I recently had the AC converted to 134A. AC worked great for 3 days after I got the car back. Now I only get warm air out the vent.. I can hear a clicking noise coming for the engine bay and I think its the AC compressor but I am not sure.
I used the gauge from a 134A refill can (like the ones sold at autozone ) and noticed that the pressure goes from 20 PSI to 45 PSI with every click I hear.
I have a read post about the compressor not coming on because of the air gap. But there was not mention of a clicking sound in these posts.
If the clicks are at kind of the same interval, maybe 2-4 seconds apart, they're probably the sound of the A/C compressor clutch engaging/disengaging. The compressor doesn't run 100% of the time. The clutch is cycled by the pressure switches in the A/C system. If the system is partially charged, it won't cool efficiently and the clutch will cycle much more often than normal (if the charge is very low the clutch will not engage at all). I don't know exactly what "normal" is (never timed it) but it seems like maybe 10 seconds on, 3-4 seconds off, or something like that. If the clicks are the clutch, then the conversion may have added a small leak, causing the system to be under charged (unless they undercharged it to begin with after the conversion). I think it's undercharged because the pressure you're reading will be higher when the clutch is off, lower when it's on. And the low end for a normally charged, normally operating system is 35-40 psi. High end is around 60 psi or so. Try charging it till the lower pressure reading is 35-40 psi. The clicks should be further apart and the system should cool. If it stops cooling or the pressure readings are low again in a couple of days, the system has a leak.
Here is the latest... I didn't add any addition Freon to the system because the clicking went away and I didn't recheck the system with the gauge on the refill bottle. My assumption is that I do have a leak and the remaining Freon escaped. I'll be dropping the fiero off at the shop on Friday.
I got the car back from the shop. Turns out the compressor is leaking. Per my mechanic, I need to replace the compressor. Sucks... I kinda wish I would hunted down some R12 cans vs. a conversion of 134A.
What are the parts needed? Compressor Orifice tube Drier? ???? ???
What would be the average cost to get this done? I was quoted $500 for everything. reasonable?
Anyone know if there is some additive I can add to try to fix the leak ?
You said you had the A/C converted to R134; was this done by a shop? I'd talk to whoever did it (unless you did and you don't already talk to yourself). Did the system leak before the conversion? If not, I think a compressor leak is quite a coincidence. But you could develop a leak elsewhere due to the conversion. This conversion requires that all of the O-rings at all of the hose connections be changed because the oils used with R134 attacks the old ones. It can also attack older rubber hoses, but any replaced since the introduction of R134 should be compatible with both old and new. I've heard that seals in R12 compressors can fail when converted but I've done two conversions (both GM but not Fiero) and I did not have this happen - unless it took years because one compressor eventually did fail but it took three years. Anyway, I'd verify the location of the leak if possible. When I bought my 88 GT two years ago it had already been converted but didn't work until I found and a leak where the o-rings hadn't been changed. Then I changed all of them and no problem since.
Regarding prices, I haven't had a shop quote this but for a complete conversion, or replacement of the parts you list, I believe $500 may be reasonable. But If it was properly converted before you shouldn't need to do all that. When I converted those systems I mentioned, I replaced the accumulator and all seals, flushed the rest of the system, added the proper oil to the compressor and charged the system.
I recently had my complete system replaced. It had been converted many years ago, but the compressor finally gave up. A complete kit is/was available on Ebay that contained a new compressor, accumulator and orifice tube for $202. Though I didn't buy the kit, had I done so, adding labor and refrigerant would have brought the cost up to about $500. Given that you're in California, I'd say that's a very good price.
In the information pages with my compressor, it suggested that the compressor mounting brackets be loosened at the engine and the compressor brackets be tightened to the compressor first, then tighten the bolts at the engine. The stated reason is that our compressors don't have dowel pins to locate the 3 case sections to one another. Trying to force it to fit to the brackets can cause the sections to twist slightly, breaking the seals.
Something else that was used on my system's seals at every point where it was opened was a product called Nylog Blue. It's a seal coating. I believe it was RWDPLZ that told me about it. When I went to an AC supply house, they had extremely high recommendations for the product to prevent leaks. A pretty common product used by residential and commercial AC techs, but he didn't understand why it wasn't well known to the automotive repair industry. It pretty much guarantees that you won't have O-ring leaks when using this product and it's compatible with all refrigerants.
It's only about $7 per bottle and will last forever. For more information on Nylog Blue, check it out on YouTube. https://youtu.be/vAULfI8-Wwk
I just ordered some NyLog Blue. I thinking of doing as much work myself to keep cost down.
On a scale of 1-5 , 5 being most difficult . How hard would it be to do the work?
Here is the parts list I have so far:
1. Compressor Autozone seems to have the lowest price at $210 2. OE replacement Single Orifice Tube RockAuto $3 3. Four Seasons 26735 O-Ring kit RockAuto $5 4. Universal AC Receiver Drier / Accumulator RD6070C RockAuto $12 (Needed?) 5. Four Seasons Mineral Oil 32 Oz 59000 Rockauto $9 (Correct one?)
Anything else needed?
One more question.... What would happen if you don't adjust the Clutch Cycling Switch from 25 PSI for R12 to 21 PSI for R134A?
How do I go about confirming the leak? What are steps? What O rings do I need? Where can I get them?
Depending on the severity of the leak, if you put in some R134 (gotta do that in any case) and you're in quiet surroundings, you might even be able to hear it (I could on my last one, but it was a pretty fast leak). Other than that, you can get R134 that has a UV dye in it, so you can use a UV light to see it. There are also detectors that are electronic "sniffers" that can detect it at the point of the leak. You might also be able to find it with soapy water, but I haven't actually tried that.
O-rings are pretty readily available from the usual sources, local auto parts or online stores. Seems the R134-compatible HBNR ones are usually green or blue (the old r12 ones are black.) I bought a 24-piece kit, which had more than necessary but covered everything.
I am in the process of the same repair. Make sure you budget for flushing the system. Mine was really gunned up. If I just replaced parts I am sure the orifice would have plugged immediately.
How did your mechanic determine that you had a compressor leak? After an R134 conversion on my Formula (by a shop), mine leaked, too. And it showed symptoms of a compressor leak. It turned out to be the sealing washers on the back of the compressor. They put in the wrong ones. Once I replaced those with the correct ones (and lubed them up with Nylog), the system sealed up fine.
How did your mechanic determine that you had a compressor leak? After an R134 conversion on my Formula (by a shop), mine leaked, too. And it showed symptoms of a compressor leak. It turned out to be the sealing washers on the back of the compressor. They put in the wrong ones. Once I replaced those with the correct ones (and lubed them up with Nylog), the system sealed up fine.
They didn't say, other that its a 30 + year old compressor and things are bound to break. He only stated that he traced the leak to the front of the compressor. I'll most like be buying some 134A with dye in it to confirm.
If you have access to a "sniffer" (leak detector), I would check it myself. I have a sniffer, and it indicated a leak at the back, and an occasional leak at the front of my compressor. When I replaced the sealing washers, I had zero confidence that my leak was fixed... until it held a vacuum for a week. I know it's a pain to get in there with a sniffer, but it could save you some money.
If you have access to a "sniffer" (leak detector), I would check it myself. I have a sniffer, and it indicated a leak at the back, and an occasional leak at the front of my compressor. When I replaced the sealing washers, I had zero confidence that my leak was fixed... until it held a vacuum for a week. I know it's a pain to get in there with a sniffer, but it could save you some money.
I am not sure if I can justify the cost for a one time use.
I'm not sure mineral oil is correct for r134a. My Autozone compressor said PAG oil. Wait until you have your compressor to see what its literature tells you. Autozone also sells the correct accumulator, not a universal fit.
Expansion rates for r12 and r134a are different thus the difference in cycle switch pressure settings. Most folks say to use 80% of system capacity which is aboit 32 oz. Information I found in a manufacturers conversuin site specified 90% which is 36 oz for the Fiero system. My installer only did 80%. Didnt cool as well so I added a little more. Great improvement.
OldGuyInGT - Thank you for the info on the O-rings.
Formula Owner - That's not bad at all on the price of the sniffer. I saw $200 plus.
fierofool - Thanks for the heads up on the accumulator at Autozone.
Would you guys say this is something that a one step above novice mechanic can do at home? I have done the oil changes, brake jobs, replaced starters and alternators. But nothing very major.
DO NOT use mineral oil. That is for R12 only. Since there is a chance that some residual Mineral Oil will remain in your system, even after flush, use Ester Oil. It is compatible with R134a, and also with Mineral Oil residue.
This is a project that you can do- just follow the steps correctly. Use some of the Ester Oil on each O-ring as you install, O-rings tear easily when tightened- the oil helps. Use the Oil that has Dye in it. Put a couple of ounces in the compressor ( after draining any oil in the compressor), 2 OZ in the new accumulator ( new accumulator is required), and 2 OZ in the condenser. Afer installing the compressor, and hooking up the hoses, spin the inner part of the clutch ( the part connected to the guts of the compressor) a couple of times, to distribute the oil. Don't want to start the compressor with liquid in it. You will have to pull a vacuum. Autozone may have a vacuum tool for rent, or you can buy one from Harbor Freight. Same with Gauges- best to use them for an install. All this investment won't go to waste- you'll be surprised how many friends you will acquire!
Originally posted by fierofool: Autozone also sells the correct accumulator, not a universal fit.
And if they don't, Rock Auto does. I bought one from RA as a spare. It was only around $30.
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Originally posted by str8maxn: Formula Owner - That's not bad at all on the price of the sniffer. I saw $200 plus.
I probably wouldn't have one if they were that expensive.
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Originally posted by str8maxn: Would you guys say this is something that a one step above novice mechanic can do at home? I have done the oil changes, brake jobs, replaced starters and alternators. But nothing very major.
If your skills are tapped out at doing an oil change... then, no. But if you can do brake jobs, you can do this.
darbysan's instructions are not wrong, but to start with, I wouldn't go to that extent. I would buy a sniffer, and verify the leaks myself. Inspect the lines coming into the backside of your compressor. The lines are connected to a bracket that gets bolted to the compressor. That bracket should not be all the way down against the body of the compressor. The correct sealing washers are thick enough that the bracket will be held away from the compressor body 1/8" or so. If the bracket is down against the compressor (like mine was), it has the wrong sealing washers. If that's the case, go buy some sealing washers, replace them (lubing the new ones with Nylog), and see if the system will hold a vacuum. I had a shop do the R134 conversion, so I don't know where those wrong sealing washers came from.
My installer is a friend of my daughter and son-in-law who works on cars as a sideline. He wasn't afraid to tackle my job though he'd never worked on a Fiero. He owns a Firebird. He said the compressor change 'whupped his butt'. First compressor was bad and he said he learned a little as to how to pull it again and put the second one in.
I want to confirm the leak first. Then I plan on reading up and youtubing how to's before I start the fix. Once I confirm the issue, I'll be getting all the needed parts together.
I am sure it's something I can handle, specially with great support like the one on this forum.
AC compressor pressure control switch. Is this the 2.5 iron duke? On the bottom of the compressor is a slip ring that holds in the pressure switch. It is about 3/4" in diameter and about 2.5" long. Remove the slip ring and pull the switch out. RA sells the proper replacement for R134a. R134a operates at a higher pressure and to get the correct cooling, this switch should be swapped out. I don't think it can be adjusted. The replacement will have a different spring loading.
O-rings: The worst O-rings to replace are on the pivot connection located in front of the rear axle on the driver's side. This connection enables the AC lines to remain attached when the cradle is rotated downward to access the engine. The bracket that holds the pivot has two bolts that are screwed into a couple of friction fit plugs. I can pretty much guarantee that one of those will destroy itself when you try to back the screw out. Good luck. I had a difficult time and my car was on a lift. The other O-rings that are problematic are the ones in the front that go to the condenser. They are probably pretty rusty and you will need to remove the air deflector under the radiator to get access to them.
My advice would be to open all the connections, and clean out all the tubes (I used brake cleaner and compressed air) and then put in the new O-rings (lubricated with medium viscosity PAG oil) and new orifice tube. Then put 3-4 ounces of PAG oil into the new dryer / accumulator and the other 3 ounces into the back of the compressor. Seal up the system and rotate the compressor by hand to move the oil around. Pull a vacuum on the system and if it holds for an hour or so, you're good to charge it up. While the system is evacuated, hook up the first can and allow the vacuum to pull in as much as possible, then start the car, warm it up and turn the AC on the highest setting and it should pull in the rest of the R-134a. When the compressor stops cycling, you have a sufficient charge. IIRC, it should take about 32 ounces (80% of the original 40 ounces for R12.) If it doesn't hold a vacuum and the area is really quiet, you might be able to hear the hiss. The other option is to check all the connections to ensure you didn't miss one.
Unlike most cars that have all the connections up front under the hood, it may be hard to find a shop that has experience with our little cars or will take the time to find all the O-rings that need to be replaced.
Go to the Rock Auto site and look up the ac clutch pressure switch for your year and engine. It will list one for r12 and one for 134. On the original r12 switch there was an adjustable screw. Save yourself headaches and just get the 134 switch. They list the 'on and off' pressures in the info. There is a difference and even if you find a leak, change to the correct switch while the system is being serviced. Also, if you haven't changed the orifice tube, do it while the system is open. Have the system flushed, and then have the system professionally pulled to a vacuum.
Macarchie - Thank for the info. Does this apply to the 2.8?
The 2.5L has the V-5 compressor. The easy way to tell is to look at the accumulator and see if there is a high pressure switch on the driver side of the accumulator; if so then you have the DA-6 compressor. The basic procedure is the same. I don't know if the pressure control valve is interchangeable in the DA-6 compressor. The V-5 compressor has both the high pressure and low pressure switches on the back of the compressor (red and green).
Unfortunately, I am not able to post pictures on this site. Send me your email address in a p.m. and I can send you a pic of the compressor with the control valve removed.
