luvmy64

Ive put a 350 in my 89 RS, and i want to replace the seals in the air conditioner system with new ones while i have all that crap apart anyway. Does someone sell a kit to do that with? Also, i will be putting 134a back in it....do i need special o rings?

tom3

Did this to mine last fall. Advance auto parts has a kit with all you'll need, probably AutoZone has them too. Only problem I had was the only o-ring I didn't replace, on the high pressure switch on the back of the compressor. Works pretty good with the R134 too. I used PAG oil with a new dryer and exp. valve.

LnealZ28

Better stock up on 134a, it's being phased out too. I can't remember the exact date but it will be this year I think. I do refrigeration work and just bought a 30 pound cylinder for $312.00 wholesale! Yikes! And I gotta get at least one more cylinder to keep up the units I have running on it. I don't have any idea what the automotive apps will be using for refrigerant, but the alternatives for refrigeration stuff are, IMO really dumb. R404A is pretty popular in ref. apps but I don't think it would be suitable for auto stuff. Just some random thoughts and a heads up.

LnealZ28

Okay, I have been given bad information. Really bad. I have been educated and would like to clear up my statements above. R-134a WILL be a long term refrigerant and will continue to be used for many years. The chart I have in front of me shows it going beyond 2030 so I stand corrected.

ScrapMaker

I heard from a few mechanics just the other day that r134a is going to SKYROCKET in price in the coming months... for whatever reason.

they are stockpiling this stuff.

for reference, about a year ago a 12oz can was like 2 for $7... now its almost $8 for a single can... (at walmart)

phess11

I heard it is going up because the Patent is running out soon so the Patent holding company (don't know who it is) is making money now before the patent runs out.

phil

ScrapMaker

makes sense... so it's gonna go up big time... then as soon as everyone and their dog can make this stuff... it will become even crappier... cheaper, but crappier.

89_ho_rs

i am about to do the 134a retrofit kit. when i turn my ac on now. the ac compressor does not kick in. is that because i don't have oil or preasure in the compressor? when i do the retro fit kit will the compressor start to work or will i have to waste all of the stuff i just put in and buy a new compressor. i have an 89 camaro with the stock ac and now a 350 with a carb. thanks for any advice.

tom3

Usually the problem is low charge, but it would be a real good idea to do a pressure check before doing anything else. Could be an electrical problem. If the system is completely our of refrigerant you'd also need to pull a strong vacuum for a while to remove air and moisture, and should replace the drier/receiver and expansion valve, add new oil. When you hook up the can of refrigerant, the can pressure will make the compressor start. Good idea to charge with the can upside down, charging right side up charges with gas and the vaporization in the small can lowers the temp in the can and reduces pressure, makes it tougher to get it charged.

thirdgen88

One thing that hasn't been clarified in this thread yet that might be helpful to people looking for parts: our systems use an accumulator and orifice tube (as opposed to an expansion valve system).

tom3

Technically you're correct and no argument, but when you go to buy the part it's called an expansion valve as from Autozone:

A/C EXPANSION VALVE

FACTORY_AIR A/C EXPANSION VALVE for a 1989 CHEVROLET CAMARO
Unit Price: $1.99
Core Value*: $0.00
Part No.: 38623
Weight: 0.00 lbs.
Warranty: 1 YR

How about "orifice tube expansion valve?"

ScrapMaker

from auto zone:
new compressor $220
oriffice tube $1.99
accumulator/dryer $29.99
high-pressure switch $18.99
retro kit $45

btw, DON'T get the retro kit... unless you really need the valves

when you put a new compressor on, you need to put SEPARATE oil into the compressor and turn it a few times by hand to get it lubricated inside...

then you use regular 134a... WITHOUT the oil in the mixture... otherwise you'd have WAY too much in the system.

the retrofit kit I bought had 12oz of 134a, and 3oz of oil in EACH can... that's 9oz of oil in the compressor, which is too much to start with... you need like 6-7oz

so I swapped my mixed cans with a friend, and got some 12oz 134a cans... now it's blowing ice.

I just need to figure out if my radiator fan is supposed to ALWAYS be on with the AC, or just with something triggers it.... since someone said that the high pressure switch just turns off the compressor, not engage the fan.

tom3

Pretty sure on the 90 model, there are two pressure switches . One on the dryer controls the compressor, another on the high pressure line down by the frame controls the fans. They turn on at a higher pressure, say 200 psi or so, only. The earlier models, I think 88 and back, have a normally closed switch, after that it's a normally open that closes on high pressure. If you have the wrong switch the fans will come on with the AC but turn off with higher pressure. I'd double check your switch, this would have the compressor cutting out on the overpressure switch on the back of the compressor, not good for it. Again, not sure on the 90 model, may have changed a bit.

ScrapMaker

hrm, you say by the frame rail, not exactly sure what you mean... but I know for a fact that the low pressure switch, (on the dryer,) works, since I tested it before I put in any actual 134a.

the high-pressure switch (on the back of the compressor,) works because it shuts off the compressor when I kill the power to the fan and the pressure jumps up like crazy

are you saying that there's another pressure switch somewhere else that triggers the fan? if that's true, then most likely I will lose all the 134a pressure...

at least it's cheap, and not $60 a 12oz can.

does anyone know what pressure the high-pressure switch engages at, (on the back of the compressor?)

because if those are the only two pressure switches on the system, something else is f-d up...

I guess I need to know if the high-pressure switch on the compressor kicks in at like 200, or like 400...

firebirdjones

My 88 Iroc also has a switch on the high pressure line, it is the aluminum line that runs along the top of the frame on the passenger side. Very easy to spot once you know where to look. I retrofitted mine over to 134 about 2 months ago. Replaced all the o-rings in the entire system and removed each part to flush out the old oil and make sure everything was clean. I reassembled with new 0-rings. I then hooked up my vacuum pump and sucked it down for about 45 minutes and made sure it was drawing a good vacuum, charged it with a little oil and freon and it works perfectly. Very easy to do, just takes a little time. Larry.

ScrapMaker

Thanks, I'll look for that switch...

also, you know the only reason to put a vacuum on the system is to get all the old oil out, right? because once you open the system, all the r12/34a evaporates nearly instantly...

now it may have been better to do it your way, but what we did was allow the freon to escape... OH NOES! then we hooked up an air compessor and bursted air through the system until all the oil was done coming out...

then I replaced the compressor, oriffice tube, and accumulator/dryer.

sweetness... the only thing I am considering is adding a secondary A/C fan that's the same size as the condenser, so that I don't wear out my radiator fan too quick... although I bought a replacement radfan motor last week in anticipation... so I guess I have nothing to lose.

firebirdjones

Not to disagree but actually the vacuum pump on the system is assential to removing all of the moisture that has been introduced into the system. Once you open the system, it will have some moisture in it, because of that, I always replace the dryer, which I did, and the small orifice tube filter in the high pressure line, cheap insurance since it only cost a dollar. The vacuum pump is also assential in seeing if the system will hold vacuum before you shoot in a can of freon, that way you know you have a leak before you waste a can of freon.
I went one step further, mainly because I am very picky, I not only drained the system, but it is assential to remove all the old oil as it is not compatible with the new 134 freon. Rather than just blow it out, I also use brake clean, spray brake clean into the A-coil, condensor, all the hoses and lines, etc... one at a time, brake clean works good for this because it evaporates quickly and leaves no residue, I do each component one at a time, spraying brake clean and then blow out with compressed air, I then repeat again and again until the brake clean comes out spotless with no more oil residue, I then do this procedure in the other direction to make sure I get it very good,,,,,that way I am assured all the old oil is out. It is very hard to get every drop out since there are a lot of turns in the condensor and evaporator etc...where oil can sit in little cracks and such, (I told you I was picky), I then reassemble with all new o-rings, dryer, filter, and anything else that looks questionable, I then hook up the vacuum pump to remove any moisture but there is also a very key reason for the vacuum pump that a lot of people over look, You can see if the system will hold a vacuum before you even shoot any freon in it, that way you know if you have a leak before you waste a can of freon. All this is why I said it is time consuming, I am picky and like to do things very thoroughly, and the air blows cold enough to chill your beer after you are finished Larry.

ScrapMaker

you know what would be an excellent test?

since I have a BRAND NEW compressor, oriffice tube, and dryer... I wonder if I were ONLY change out the oriffice tube with the variable one... and compare the output temp of the AC... be some good info...

too bad my AC works good enough to where I wouldn't consider it now...

firebirdjones... correct me if I'm wrong, but doesn't the dryer/accumulator take all of the moisture out of the system and store it in the silicate? That's the whole point of it...

I can see why it's a good idea to do it your, (the right) way... but I also don't see a big difference... I highly doubt that if a LITTLE bit of old oil was left in the condenser or wherever, that it would noticably affect the output of the system...

the oriffice tube being variable... now that's a tough question... since I've never seen/heard of this before.

firebirdjones

Hello scrap maker, hows it going?
You are right, the accumulator/dryer is for pulling moisture out of the system. Any time the system has been opened to the atmosphere it is a good idea to replace it with a new one though, they are only in the 30-40 dollar range, cheap insurance and I find better A/C performance, plus it is nearly impossible to get the old oil out of those things.
I can tell you why I am such a finatic about removing all of the old oil. There are a couple of good A/C shops here, one in particular that does alot of vintage air installs in older muscle cars, and also alot of R134 retrofits. They retrofitted my old K5 blazer years ago. Something of intertest they told me was they dont guarantee there 134 retrofit work unless the customer buys all new A/C components because they had trouble removing all of the old oil out of the old parts. They told me that when the old oil mixes with the new stuff, generally the compressor will fail, not sure if that is true or just coincidense, but when they did my Blazer, I told them to just retrofit it and do the best they could to remove the old oil. It lasted a good while, about a year later the compressor blew apart. still not sure if that was oil related or not. Anyway, to make a long story short, I retrofit them myself now, I have done cars for other people, I have 3 of my own cars now that have all been retrofitted, My 79 pickup has been done for about 4 years now and still working perfectly, the Iroc was just done a couple months ago, and my Chevelle was done last year, they all work excellent. Because of what the A/C shops have told me and after what happened to my Blazer, I became very critical of removing the old oil, whether a little in the system does any harm or not I don't know, all I do know is I do everything I can to make sure I get it out as best as possible. Usually I remove all the components to have better access to them, takes more time but I can do a better job that way, especially the condensor, that thing has so many turns in it, I have found that with brake clean and compressed air I can get it pretty clean, then if I turn it upside down and do it again, I find more oil coming out, that junk seems to hide in there. Turning the condensor around at different angles gets the brake clean in the smaller areas in the turns etc....and I usually find more oil in there by doing this.
I know this all sounds excessive, I am just a finatic about working on my cars and I'm very picky. All of this may not be necessary and many have probably done less and gotten the same results, but this gives me peice of mind more than anything knowing I did as thorough of a job as I possibly could. It's just some of my experiences I thought I would share, maybe it will help someone. Later, Larry.

ScrapMaker

heh, all I did was blow air through the system until it stopped spewing out oil!

seems to work fine so far...

the only problem I have now, is that before we put the compressor on, I noticed it was REALLY hard to turn the compressor(clutch) by hand, and I just figured that's the way it is SUPPOSED to be..

now it turns out that it is putting too much load on the system and causing the belt system to bounce around and the tensioner is going crazy... and the pressure read fine on the compressor.

so now I have to buy another NEW compressor from autozone, and wait for it to come in, then when it does, bring in the old one and get my money back... otherwise I'd have to wait for 3 days and not drive my car... and I'd rather not waste time and labor by putting the old one back on in the meantime.

I think I'll go ahead and get one of those variable oriffice tubes while I'm at it... sounds like a good idea... are there any drawbacks to those puppies?