AC compressor seized, Black Death!!

dannym · Post by **dannym** » 18 Mar 2009, 05:56

Hello everyone-

I've been looking around and don't see much on AC repairs.
The compressor seized up the AC isn't working. Guess I got a case of the "Black Death".

Needless to say there's no power steering now either.

I'm going to flush the system out & get a junkyard compressor.
My questions are.
How hard is it to get the expansion valve out?
Does the compressor have an oil sump? Usually you put oil in it, turn it around a few times & put it in. Is this correct?

And what I really need to know is how much oil does the system take? How much oil goes in the compressor?

Any other tips or tricks that can make it an easier job will be appreciated.

Thanks

Danny

Post by **billofdurham** » 18 Mar 2009, 16:33

Tough luck on the compressor.

Is it still using R12 or has it been converted to R134A?

Expansion valve removal:

240 expansion valve.pdf: (397.66 KiB) Downloaded 546 times

I shall look up the rest when I know what refrigerant is, or was, in there.

Bill.

dannym · Post by **dannym** » 19 Mar 2009, 05:26

It was converted to 134A.

Are there any free online manuals anywhere?

OK, you have to remove the whole evaporator assembly. Doesn't seem to hard though. Can you rate the difficulty of this & how long it takes?

I guess that makes it easier to flush it out!

Danny

Post by **billofdurham** » 19 Mar 2009, 13:36

R134A makes it a little easier, I think.

Online manuals? I thought that was me.

Seriously, I don't know of any that cover cars from this era.

My book shows 2 hours 15 for the evaporator but that is as part of a 'composite job' so I don't know if it includes taking out the back axle, sorry glove box, or if it is just for the evaporator. It doesn't look too hard a job, just fiddly and uncomfortable:

240 evaporator1.pdf: (631.89 KiB) Downloaded 321 times

240 evaporator2.pdf: (643.61 KiB) Downloaded 363 times

240 evaporator3.pdf: (1.16 MiB) Downloaded 304 times

The '88 240 should be fitted with a Kiki or Zexel compressor. If you are buying one from a junkyard be sure to empty out any oil that is in it and replace it with 0.125 litres (4.23 fluid ounces) of ester oil, P/N 1394828-6. The drain plug is at the rear of the compressor and the filler plug is near the top. A syringe is recommended for filling.

Bill.

dannym · Post by **dannym** » 20 Mar 2009, 06:04

Thanks for the info.

Is there a procedure for flushing the system without removing the evaporator?

Danny

Post by **billofdurham** » 20 Mar 2009, 12:46

You can flush the system without taking any parts off but you need access to either a flush machine or a recovery/recycle machine. Failing that you can buy a flush gun but it needs a compressor and air line.

There is at least one aerosol on the market that claims to flush the system but the small print states that it also requires an air line.

Bill.

dannym · Post by **dannym** » 20 Mar 2009, 13:36

I have air so that's good.

So the expansion valve is open to allow the flush to pass through the evaporator?

I know in my MB you have to remove the guts from the expansion valve to get it to flush through.

Danny

Post by **billofdurham** » 21 Mar 2009, 13:26

After further research I have found that the expansion valve should be removed and flushed separately. I also found this which relates to all cars:

OUR PROCEDURES FOR FLUSHING AUTO A/C SYSTEM
We use a plastic bottle to put the solvent into the system then we blow it through with a rubber tip blow gun. We only flush through heat exchangers and free flowing hoses. We use dry air or nitrogen at about 125 PSI to blow through the system. We flush in a reverse direction to refrigerant flow first to dislodge any material caught inside. After we flush the system to our satisfaction, we pop the components dry in both directions.

1. Pop the components dry, means that: We blow the major part of the solvent through the component and catch it in a capture tank or shop rags.
2. We hold the blow gun tight at one end of the component.
3. We hold our finger over the other end until it builds up pressure.
4. We release our finger letting it blow off pressure.
5. We repeat until there is no sign of solvent coming out.
6. When we flush we pull a long vacuum.

This is an extract from http://www.e38.org/pparish/flushing.htm

I learn something new every day. My wife says I should have started learning earlier.

Bill.

dannym · Post by **dannym** » 21 Mar 2009, 14:03

That makes a lot more sense though it makes it more difficult.

I was thinking about what you said about adding & draining oil from the compressor. can you tell which port from these pictures is the drain & fill? I don't see anything on top.
actually looking at the Haynes manual it only lists a drain plug.

The Haynes manual says;

If a new compressor is being installed follow the directions with the compressor regarding the draining of excess oil prior to installation.

Of course I don't have these instructions.
I opened both ports #1 & #2 on the back and only got 2 or 3 drops out. I put oil in each one and spun the compressor around and it all drained out from the same port??

I guess my question is how do I make sure I got all the old oil out & have the proper amount of new oil in it.

It's weird because the Haynes manual lists oil capacity for replaced components:
receiver/dryer 0.35oz
evaporator 1.4oz
condenser 0.70oz
Hose assemblies 0.35oz
With a total refrigerant capacity of 45.8oz for 1990 & earlier.
That means the compressor holds 43oz of oil!!

I'm thinking if the compressor really drains out I should have got a lot more oil out of it???

Danny

Post by **billofdurham** » 21 Mar 2009, 16:42

That looks like the Kiki compressor, especially if the name on the label in pic #2 is Seltec. That is the US trade name.

My book shows the fill point on the top:

240 AC compressor.pdf: (513.22 KiB) Downloaded 395 times

I think your calculations are a little out. The amount of oil for that compressor is 4.23 fluid ounces. You are quoting the amount of refrigerant, not oil, at 45.8oz.

Bill.