Charging A/C System

[SVXMAN2001]

I've done some researching before posting however am still a little confused about the charging process for a 92 SVX a/c system.

Background: I am replacing every component within the a/c system (Compressor (rebuilt); lower pressure hose (muffler); High pressure hose from compressor to condensor; condensor; high pressure line with trinary switch from condensor to drier; new drier and new expansion valve. I will be flushing the high pressure line from the condensor to the evaporator and the evaporator itself (these are the only two parts I am reusing).

So my questions concerns are:

1) The manual states to initially charge through the high side (with engine OFF) while in liquid form? I am not all too familiar with this but my can of freon seems to be in liquid form? the only reason I bring this up is because once a can is used up on the high side, the manual states to finish charging on the low side with remaining freon in vapor form???

From what i've read a lot of systems charge only on the low side, why is this different on the svx?

2) I need to purchase a vacuum pump, does anyone have any suggestions?

3) I am sticking with r12 and need to use compatible oil for the compressor and fittings throughout the system. What type of oil should i be using?

4) Anyone have a set of r12 gauges they would be willing to lend or sell?

4) Has anyone installed an in-line a/c filter? I did a little research on the internet and some of these require cutting of the OEM piping...not too fond of this idea.

Thanks in advance for any help/suggestions, thanks Chris

[msvx95]

I am very interested in someone knowledgable on this subject too. I disconnected one of the lines to the a/c compressor while removing my intake and I believe I have to recharge the system now.

[dcarrb]

I don't know if it matters—probably not—but be mindful that a reman compressor may be intended for an r134 system.

dcb

[SVXMAN2001]

Funny enough, after searching the forum's I went with your suggestion and get a reman from 1airconditioning. The instructions indicate that the oil used is compatible with both r12 and R134a systems. That and the reman is specifically for a 92 model. So I think i am set on that front.

[Conn SVX]

Y are you staying with the old r12. iT WILL BE HARDER TO GET EVERY YEAR. bOTH MINE HAVE BEEN CONVERTED AND THEY BOTH CAN FREEZE ME OUT OT THE CAR. sORRY SHIFT LOCK STUCK

[kwren]

I personally would evacuate the system, close the port and remove the vacuum pump, connect the hose to the high-side from the inverted refrigerant can, open the high side port and charging port on the can to get as much as possible of the liquid in the system, when this is accomplished, close the "high side valve and close the valve on the can, start the engine and set climate control to allow the air condition compressor to come on, then connect the hose to the low side and slowly put the rest of the liquid refrigerant in the system... as instructed with the charging kit. This is of course with the proper charge size of refrigerant.

You are to be commended for attempting this project and I'll bet you can pull it off!!

Keith

[kwren]

Originally Posted by Conn SVX

Y are you staying with the old r12. iT WILL BE HARDER TO GET EVERY YEAR. bOTH MINE HAVE BEEN CONVERTED AND THEY BOTH CAN FREEZE ME OUT OT THE CAR. sORRY SHIFT LOCK STUCK

r-12 IS FINE! wITH WHAT YOU ARE DOING, YOU SHOULD BE GOOD FOR YEARS!

kEITH

[alia176]

Couple of things for you to consider:

- be sure to put the correct amount of R12 based on the low/high manifold press readings, ambient temp readings (2" in front of condenser) AND based on your elevation.

- I like R12 and you can find them all day on Craigslist. I should've stayed with R12 on my '92 but when I converted five years ago, I didn't know any better.

good luck.

[Green1995SVX]

I've actually got a little stockpile of R12 in case mine ever needs to be recharged. Still on the original charge, and working great!

[1986nate]

Originally Posted by Green1995SVX

I've actually got a little stockpile of R12 in case mine ever needs to be recharged. Still on the original charge, and working great!

Usually can find people selling old tanks on craigslist as well. Smart thinking on your part, Mike.
I just found out tonight, even R134a is going to begin starting to be fazed out. The new stuff they will be using is R138. A little over twice as expensive as R134a, probably won't cool as well as R134a (which doesn't cool near as well as R12), but on the upside, on the systems equipped with it from the factory, should take far less than the R134a systems need. Full charge in most vehicles should be between 1/2 and 1 pound.

Still wish it was easier and cheaper to get R12.

[svxfiles]

Originally Posted by 1986nate

Usually can find people selling old tanks on craigslist as well. Smart thinking on your part, Mike.
I just found out tonight, even R134a is going to begin starting to be fazed out. The new stuff they will be using is R138. A little over twice as expensive as R134a, probably won't cool as well as R134a (which doesn't cool near as well as R12), but on the upside, on the systems equipped with it from the factory, should take far less than the R134a systems need. Full charge in most vehicles should be between 1/2 and 1 pound.Still wish it was easier and cheaper to get R12.

Easier and cheaper...
Than...

[SVXMAN2001]

The more research I do on the charging procedures the more confused I become. The first link more or less described the charging procedures as per the SVX Factory Manuals. The second link however repeatedly warns against initial charge through the high side as this will cause severe injury or death!!! I am inclined to follow the factory manual however still very leary given the article.

The second article indicates that the high side will be forcing refrigerant into the can and thus causing forced freon to enter the can. I am thinking this article may be referring to charging on the high side while the engine is ON. The factory manual repeatedly insists the engine to be OFF.

While the engine is off the system is pulling a vacuum while the engine is on the system would forcing freon out if charging on the high side? Any thoughts?


http://www.aircondition.com/tech/que...ing-Procedures

http://www.polarbearinc.com/Trouble11_charging.htm

[SVX_MY_BABY]

I switched my PT Cruiser to 12a from R134 by just topping off the system from the low pressure port. Nothing as involved as what you are doing. Blows nice and cold. 12a is ozone friendly and you can buy it with or without oil in the can or buy the oil separately.

[Conn SVX]

You mixed it? I thought that was a NO NO

[SVX_MY_BABY]

Glad you started this thread. Can you advise what the correct low and high side pressures are for the 92 SVX?

My A/C in my 92 has been intermittent to non working. It was converted to R134 may years ago so I figured the system was just a little low on gas and thought I'd top it off with a 6 oz can of 12a which is completely compatible with both R134 and R12.

When I hooked up the pressure gauge to the low side port it read 80 when the engine was off and pulled between 50 and 35 when the engine was running and the compressor cut in.

I also heard a hiss coming from the area of the compressor for about 30 - 60 seconds after the engine was switched off. Is this normal?