1980 240D AC questions [air conditioning] - PeachParts Mercedes-Benz Forum

JimmyL · #1 02-21-2007, 11:47 AM

Trying to make the title search friendly.....

Temps are rising and the time has come. Here is brief background, with questions to follow.
The Squash was hit in the front at some point, and the condenser was replaced. The AC lines to the condenser ARE NOT CONNECTED, so the system has been open to the atmosphere probably for a year or 2. All components are there. I have a new exp. valve and rec/dryer already [in boxes] and am going back with R12. I do plan on dis-assembling every connection point, replacing all o'rings and flushing out everything with a flush gun.
Questions:

1) What is the effect on the system having been opened to the atmosphere for a period of time. Does this promote rust or scale-type stuff? The AC system in Scar is sealed [small pressure release if I press Schrader valve] so I've been leaning towards using that condenser and some of the lines. What do yall think?

2) I have 3 used compressors. One on the car now, one on Scar, and one I removed from the wagon last year to install a reman [I think it was OK, and exp. valve was my issue]. None are seized. Is there any way to tell the condition of a compressor when it isn't plumbed into a working system? I figure folks will say to just spend a little over a hundred buck and buy a reman, but even $100 bucks adds up.

I can't wait to experience the acceleration of a 240D with the compressor running......

rrgrassi · #2 02-21-2007, 12:02 PM

Does the A/C system on SCAR work? Dirt and moisture are an A/C system's worst enemies. If the components from SCAR are interchangable, then I would use them first to avoid spending "just another 100". Those 100's tend to add up fast.

I do not know of a good compressor bench test.

BTW, what did you think of the tint pics?

JimmyL · #3 02-21-2007, 12:32 PM

Quote:

Originally Posted by rrgrassi

Does the A/C system on SCAR work? Dirt and moisture are an A/C system's worst enemies. If the components from SCAR are interchangable, then I would use them first to avoid spending "just another 100". Those 100's tend to add up fast.

I do not know of a good compressor bench test.

BTW, what did you think of the tint pics?

The AC system on Scar does not work, but it does at least hold some internal pressure, therefore it hasn't been open to the elements. I have been leaning towards using that condenser at least. I will flush the evap along with the other lines, replace rec/dryer and exp. valve, and the compressor is still up in the air.
Your tint pics looked great. I called that place, and uh, I don't think the sharpest pin in the cushion took my call. They wanted $199 to tint the wagon, and I never asked any more questions based on the person I was speaking with.....

I was hoping for a 2 car package deal in the $220-$250 range [to drive out that far] but at the conversation never got to that point....

rrgrassi · #4 02-21-2007, 05:06 PM

Quote:

Originally Posted by JimmyL

Your tint pics looked great. I called that place, and uh, I don't think the sharpest pin in the cushion took my call. They wanted $199 to tint the wagon, and I never asked any more questions based on the person I was speaking with.....

I was hoping for a 2 car package deal in the $220-$250 range [to drive out that far] but at the conversation never got to that point....

Sorry to here that. That means you did not speak to Gerard. He is the owner.

Good luck on the A/C. A used compressor is always a mixed bag, unless you know the compressor's history. Scar holding pressure is a good thing. Was it converted to 134? If so, 134 is cheap enough to charge the system and see if the A/C works. Bad thing is the incompatable oils of 134 and R12 and the discharge into the atmosphere.

Diesel Giant · #5 02-21-2007, 07:54 PM

Maybe this will give you some help

http://dieselgiant.com/repairyourac.htm

JimmyL · #6 02-21-2007, 08:18 PM

Quote:

Originally Posted by Diesel Giant

Maybe this will give you some help

http://dieselgiant.com/repairyourac.htm

I understand the procedures in your link. My specific question was for information not contained in your pictorial.
I guess it doesn't hurt to get your link back out there, though....

#7 02-21-2007, 01:23 PM

Well I've been watching for a/c groundhog day here on the forum and here it is.

Yes, whenever you open the system even if it's going to be for a matter of hours, it's important to seal it up as best you can.

That said, I would definitely cobble it together first with used parts AFTER a thorough flushing of everything.

Good luck,

JimmyL · #8 02-21-2007, 02:48 PM

Quote:

Originally Posted by LarryBible

Well I've been watching for a/c groundhog day here on the forum and here it is.

I saw my shadow and crawled back into my hole..... At least it isn't a R-134A vs. R-12 question.....

Quote:

Originally Posted by LarryBible

That said, I would definitely cobble it together first with used parts AFTER a thorough flushing of everything.

Good luck,

Is there a way you know of to diagnose an AC compressor, or something to look at/try to pic the best candidate?

1981_300sd · #9 02-21-2007, 01:29 PM

I am in the same boat. What is the best way to flush the AC system after the refrigerant has been removed?

dannym · #10 02-21-2007, 02:47 PM

Remove the expansion valve and flush the chiller core from outside the car using clear poly tubing from Ace Hardware.
Use expansion valve to size tubing.

Disconnect compressor manifold and remove receiver/dryer.
Flush both lines through firewall from outside car with same poly tubing.

Flush condenser from under hood.

For loads and loads of information on AC repairs use SEARCH button.

Danny

#11 02-21-2007, 03:30 PM

I assume that you mean diagnosing OFF the car. The only thing I know would be to turn it by hand to see that it is smooth and put your thumb over the outlet while turning to see if it pulsates with pressure.

Flushing is best done with a flush gun, but many people simply use brake cleaner which is already in a pressurized can. Make SURE, SURE, SURE that you get ALL of the flushing agent out of the system whatever the agent might be.

Flush the compressor with refrigerant oil ONLY.

Good luck,