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Guys, I have rebuild many motors, transmissions, and even setup a few rear ends in my time--but I have no experience with air conditioning.
I recently rebuilt my 2001 Camaro SS, which went well, thanks in part to advice from all of you.
Going back together, I let my low-pressure AC line sing up against my water pump pulley, and 5000 miles later it has sawed a hole in the line... a little oil has leaked out, and of course, no AC.
Watching online videos I understand that I will need to buy a vacuum unit and some gauges.
I have already bought AC Pro's recharging kit (when I thought it might just be low on Freon after 18 years).
The AC worked great until I messed this up.
Can I just replace the hose, vacuum it, and charge it with Freon?
What would you recommend as minimal steps as I have to be here anyway?
What brand of vacuum unit and gauges are you all having good luck with?
What about that oil? Is that a deal? Do I need to add some? Where?
Your car calls for 1.5 lbs r134a, two 12 oz cans is exactly 1.5 lbs.
Buy two 12 oz cans of straight 134, no additives and NO oil. If you buy some with oil you'll over charge the system with oil and it won't cool well. If you get the kind with dye in it there will also be some oil in there. If you want dye add a tiny amount or add dye to the oil and put that in the system. I wouldn't add more than 2 oz's total of oil or dye or a mix of the two. .5 oz of dye total should be more than enough for the entire system.
You can pour the oil down the hose or in the dryer. Does not matter where you add the oil. In an a/c system oil flows with the freon so it will distribute itself. R134a requires PAG oil, DO NOT use mineral oil. All data did not have the spec but I believe your car uses PAG 150. GM's back then and in the 90's used 150. New cars use PAG 46.
I rent vacuum pumps and gauges from autozone. Purchase a can tap while you're there so you'll have a way to hook the can to the gauges.
Drain the remaining freon however you plan to do it whether you poke the valve and let it out or take the car and have the freon recovered.
BUY 2 new schrader valves for the high and low side service ports. I can't remember what the F body high side schrader looks like but it may be a screw in assembly, it's extremely common on GM's to use those, you can unscrew them with pliers, (important) brace the line if you have this style when breaking the fitting loose out of the line. If you don't have that style then it will be two valve cores exactly like what goes in a tire. Most likely the high side is a fitting and the low side is just a core in the drier. Nothing more frustrating that finishing up charging a system and a schrader gets stuck open and blows out all your freon and oil all over the place. You'll need a valve core tool to change the valves. When you put the high side fitting it, snug is good. It doesn't seal on how tight you get it so cranking on it does not help anything. Plus if you're hard on it you'll break or kink your line, or marr it up to where you can't get the high side hose on.
** Leave the system open the shortest period of time possible. If you have a decent leak to where there is no pressure/freon left at all replace the drier. Add approx 1.5 oz's pag oil to the system for oil lost through the change of the dryer and loss of oil from the leak.
Once the system is empty swap the hose and install new o rings too.
Make sure the gauge valves are shut (clock wise shut, counter clock wise opens them). Hook up the gauges to the fittings on the car and hook up the vacuum pump to the yellow hose on the gauge set. Open the valves. Vacuum the system for 10-30 minutes.
Longer the better here, but really it depends on if any moisture or cleaner was introduced to the system. If you still had some freon/pressure left in the system then moisture didn't enter. And if your quick-ish with the work and it's not super humid 10 minutes will do, but no harm in going longer if you can. Shoot for 30 min if you have the time. Even more if you feel like it, but shouldn't need to do so.
Close off the gauges and disconnect the vacuum pump.
Screw your can tap to the gauge set input line (yellow) and tap the can by wrapping the tap around the can and squeezing, or if you bought the kind that goes on the top of the can screw it on and tighten the screw clock wise to puncture the top of the can, then unscrew it to back the pin out of the hole it made in the can so that freon can flow. Lightly crack the yellow hose loose up at the gauges to purge air from the line. Just real quick and tighten it back. Basically like hitting the purge button on nitrous for a second. Then empty both 12 oz cans into the system. It will have a hard time pulling the last bit of the last can into the system so run the car while charging the system or just while doing the last can. If it doesn't seem to empty the first can you can run the car while putting in the first can, the a/c needs to be on for this and once you have enough freon in the compressor will come on and click off then on and click off as more freon gets in the clicking on and off will lessen.
Make sure the fans run and if they both work everything should be good to go.
Last edited by 00pooterSS; 03-19-2019 at 07:15 PM.
What incredibly thorough and detailed advice--I so appreciate all the time you spent writing it--and I will have the good sense to take every bit of it seriously. It happens that I have already bought the new lines, a new drier, a new filter, and the wrong oil (I'll fix that). I will go after Schrader valves tomorrow. I hope that, down the road, others like me will benefit from your advice. Again thank you.
What incredibly thorough and detailed advice--I so appreciate all the time you spent writing it--and I will have the good sense to take every bit of it seriously. It happens that I have already bought the new lines, a new drier, a new filter, and the wrong oil (I'll fix that). I will go after Schrader valves tomorrow. I hope that, down the road, others like me will benefit from your advice. Again thank you.
No problem at all, let us know if you have further questions.
Try to find the oil spec for sure before following what I wrote. I'm pretty sure it's 150 but not 100% certain since I can't pull the info on alldata
@00pooterSS, I figure I owe you description of how things turned out:
My Camaro is cooling at 44 degrees, according to my analog thermometer (almost great, no?)
One of the Schrader valves came new with the dryer
The high pressure one I could not get out (it is larger than normal, and I couldn't (over the weekend) find anyone that carried a tool large enough to get over it. I tried needle nose pliers, all that... nothing worked, so I left it.
I bought a vacuum pump and gauge set--which were worth every penny--worked great--held a 30" vacuum steady for over an hour, etc.
I bought two cans of R134a with no additives exactly as you suggested,
I bought an AC Pro mix of PAG 150 oil (you were right about that, too), that came with dye mixed in it.
I tried to put 2 oz of this down the yellow gauge line--that did not go well--might have got 1.5 oz in, but the line filled up... I refilled the yellow gauge line with oil for each of the two cans of R134a.
I am concerned that I may not have got enough oil in the system. I probably should have dumped it down some line before I sealed it up, but was afraid the vacuum step would pull it out, and I didn't want to crack anything open after the vacuuming. Thoughts on how I could have done this better?
Now you have to teach me how to tag people on here lol.
As for the oil. Next time just dump it in the drier itself or in the a/c line on the car while you have everything open. No biggie. If you got an ounce in you are close enough to where you need to be unless you've had leaks in the past that let oil out that you didn't replace. If you get real concerned you can get a dye injector and put some oil in it and add a little that way. 44 degrees is absolute ****. Here and there you'll see some systems get into the upper 30's but it's not very common. And newer cars are getting worse, a lot wont get below 50.
The high side line fitting... it should screw out of the line.. it should look like this guy below. I have the special socket for it, but at $50 it's not worth buying to change just one. I changed them for almost 20 years with channel locks..
That's the common GM high side port. It's been quite a long time since I have done a/c work on a 4th gen F body, so I can't remember if it uses that style.
Take a pic of yours if you would and I can tell you what to do with it so that you know in the future.
The high side port is larger than the low side schrader, and those larger schraders are a pain in the ***. I have take screw drivers before and cut the tips off to where I have just the round shaft left and slotted the shaft with a cut off wheel and then grinded down the outside of the shaft till it fit down in there.. to make my own tool. I now have the right one and it's a general a/c service port tool. But I honestly prefer the one I made by far. The one I bought is small and there isn't much to grip and those larger ones can be pretty tight sometimes.
However, if you have the one like I posted above, it should have a rubber ball in it, and the updated style I go back with is a small scrader same as in the low side. So I may be wrong on that one I posted.
As for tagging you, I just highlighting your info and copied it and pasted it into the post.
My Schrader high-pressure Schrader housing is welded right into the high-pressure line and not detachable as an assembly. I like the custom tool idea. And I'll know better next time on the oil. Thanks.
03-18-2019, 10:18 AM
Air Conditioning Hose Replacement Advice 
