A/C dryer question

[divecop]

I own a 1970, GS 455 and the A/C has not been charged or operational since I purchased it a few months ago. I'm getting ready to get it working, but someone told me that if the system hasn't been charged for a long time that you need to replace the dryer. He said that with no freon in the system, the dryer could cause problems once you go to start up the system once it's charged and functioning. If so, does anyone know where I can get a new dryer!

Thanks,

Divecop

[guyopel]

Most Auto parts stores have what you need and you may have to convert sys. to R-134 ref.
HTH
John

[Rattus]

If the system has not been opened, you have a chance at making it operational. However, if it IS open, you're going to probably spend a lot of money making it work well. A receiver/dryer would be the minimum you should put in the system. When you go to the shop for a recharge, be sure to tell the tech that it was dry of refrigerant. There may be residual moisture in the system, and it may take hours to evacuate it to the point where the moisture is low enough. While you are at it, you may as well replace all the O-rings, which you can buy in a kit. If you are going to use TC-134A instead of R-12 (which is mucho expensivo, now), be sure to get the proper O-rings. If you do change to TC134A, you should flush the system before adding the proper oil to the compressor- R-12 oil and TC134A don't get along, chemically. You'll need to put the proper oil in the compressor. There will also be residual oil in the system which is normally carried over into the other components. Some will be in the dryer, some in the evaporator, and some in the condenser. It'll all have to be removed for a change to TC134A, and I'd recommend it in any event, as that is where most of the system's moisture will be- in that oil- it is hygroscopic and will absorb it out of the outside air if the system is open.

[GL03]

I'm addressing this on the stand point of available parts: A/C dryer is disposeable. You can say it's a maintenance item. There is a leak in A/C, replace the dryer. The dryer is required to be replaced if system is open for longer than 4 hours.

In the standpoint of an old car, where parts are scarce: When the system gets recharged,15 minutes minimum vacuum is part of service, to remove residual moisture. But, some technician, that may be more interested in taking your money may do only 5 minutes.

With no leaks present,I would vacuum for 30 minutes, with original dryer, fitted, if part is not available. If cooling is okay, but you would like better performance, than you can take your time to find the dryer. And replace it at a later time.