Hey all, I'm having issues with getting the A/C working on my 88 Formula. I've replaced the compressor twice now and the second one has failed the same way the first did. I retrofitted the system to R134A using the original compressor, which worked great for a while. Eventually, shaft seal failed on the original compressor, so I replaced it with a remanufactured unit. When I replaced the original compressor, I went through the system, flushed all the lines, flushed the condenser & evaporator, replaced all orings, replaced the drier, and orifice tube. I replaced the pressure sensors on the compressor and the pressure switch on the drier as well. Once everything was in, I vacuumed down the system, charged it with refrigerant, and everything was working great.

My Fiero is not my daily and sometimes will sit for a few weeks (months in the winter, weather depending). When I came back to the car after it had been sitting, it no longer had cold A/C. I went under the car and found that there was dye dripping down the compressor along the joints in the compressor case. There was so much dye you didn't even need the light to see the leak. So I assumed it was a bad reman and the compressor would need to be replaced again. This time, I ordered a new compressor kit (Four Seasons) with an new drier and orifice tube. Also replaced the pressure switches again. I vacuumed down the system, checked for leaks, etc. All good, charged the system, A/C was working great again. It worked awesome for about a month straight, no issues.

Last week, it rained a lot so the car was parked for 6 or 7 days. I jumped in the car yesterday to drive it to work and no A/C at all, compressor wasn't even kicking on. I checked all the connections with a refrigerant detector and U/V light, didn't find any leaks. Finally, I go to the compressor and the same thing; dye dripping down the side of the compressor along the joints of the compressor case!

I know that there is a potential that I just have bad luck and it could be a defective new unit, but it seems weird that 2 units in a row have now failed the same way. This is how I have been replacing the compressor, step by step:

1: evacuate remaining refrigerant from system
2: remove and replace drier & orifice tube (inspect orifice tube for debris when removed)
3: add oil to the compressor, if necessary (total oil in system 8 oz on PAG 150)
4: remove and replace compressor
5: vacuum system for 30-45 minutes (I use and electric vacuum pump)
6: mark manifold gauges and leave car for 15-30 minutes to verify there are no leaks in system
7: start engine, turn A/C to max
8: charge system with 24 oz of R134A (2 cans, additive free) through low side port

I have ordered a NOS Harrison HR6 compressor hoping that OEM may be better than aftermarket. I really don't want to blow up another compressor. It's weird to me that it seems to leak when the car sits vs when the car is actually driven. Am I doing something wrong? Does this issue sound familiar to anyone? Any advice or guidance appreciated.

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1988 Fiero Formula 2.8 intercooled turbo

Reman compressors are problematic if not outright junk. The new unit should solve the issue. I can't remember the r134 amount to add but don't go beyond 85% of R12. Are you using a good set of gauges when you add the 134? If not you should get or borrow a set.

Look at the hose assembly which goes into the back of the compressor.
I had the same thing happen and so I removed that assembly and there was a slight crack right where the fitting goes through that block.
You couldn`t see it just looking but when I moved one of the solid hose fittings the crack opened up.

quote Originally posted by steve308: Reman compressors are problematic if not outright junk. The new unit should solve the issue. I can't remember the r134 amount to add but don't go beyond 85% of R12. Are you using a good set of gauges when you add the 134? If not you should get or borrow a set.

I agree with you on the remans, which is why I thought it was a dud. First replacement was a reman, but the second replacement was a brand new unit from Four Seasons. I was using a set of harbor freight gauges, but came to the conclusion that they were junk (leaked at hose connections, seals would close up under vacuum). I replaced them with a good set of Mastercool brass gauges, which work WAY better. I've used them on my truck A/C as well and they work great. From what I've read, original R12 capacity would be 32 oz, so 24 would be 75%. I'm wondering if maybe I'm putting in too much oil?

The main problem with remanufactured parts is the people who are doing the work are just people looking for a paycheck and the training is limited to just replacing common parts that are the usual culprits on what ever part they are rebuilding. This means if there is another issue with the part it does not get corrected because the person does not know what to look for to identify any potential issues that may soon occur.

At this point I'm pretty sure the reman's are just repainted junkyard compressors.

quote Originally posted by RWDPLZ: At this point I'm pretty sure the reman's are just repainted junkyard compressors.

This actually makes too much sense

From my A/C work on cars the cause of a failed compressor can be:
1. A defective reman unit. Very likely
2. Debris in the system/ clogged condenser. Common
3. A severe overcharge of the system. Possible
4. Failing to put in a new orifice tube and a new accumulator. A mistake
Be sure to check high and low side line pressures after the install by referring to the temp vs pressure R-134A chart. I would always recommend using a new A/C compressor.
When recharging use Ester oil then put A/C setting on max cool and also occasionally rev engine while recharging. I additonally use a thermometer at the vent outlets. if you measure around 40*F your there.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

On your comment " I'm wondering if maybe I'm putting in too much oil?" Compressors are shipped with oil in it. Did you drain and measure it or did you just add oil to the system? If you didn't drain and measure before adding that would be the issue.

quote Originally posted by Dennis LaGrua: From my A/C work on cars the cause of a failed compressor can be: 1. A defective reman unit. Very likely 2. Debris in the system/ clogged condenser. Common 3. A severe overcharge of the system. Possible 4. Failing to put in a new orifice tube and a new accumulator. A mistake Be sure to check high and low side line pressures after the install by referring to the temp vs pressure R-134A chart. I would always recommend using a new A/C compressor. When recharging use Ester oil then put A/C setting on max cool and also occasionally rev engine while recharging. I additonally use a thermometer at the vent outlets. if you measure around 40*F your there.

1. The compressor has been replaced twice now. First was a reman, so probably a dud. The second (see pictures posted above) was a new Four Seasons aftermarket compressor. Both failed the same way.
2. When I replaced the original compressor, debris was present in the orifice tube filter. I fully disassembled the ac system. Both the evaporator and condenser were removed from the vehicle and flushed out. All lines were flushed individually as well. No debris has been found in the screen since the flush.
3. When charging the system, I use 2 cans of r134a with no leak sealer or other additives. This is 24oz of refrigerant which is about 75% of the original R12 charge, so it shouldn't be overcharged.
4. I replace the orifice tube and drier every time I recharge the system. I have been using a standard orifice tube. Maybe a variable orifice tube would work better.

I have been using 8 oz of PAG oil in the system. I know ester oil was the original spec and that ester and PAG don't mix, but seeing as I fully cleared the system, I figured there would be no issues with oil mixing and hurting the system further.

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1988 Fiero Formula 2.8 intercooled turbo

quote Originally posted by CharginPegasus88: So the reman came with an unknown quantity of shipping oil in it. I drained it, then put 4 oz in the compressor, 4 oz in the drier. The new compressor came with 3 oz of oil in it. I drained 1.5 oz from the old compressor and 1.5 oz from the drier. So I installed the compressor with the prepacked oil. It seems like a lot of oil gets caught in the condenser with these cars. When I flushed the system, it seems like a lot of oil was trapped there.

Flush remaining in the system can hurt a compressor by dampening the lubrication factor. Also PAG oil is recommended for new systems only not retrofits and that is why I use only Ester 150 oil. An amount of old 525 mineral oil remaining may be hampering the effectiveness of the PAG oil. PAG and mineral oil do not mix. Ester and mineral oil do. Did you fully evacuate the system to 29in/hg before charging? .Also check your R-134a cans and make make sure that they do not contain a oil R-134a mix. When you attach the charging hoses before charging do you turn the refrigerent on and bleed the hoses of air before charging. Those are the only items that I can think of


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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 07-26-2021).]

1) Fiero uses a GM HR6 compressor that has a crappy design (pressed case halves). If you have had 2 leaking mid compressor check for misalignment on the mounts. Any twisting forces as you do your final tightening of the mounts can twist the cases and cause leaks. Also, prying on the case halves to tighten belts can cause leaks.
2) I show a 40oz. charge for '88's. 32 oz would be 80%, then temperature test and add to full charge. 24 oz is grossly undercharged.
3) Evacuating the system should be to 29 inches of vacuum for NO LESS than 30 minutes
4) Check voltage to compressor clutch. With lights/blower/etc on you should have NO LESS than 12V at the clutch. Lower voltage will cause the clutch to slip and overheat the front seal


Temperature Test:
Car at idle, max AC, doors open, let run for 5 min to equalize
Check temperature at evaporator. Evaporator inlet (after the orifice tube) and outlet temperatures should be equal (+/- 5 degrees). DO NOT base this on duct temp as duct temperatures will actually rise slightly as you reach full charge. An undercharged orifice tube system WILL NOT move oil and you will destroy the compressor relatively quickly.
Check inlet/outlet at condenser - you should typically have about a 30 degree drop (give or take 10 degrees)
Check ambient air temp to duct - your temp drop should be close to the condenser temp drop.

Based on the fact both compressors cooled and then didn't, I would be most inclined to look harder at #1 & #4 above.

BTW...I work for 4Seasons and did AC training for technicians for many years. Most compressors (new and reman) get killed by junk left in the system, or by installation issues caused by misinformation. If you could only see the crap that comes out of "defective" compressors when we get them back.....

Bunch of older posts recommend 25oz. I did 32 in mine and had issues with the high pressure kicking off the system under load and it freezing over. I changed to 25oz and things run much better.