. A little goes into the compressor (if it does not already have some in it. refer to the documentation) A little in the condenser, A little in the evaporator, etc. The total should add up to around 8 oz.

Then start installing all your new and or reman goodies.

Once everything is together, use a A/C service vacuum pump and pump the system down for a minimum of 30 minutes. I usually pump it down for 90 minutes or more. Depending on your altitude you should see around 30" vacuum at sea level decreasing by 1" per 1000' above sea level. It should show that vacuum on the gauge within the first 5 to 10 minutes and then hold it while the vacuum is pumping. After you have run the vacuum for at least 30 minutes, close the valves on your gauge set and let the system sit for at least 6 to 12 hours. You should still have the same pressure showing on the gauge to indicate that there are no leaks.
If you do have a loss in pressure, there is a leak somewhere and be mindful that it could also be your gauge set line connections. Finding the leak is a whole nuther thing. If you do not have leaks then you are ready to fill the system with your favorite refrigerant. (if using 134a, you can plan on using approximately 80% of the amount of r-12 normally used)

One more note: if changing from r-12 to 134a then the compressor cycling switch needs to be adjusted to open at around 20-21psi (134a) compared to approx 27psi (r-12).

Disclaimer: This is just a quick and dirty laundry list and may not be accurate. For those that really know how to do this please post corrections. I did not list freon charging amounts in oz's because I do not remember them off hand.


Charlie

[This message has been edited by cptsnoopy (edited 08-14-2009).]

Charlie is correct. I would add that if you absolutely plan on reusing the condensor that you put inline filters such as ltlfrari suggested or you will explode another compressor. That gray goop you describe is a sure sign of compressor failure and even if it only ran 2 minutes before completely quitting, there is compressor debris all through the system. These failures do not happen in an instant. After 20 plus years, your best bet is to replace the condensor too! If you are converting to R134, spend the extra dollars and get the variable orifice tube. If you don't see days in excess of 105* ambient air temps, the standard duty variable tube works fine. Most places carry it for around 19.00 and it's worth every penny. The extreme duty tube is for temps in excess of 105* and they run 34.00 and up. The Evap can be flushed in car. As said above, put a vacuum pump on it when it's all back together to pull all the moisture out of the system. It will also show you if you have any leaks before you waste freon.

I used a synthetic freon in the last one I did. It does not get as cold as the cheaper stuff but only by a couple degrees. What I did notice about the synthetic is that it seems to keep a more consistent cold temp. It pretty much blows 38 - 40 degree air regardless of driving in town or down the interstate where the other - cheaper freon - seems to creep up to 42 - 44 in town but will freeze you out on the interstate @ 36*. Some of this is probably attributable to the complete system(s), one is a V5 compressor and the other is a HR6.

According to the previous owner who donated the car to a Vo tech school 5 years ago, the A/C never worked. So there is old gunk throughout the system. That is why I took the lines off.

quote Originally posted by groble: According to the previous owner who donated the car to a Vo tech school 5 years ago, the A/C never worked. So there is old gunk throughout the system. That is why I took the lines off.

Prolly a good idea.

Charlie

Based on a friend here on PFF. I flushed each component separately with 100% denatured alcohol. It was ~$15/gallon. I used two gallons, but I wasted a bunch by not doing it right at first. Probably could get away with 1 gallon. Biggest pain was figuring a way to flush with the components in place. Very awkward, but with a couple sections of vinyl tubing I was able to do it.


The system works like a champ now.

Denatured alcohol. Great Idea. Low cost and absorbs water. I will get some today and try over the next couple of days.
Can you use it in the compressor to clean it out? I am talking about a compressor I got from a friend from a known good car.

Basic diagnosis for AC that I use at the dealership when I have to (i'm not the AC guy,just every now and then)

Pull the orifice tube and look at it,if there is any trash in it at all replace the orifice and drier-flush all lines and recharge.
If there is any metal whatsoever (even a few shavings) replace the compressor,orifice,drier-flush all lines and recharge.

And someone mentioned Ester oil,I believe the correct oil for R134a is PAG oil.
The directions that come with the new compressor don't always have the right oil or capacity listed-use the spec's for your car adjusted for the change in Freon type.

And ALWAYS do a visual inspection of all components and diagnosis before testing.
I preach this to my friends,and pulled a bonehead myself this week.
Been planning to repair my AC,and even got an R12 recharge machine a friend gave me from his shop.
I ordered a new accumulator and orifice in preperation to open the system and have to flush etc...

Finally pop the hood and look at the accumulator and notice a retrofit sticker and fittings!
Recycled,pulled/held a vacuum and recharged it and it works perfectly.
So now i've got a spare accumulator and orifice-though i'll more than likely buy an upgraded condensor and just redo the whole system (maybe use a different compressor).
It's cold but not as cold as I beleive it should be,haven't put a temp probe on it yet.

Can you clean and back flush the accumulator with denatured alcohol?

quote Originally posted by groble: Can you clean and back flush the accumulator with denatured alcohol?

No. Just replace it. A new one at AutoZone is ~$12

In case you don't know it you can borrow a AC system vacuum pump and guage set from some AutoZones. It allows you to do the job right and you don't have to be out the expense of buying your own.

quote Originally posted by DefEddie: And someone mentioned Ester oil,I believe the correct oil for R134a is PAG oil.

Edit: I did a quick search and found this: Ester is for both r-12 and 134a (normally found in retrofit kits from what I see) PAG is what GM has been using since they started putting 134a in production vehicles. (for our cars, PAG with a viscosity of ISO 150 would be used) So, it would be a good idea to look carefully at the New or reman compressor documentation to see what type and how much oil is in the compressor when shipped. Then if you want to keep it simple just buy that oil and go from there.


Charlie


Edit again to add this:

[This message has been edited by cptsnoopy (edited 08-15-2009).]

I have a vacuum pump and a low side gauge so I am good there. I found the accumulator at Advance for $12.99 so I will get one. Will probably put it together next week depending on hurricane and tropical storm. I live in Ft. Lauderdale area

Figured I would throw this in to add to the above PAG info as I could be incorrect about PAG being R134a specific.
Ford also uses PAG exclusively,at our dealership at least.
It is Ford branded and in the workshop manuals lists it as the required oil.

You guy's are driving me nuts with these 12$ accumulator's.
I had to special order mine,and it was 19.95 before my discount (I moonlight as a PSM for autozone).
I think I remember seeing a 13.99 option but just went with the one that said OE replacement.

And don't try to clean the accumulator-just replace it,same with the orifice.