ok so a couple years ago i bought an ac compressor and the refill stuff the problem i had was the refill fitting wouldnt fit my high low port, so i went to all the auto part places trying the different adapter fittings to try to get the r134 into the system and i couldnt find one,i gave up and removed all the ac components well now i have a 2 month old son and i dont want him to overheat so my question is has anyone come across this and if so how did you fix it, thanks

 

Since ALL cars have the same AC fittings, .... you have the right adapter fittings.

There are 2 ports on the systems in our cars. (some other cars have more or less) There is a 3rd on the type of GM system we have, that the low pressure cutoff switch is attached to. One of them is on a line, and is smaller than the rest; that's the liquid line, which carries cooled (condensed... fresh from the condenser) compressed liquefied refrigerant to the evaporator (which is where it evaporates, thereby lower its temperature MASSIVELY and allowing it to absorb heat, which we perceive as "cooling"). This port is smaller than the others. You don't really need it for anything 99% of the time; put a cap on it with a new O-ring inside it to seal securely, and leave it alone and don't worry about "fittings" for it.

There are 2 ports on the accumulator/dryer. They are identical. The one that ends up facing toward the blower motor should have the low-pressure cutoff switch on it. You will put the switch there with a new O-ring and leave it alone.

The one facing toward the front is the low-pressure service port. That's the only one you really need to be concerned about. You will have at least one adapter fitting that fits it; if not, go buy one. That is where you'll hook your vacuum pump and your charging hose.

Remove all lines and other smaller parts that are still in the car. Throw away the accum/dryer and get a new one. Get all new O-rings for every fitting, and new seal things for where the line assy hooks to the compressor. If the compressor was NEW before you did whatever all else to it before, dump the oil out of it. Remove the orifice tube and throw it away.

Remove the old "barrier hose" sections from the metal lines. You can cut the old crimped fittings off with a wizz wheel; just be SUPER CAREFUL not to damage the metal lines themselves.

Flush all the remaining parts out with NON-RESIDUE solvent of some sort; lacquer thinner, acetone, MEK, denatured alcohol, or {gasp!!!} AC flush. NOT mineral spirits, turpentine, brake parts cleaner, or ANY OTHER substance I did not list in the prior sentence. You can do this on the car with a small funnel and a piece of rubber hose. Blow it through with compressed air and a white towel over the opposite end to catch the fluid coming out. Repeat for each part until the solvent comes out CLEAN. CLEAN means, NO contamination of any kind: not oil, not dirt, not metal dust, not ... ANYTHING, other than CLEAN fluid.

Put new "barrier hose" onto the metal lines, in the same length as what you took off. Use AC hose clamps, not the POS things hanging in the radiator section at AZ: they are DIFFERENT, they are MUCH stronger, wider, more durable, and otherwise BETTER. Lube the new hose with fresh PAG oil to help it go onto the line pieces easier.

Get the red/orange Frod orifice tube. Its orifice size is MUCH better suited to a GM R-12 system with R-134A in it, than the GM tube's orifice is for the same mismatch. I've heard that the blue Frod tube also works well but have never tried it: I KNOW FOR SURE that the red/orange one does work GREAT though, so get that. Ask for like a 96 Crown Vic at the counter.

Reassemble the whole system. Pour about 3 oz of fresh new PAG oil from an unopened can into the suction port of the compressor (the one the larger line hooks up to), and about 2 oz into your new dryer. Tighten all the fittings snug BUT DO NOT "gorilla" them. Turn the compressor a few times by hand, making sure you turn the compressor and not just spin the clutch.

Install the LPCO switch. Put the ONE and ONLY adapter fitting you need onto the other port on the dryer.

Evacuate the system. Make sure it goes below 29" of vacuum (within 1" of deep space) and keep the pump on it for at least an hour. Shut the pump off and verify that it loses no more than 1" of vacuum sitting there for another half-hour (i.e. the gauge still reads at least 28" after 30 min.) If it doesn't hold vacuum it won't hold a charge either: if it leaks, fix it and re-evac. You can use nitrogen or even compressed air, and soapy bubbles (MUCH better leak detector than ANY other method I know of) on all the fittings and stuff, to locate leaks. Repeat until it holds vacuum.

Once that is successfully complete, put 2 cans of R-134A in it. Start the engine, turn the AC on, and put 2 more in. It'll be a little too much, but since R-134A rarely leaks out of the atmosphere and into the system, it's usually a good idea to start out with a bit too much, since that way it won't be undercharged starting the first time one molecule leaks OUT. The air coming out the vents with the engine at 2000 RPM for about 2 min. and the blower on High, should be around 35 - 40° cooler than ambient. If it is, you're ready to roll.

Mods, PLEEEEEEZE make this a sticky this time: I'm kinda tired of typing it every single year.

 

If I'm understanding your post, the reason you couldn't get the refill hose to connect to the system fittings is that R134a systems have different fittings than R12 systems.

I've had this link saved for a few centuries now - GM Retrofit procedures:

http://www.e38.org/pparish/gm-rp.htm

The information in the link might be dated but the section topics are still relevant. I deviate from the procedures some what because I can spend the additional time it takes to do these things (keep in mind that GM will always recommend a procedure that works but the bottom line is "time is money....")

Unless the compressor has blown its guts, AND the system has not been opened and exposed to air for any length of time, AND there is no unknown refrigerant or sealants introduced into the system, AND the system is not leaking, I don't bother with hose replacement or system flushing. IOW, I usually have to go through what has already been posted.

If I do flush I usually use an ester oil instead of PAG in clean system but either is fine. Otherwise, PAG is required if you're going to leave the mineral oil in the system. Make sure you use the correct viscosity PAG. PAG150 is what should be used in GM R4's.

Receiver/dryer and orifice tube replacement is mandatory in any retrofit as well.

If you recharge at home with those little grenade cans, keep in mind that the weight on the label includes the weight of the can. Last time I weighed an empty 12oz. can it weighed around 3.2oz so consider this when you calculate your R134a charge weight.

I don't do this on my own cars, but when you switch an R12 system over to R134a you should really install adapter fittings to the system. These fit over the existing R12 fittings. The reason for the adapter fittings is to ensure that whom ever has to work on the system in the future will know what refrigerant is in the system. Shops get really pissy when R134a and R12 get mixed in their recovery machines.

 

This is what I was looking for, thank you!

Just one question, how much PAG150 should I put in? Factory calls for 6 ounces of mineral oil. Does this hold true for PAG150 in this car?

nevermind I see you put that in, very helpful post. ordering parts now. thanks!

 

150 is too thick for our systems. They do better with the "medium" viscosity; 75 or 80 -ish.

Yes 6 oz is OK, maybe the upper end of the acceptable range. I usually use about 5, as detailed above.

Hoses usually leak at the crimped ends. If you have to go to all the trouble of "fixing" all that, might as well just change out the hose. Even more so, if you're going to all the trouble of repairing and replacing all the other 30-yr-old rotten and deteriorated stuff, it makes NO SENSE WHATSOEVER to leave old hose on the car. Any more than it would make sense to replace your radiator, heater core, and water pump; but leave the old hoses on THOSE parts. Penny-wise and pound-foolish. RENEW IT ALL to minimize the chance of .... ,, .... , .. ,,,,,. .... SURPRISES.

Remember ALWAYS: you're working on a 30-yr-old car. The condition it's in NOW, the things that have wore out NOW, the parts that have failed NOW, are MUCH DIFFERENT from the parts that would have failed and needed replacing 20 yrs ago. Much less "centuries" ago. Not to say that that's not a good read with good advice and all that; just, obsolete. Likewise, GM's procedures are for NEW cars at THE STORE, or close to it; NOT, cars that are a half-century old with a million miles on em. What you would recommend replacing as part of a "normal rebuild" at 10,000 miles when something breaks, is VERY DIFFERENT from what needs to be replaced after 300,000 miles and 30 yrs.

 

Thanks, I keep seeing PAG150 vs. GM stating ester oil. Now you say a thinner viscosity. I only see PAG, 46, 100 and 150 at the stores. Is there any other?

I have a new dryer, just ordered a FORD orifice tube as suggested. I was going to cut out the old tubing from the metal, clean them with lacquer thinner install new barrier hose and replace with proper clamps. I have new green o-ring kit and ordered the ones for the compressor as stated above as well.

I have the gauge kit with vacuum pump and I just services my 2005 Grand AM, works great! Now I am doing my 2000 minivan. The Firebird or Jeep is next.

All the help you guys give is awesome.

 

100 will work. Seems like different stores have different choices, depending maybe on the brand. Whatever they have as their "medium" should be in the right range.

Those compressor seal things are weird; there's a bunch of different thicknesses. Try to make sure you have enough of the right ones for your comp/lines combo before the moment of truth arrives. I often buy them as an "assortment" just so I can avoid ... surprises. I HATE getting those.

 

Great 100 it is.

I ordered them spec for the firebird compressor. Hope they are right but will remember your advice. Thanks again

 

cool thanks guys, im on to fighting with the transmission switch

 

So I go into AutoZone and Advance Auto. Bumbling morons had no idea what Barrier hose was let alone the clamps.

I found Barrier hose on eBay but cannot find any clamps for AC hose aside from the standard heater hose kind or the crimp type, very expensive. So what type of clamps can I use and where can I get them please? I figured I need 1/2" id and 5/8" id for each hose. the 1/2" has a 1" OD and the 5/8" has a 1 3/32"

If not, then 80 bucks for a new factory hose assembly.

However, the AC has not worked in YEARS, say like 24 years. I tested the compressor and its fine. Have a new accumulator as well and the Ford valve as suggested. Will put PAG100 oil in it too. So with it being so long do I even need to cut out the old hose? or can I just try the original?

 

I think at this point I am I am going to just order a new hose assembly. Too much trouble otherwise.

I will go with PAG100 oil as well. Thanks for all the info gents!

 

Just an A/C update. I put in a new rubber/aluminum hose setup. I replaced all the seals and that filter tube with the ford red one. Put PAG100 in the accumulator and compressor, about 5 ounces total.

Well ran a leak test on it with a pump and dials, held for 1 hour, no issues. So I filled it up with 2 12 ounce cans. She was working great. Sadly, between the accumulator and the evap core the seal gave away and let out all the new r134a. Not sure why this happened. So I will wait until next year being summer is winding down and the firebird goes to bed on Oct. 1st anyway

2 x 22 bucks gone... ARRRRGGGGHHH

 

Last update, I got it working!!! I matched the o-ring from the accumulator to the evap core the first time. It blew out on my. So I put a thicker one on and PERFECTO!!! I HAVE A/C in a 27 year old car that has NOT had A/C since 1994. (never bothered to fix it)

AMAZING!!!!

I replaced the factory tubing, all new O-rings, Ford Orifice, and PAG100 oil. Put 2 ounces in compressor and 3 in accumulator. I did run a compression test with the first o-ring and it passed, so I was upset it failed once I charged the system the first time. Once fix I ran a pressure test again with a pump and dials, let it sit for 3 hours. No leaks. Charged it up, working.

Thanks for all the help on this one fellas.

 

 

thanks, now if I can just figure out my stupid fog light hook up....