Too cold to finish repair-how best to leave a/c system for winter?
 

I've been scrambling to get my a/c done while the tempurature is still above 70, but I can't make it. I have a part that's arriving via UPS, and by that time it will be in the 60's.

Should I close up the system as is or should I pull a vacuum and leave it at that?

good question, I think I am going to end up in the same situation.

I am not sure what the condition of your system is now but, if you pull it into a vacuum it will equalize pulling in outside air. The best bet would be to complete the freon side of the system, pull a vacuum and leak check then put at least a holding charge on the system for the winter. It still may leak out if the seals have dried out. If you can weigh the charge in there is no reason why you can't charge it while the outside temp is 60.

anybody know how much refrigerant an SC A/C with the big york compressor should take? Can you still "weigh the charge" using small cans, just by using the right amount of cans and being close enough?

What should I use a high side reading?

The printout I am using indicates psi at 115-200 for temps of 70-80.

There is no right amount if you are using R134a. You just have to add a few ounces at a time while checking your vent temps. If you so no more increase then stop adding.

I bought this scale so I would know exactly how much R134 I added.

Rightonscale.com

Only cost $29.99

There are pressure/temperature charts that should get you there. I'm looking, are you still using R-12 or did you change over?

I guess I'm confused. I havent done 134-a. There is no weigh in value for the charge? You say your supply vent temperture is the determining factor? If so you will reach this at less than a full charge at 60 degree ambient. You would then need to top the charge off when you begin using the system in higher temps. Im not sure it will be alot different at 70 vs 60.

I was waiting on a/c flush (that's what holding me up)but I may go ahead and use laquer thinner followed by brake cleaner. I just didn't want to deal with skin and breathing protection and also having to protect the vehicle's plastic and metal parts.

It's supposed to hit 80 tomorrow then it plunges to the 50's-60's.

Do you know if it's ok to use laquer thinner in the hoses?

I'm using R-12, is there a spec amount for that? I have a haynes book that has some specs for our cars, but not the total refrigerant quantity, if I remember correctly.

My Bentley manual indicates 47 oz. for 87-89 Carreras. I also have a sticker on the egine that has the amount. http://forums.pelicanparts.com/uploa...1128118404.jpg

I'm note sure if that is correct amount for your model year though.

According to my yellow sticker:


Charge Level 42,3 OZ

r12 (ccL2f2)

cAUTION
Refrigerant lines of air-conditioning under pressure

thank you guys.

What is inside the coil that you want to flush out? I have never used either of those to flush a system. My experience is not in auto ac but in commercial havc but even with a compressor failure you could use filter dryers to clean a system. If it is really fouled or you just don't know the condition you can try these if someone else can confirm that its been done.

I was changing the o-rings to HNBR (green) as the R134a conversion was a half-assed job done by the shop. I noticed debris in the tube.

My evaporator looks awful as you can see.

http://forums.pelicanparts.com/uploa...1128122776.jpg




Anyone know what is used as a replacement for the strips of tar that covers the expansion valve? I tore mine up pretty good.


http://forums.pelicanparts.com/uploa...1128122813.jpg

Prestite Tape:

http://www.acsource.com/index.asp?P...TS&Category=230

An HVAC supply house will have it. It is affectionately known as "Monkey S---" They may have a suggestion for cleaning inside that coil as well. The exterior i know they will have cleaner for. CalClean is one brand you can use. Even comes in aerosol cans.

Good Luck

Flushing is required if a component such as a compressor or receiver/drier has failed and released debris into the system. It is also helpful in removing mineral oil (which impedes heat transfer in the condensers and evaporator) from the system when converting to R-134a. See below link for aerosol flush for interiors and exteriors of condensers and evaporators; dry interior passageways with compressed air after using flush.

http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Co de=AR4201

See below for R-134a and ester oil compatible o-ring lubricant and sealant; also works well as a sealant to make more reliable seals in flare fittings (coat the metal to metal sealing surfaces).

http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Co de=RT201B

KobaltBlau:
If your car has the original type dryer, there is a viewing glass on it behind a plastic cap. In the viewing glass there is a white ball. When the white ball floats on top of liquid your system is full. The ball goes from sitting to floating rather quickly, so be careful. Also let the system run after you stop putting in R12 to allow it to balance out. The dryer is located in the left front wheel well.
When you are putting the R12 in, put the can of R12 in a bucket of warm water, this helps turn the liquid r12 to a gas