I'm swapping out my A/C compressor on my Stock V6 1987 Fiero GT Fastback and need to know what the Freon Capacity is along with which oil and viscosity to use to lube the system.
Also bear in mind that my system as been converted to R134A.

its going to be evact and so forth so the system will be bone dry.

Thanks

87GT2M6

Anyone???????

Been awhile but if I remember correctly, I used PAG 36 - 6 to 8 ounces - 3/4 in the comp and 3/4 in the accumulator and it took about 2 and half cans of R134 - but your gauges will tell you when you have the correct amount of R134. I'm sure others will chime in - Don't take my word for it.

Original specs for the Fiero were 2.5lbs of R-12, and 8 oz of mineral oil. Typically in an R-134A conversion, you use 80% of the R-12 charge, which would be 2.0lbs, still 8oz oil, but ester oil, which is compatible with both refrigerant types. PAG oil could used if you're 100% sure the system is completely clean and dry, but best not to risk it when doing a retrofit.

Thanks guys, pluses for both.

Did you flush the whole system? Or only compressor and accumulator being replaced? If not then you will have some oil so I would not fill to full empty specs. Vacuum will only take out Freon and not oil. Just in case 2lbs is 32oz or about a little less than three 12oz cans.

quote Originally posted by katatak: ... your gauges will tell you when you have the correct amount of R134.

No. You cannot determine the correct refrigerant charge using pressure alone. The only way to know for sure is to evacuate the system and recharge by weight. I know from previous research that for the '88 Fiero the correct refrigerant charge is 42 40 ounces of R-12, or ~34 ~32 ounces (~80% of 42 40 ounces) of R-134a, but I can't confirm the proper amount for previous years.


Edit: to correct system capacity.

[This message has been edited by Marvin McInnis (edited 02-24-2012).]

quote Originally posted by Alex4mula: Did you flush the whole system? Or only compressor and accumulator being replaced? If not then you will have some oil so I would not fill to full empty specs. Vacuum will only take out Freon and not oil. Just in case 2lbs is 32oz or about a little less than three 12oz cans.

Alex the compressor is used R12 but will be vacuumed and the dryer is new and the orifice tube is new. The system will be flushed and vacuumed so should be dry with no fluids.

does this change any of your suggestions? Thanks.

[This message has been edited by 87GT2M6 (edited 02-21-2012).]

The red and white switches do come out, the center just leave in there. Your white one is broken. More info here:

https://www.fiero.nl/forum/Forum2/HTML/117640.html

quote Originally posted by 87GT2M6: Alex the compressor is used R12 but will be vacuumed and the dryer is new and the orifice tube is new. The system will be flushed and vacuumed so should be dry with no fluids. does this change any of your suggestions? Thanks.

If you are flushing the system including evaporator and condenser then new specs capacities should be fine.

make sure to get a new Orfis tube filter as well if your old compressor quit it most likely got crap in the system.
do not put it in backwards! and also when chainging the psi. switches on the compressor remember that the new one has pressure in it and once you undo the snap ring the plug may fly out at you so keep a finger on it.
D.

Thank you and pluses for everyone whom I haven't given a plus to already.

I'm installing it on Saturday and I'll post the results soon after.

High-pressure relief valve, it vents when it reaches some ridiculously high pressure, should never need it if the high-pressure cutout switch is working and there are no problems with the system.

quote Originally posted by Marvin McInnis: No. You cannot determine the correct refrigerant charge using pressure alone. The only way to know for sure is to evacuate the system and recharge by weight. I know from previous research that for the '88 Fiero the correct refrigerant charge is 42 ounces of R-12, or ~34 ounces (~80% of 42 ounces) of R-134a, but I can't confirm the proper amount for previous years.

That must be a 4cyl, 87-88 4cyl do have to be charged by weight. On the DA6/HR6 compressors I charge by pressure.
And the correct charge for R-12 is 40oz (per the 88 service manual) and for all years.

quote Originally posted by whodeanie: make sure to get a new Orfis tube filter as well if your old compressor quit it most likely got crap in the system. do not put it in backwards! and also when chainging the psi. switches on the compressor remember that the new one has pressure in it and once you undo the snap ring the plug may fly out at you so keep a finger on it. D.

I don't see how a compressor off the car has any pressure in it.


Yes you have to swap the switches (red and white)
use 8oz ester oil as it is compatible with both, you will NEVER be able to flush the whole Fiero system, impossible by design. Only flush hoses, if you try to flush the condenser or evapator, you will mess them up forever.
Don't use PAG oil unless EVERYTHING is brand new.

Make sure you get a new orifice tube and dryer too.

------------------
"DRIVE IT LIKE A FIERO"
'84 Fiero, engine to be determined
'87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
^^^^ Now in the Construction Zone^^^^
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I purchased a rebuilt 4 Seasons compressor, It was pressurized from the factory and had instructions to release the pressure before doing any work on it. I loosened the bolt holding the cap on the manifold ports a few turns , then lifted the cap a smigie with a flat blade screw driver. After the 'poof' was gone I installed my two switches in the rear.

Only one I have ever seen this way.

-Joe

quote Originally posted by sardonyx247: That must be a 4cyl, 87-88 4cyl do have to be charged by weight. On the DA6/HR6 compressors I charge by pressure. And the correct charge for R-12 is 40oz (per the 88 service manual) and for all years.

You are correct that 40 ounces is the proper charge per the '88 GM/Helm Factory Service Manual. I have edited my earlier post to reflect that.

It is still incorrect that you can properly charge a system by pressure alone. For example, you can't tell by pressure alone whether the accumulator contains 90% vapor/10% liquid or 10% vapor/90% liquid. Once you have both liquid and vapor phases present in a refrigeration system (i.e. once the system reaches saturation), the pressures remain relatively constant at any given ambient temperature until you approach 100% liquid.

In some cases it is possible to charge an A/C system using pressure, temperature, and superheat/subcooling tables, but I've never seen such data published for any GM car.

[This message has been edited by Marvin McInnis (edited 02-24-2012).]

quote Originally posted by Marvin McInnis: No. You cannot determine the correct refrigerant charge using pressure alone. The only way to know for sure is to evacuate the system and recharge by weight. I know from previous research that for the '88 Fiero the correct refrigerant charge is 42 40 ounces of R-12, or ~34 ~32 ounces (~80% of 42 40 ounces) of R-134a, but I can't confirm the proper amount for previous years. Edit: to correct system capacity.

Maybe so but we've been charging by using gauge readings for years and we get em ice cold. My own Fiero is so cold in fact that it will blow you out of there on 90* days but it does use the GTP V7 compressor. I would not be afraid to charge according to gauge readings. Charging by weight is better but the gauges get you close enough to have your system blow ice cold.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "

I'd like to thank everyone who's participated in this thread, so with that said Thank You.

Here's whats happening so far:

I was at the a/c shop buying the dryer, orifice tube, freon etc. and I had the compressor tested. The shop owner had a guy test the compressor but the guy instead of putting it on the machine to test it tried to turn it by hand and when he could not said it was

stuck and no good, he put it down and left. The owner of the shop tried the same thing the other guy did but when he could not turn it he took it to the back and put in a little oil and hooked it up to whatever machine they have in the back and it worked.
he said it was a little noisy and would replace some parts it needed for $35.00 and that after that it would be like a new compressor.

I was not able to install it today as I thought because they did not have the dryer in stock so now I have to wait till next Saturday.

He did mention that I should use PAG oil instead of Ester oil because the entire system is going to be cleaned out and completely dry of any oils. I mentioned what you guys said here but he insisted that if the system is cleaned and the dryer and orifice tubes are new plus the compressor being bone dry "until the test" in which he used PAG oil that I should continue with that type of oil, 4 oz at the compressor and 3 at the entry point for lack of remembering the part he said up front.

Not remembering the part name is not an issue since I'm having a pro A/C friend doing the job even though he's never done a fiero before I'm sure its close to or the same as other cars.

Any comments and further suggestions are welcome.

quote Originally posted by 87GT2M6: He did mention that I should use PAG oil instead of Ester oil ...

I know that ester oil has better compatibility with R-12, but the GM service bulletin on R-134a conversions states that only PAG oil (of the correct viscosity) should be used in systems using GM/Harrison compressors.

quote Originally posted by RWDPLZ: The red and white switches do come out, the center just leave in there. Your white one is broken. More info here: https://www.fiero.nl/forum/Forum2/HTML/117640.html

You can buy new switches at most auto parts stores. I got some at Advance Auto.

quote Originally posted by Marvin McInnis: I know that ester oil has better compatibility with R-12, but the GM service bulletin on R-134a conversions states that only PAG oil (of the correct viscosity) should be used in systems using GM/Harrison compressors.

It is the mineral oil that PAG is not compatible with, everything I have ever read, including A/C training says the two mixed can turn to varnish. I would like to read that service bullentin if you have a link.


As I said above,
You will NEVER be able to flush the whole Fiero system, impossible by design. Only flush hoses, if you try to flush the condenser or evapator, you will mess them up forever.

To go into further detail, the condensor has parallel lines running through it, if you try to flush it, the flush will go to the path of least resistance, only go through one side and get flush caught in the other line wich will just eat any further oil you put in the system, impossible by design to flush. The evapator has a reservoir in the bottom of it that will hold old oil and flush if you try to flush it, impossible by design to flush.
So unless you replaced the condenser and evapator with new when swaping over to 134A, there WILL be some mineral oil left in the system. If someone tried to flush either of the two you have to throw it out and get new.


EDIT to add: if you go look at the condesor up front (in front of the radiator) you will see the lines split into 2 lines as they go in, then back from 2 lines on the outlet. Thus the parrallel lines I was talking about. Proof you can see with your own eyes.

[This message has been edited by sardonyx247 (edited 02-26-2012).]

quote Originally posted by sardonyx247: It is the mineral oil that PAG is not compatible with, everything I have ever read, including A/C training says the two mixed can turn to varnish.

Mineral oil is insoluble in R-134a, and both the EPA and GM state that residual mineral oil in an R-12 system properly converted to R-134a will migrate harmlessly to the low points of the system and remain there.

quote I would like to read that service bullentin if you have a link.

Previously posted on PFF, ACDelco TSB 05D-J-114:

"There are no Ester lubricants approved by ACDelco for retrofitting R-12 systems or for use in R134a systems."

[This message has been edited by Marvin McInnis (edited 05-13-2012).]

quote Originally posted by Marvin McInnis: From ACDelco TSB 05D-J-114:

Very interesting read, thanks for sharing. Also interesting:

quote RETROFITS As long as there is an adequate supply of R-12 refrigerant or until economic situations warrant, General Motors and ACDelco do not recommend retrofitting an R-12 vehicle to R-134a. If retrofitting is being performed, please refer to the ACDelco Technician’s Retrofit Guide on CD to verify that the particular vehicle has been approved for retrofit and established procedures are followed. To obtain a copy, contact your ACDelco Regional Sales Office. Incorrect retrofitting will not provide your customer with adequate air conditioning performance.

quote REFRIGERANT LUBRICANTS The only refrigerant lubricants approved by ACDelco are: R-12 Systems • Mineral oil – ACDelco P/N 15-117 (GM P/N 12301108) - 525 viscosity universal oil for all Harrison/Delphi manufactured compressors. • Mineral oil – ACDelco P/N 15-116 (GM P/N 12323913) - 300 viscosity for non- Harrison/Delphi manufactured compressors. R-134a Systems PAG lubricant – ACDelco P/N 15-118 (GM P/N 12356151) – 600 SAE or 150 ISO viscosity for all R4 and A6 compressors. For all other ACDelco supplied service replacement compressors, use the 46 ISO viscosity universal PAG oil, ACDelco Part Number 10-5040 (GM #89022191) in the 8 oz. bottle or Part Number 10-5026 (GM#88901445) in the 8 oz. cartridges. A/C oil injector #J45037 should be used with the 10-5026 cartridges. There are no Ester lubricants approved by ACDelco for retrofitting R-12 systems or for use in R134a systems.

quote FLUSHING There are several A/C recovery equipment manufacturers that provide a refrigerant flush option. Use of refrigerant flush is ecologically and economically favored over solvent flush. Flushing is extremely effective for lubricant removal. Be sure to rebalance the refrigerant system lubrication charge after flushing. ACDelco recommends flushing R-12 systems using only R-12 refrigerant. This procedure can be accomplished using the Kent-Moore R-12 charging cart (J-39770) and a special flush adapter (J-39807). Kent-Moore can be reached at 1-800-345-2233. ACDelco recommends flushing R-134a systems using only R-134a refrigerant. General Motor’s service bulletin 83-12-21 should be referred to for flushing R-134a systems. This procedure requires use of a special Kent Moore flush adapter (J-42939), which can be employed with several recovery/recycling machines. Always follow the guidelines from the manufacturer of your particular equipment. ACDelco does not approve the use of any other types of flush agents or solvents. It has been found that residual amounts of these flush agents may act as solvents and affect the integrity of seals, O-rings, and other components. Residual non-approved flush agents when not properly removed dilute refrigerant lubricant. System components will not be covered by the ACDelco warranty if non-approved flush agents are used.

quote LEAK DETECTOR R134a is a smaller molecule, has no chlorine atom and the system requires smaller charge weights. Therefore, it requires tools specialized for the refrigerant and for both active and passive leaks. Electronic Leak Detector Active (continuous) refrigerant leaks are quickly located with electronic leak detectors meeting SAE J-1627. ACDelco recommends employing detectors, which include reference check fluids. Leak Dyes Intermittent or passive leaks require a dye to determine the location. These leaks can be temperature, pressure, or vibration related. ACDelco offers the following air conditioning dyes for use in R-12 and R-134a refrigerant systems. These professional dyes require UV light to locate leak site. The use of non-approved tracer dyes may affect the integrity of seals and O-rings, causing leaks and other compressor complaints. R-12 Systems – Leak Dye ACDelco P/N 12345926 (GM P/N 12345926) R-134a Systems – Leak Dye ACDelco P/N 15-120 (GM P/N 12346287)

quote AIR CONDITIONING REMINDERS • Use PAG lubricant with R-134a or when retrofitting to R-134a. • Use mineral oil with R-12. • Lubricate O-rings and threads only with mineral oil (525 viscosity). • Change the accumulator if over five (5) years old, damaged or the system is found to be contaminated with sealants. • Keep PAG lubricant containers sealed. They absorb moisture quickly. • Measure and replace the exact quantity of lubricant when replacing a compressor. • If required, flush R-12 systems with R-12 and R-134a systems with R-134a. • Install an in-line filter and suction screen if contamination is suspected. • Insure less than 2% R-12 remains in the system when converting to R-134a. • Use a full measure of PAG lubricant when converting the system from R-12 to R- 134a. • Evacuate the system of all air to eliminate oxidation of lubricating oil. • Keep all foreign substances out of the system. Air over 3% can cause compressor noise and reliability problems. • Use new O-rings or seal washers if a connection has been disconnected. • Use only approved leak detection dyes. • Accurately weigh charge–Do not employ cans. CAUTIONS • Lubricating O-rings with PAG lubricant could corrode fittings. • Leaving the air conditioning system open allows moisture in components. • Ester oils do not provide proper lubrication and can cause system failures. • R-134a systems cannot be retrofitted to R-12. • Use of R-11 or R-22 will damage the compressor and contaminate refrigerant recovery equipment. • Mixing refrigerants will damage the compressor. • Blends require by law special fittings and dedicated equipment, and cannot be recycled. • Blends are not approved by General Motors, and will void the warranty on system components.

Interesting they don't recommend lubricating o-rings with PAG oil, and that only the R4 and A6 compressors use the PAG150 viscosity oil, and others should use the PAG46.

quote Originally posted by RWDPLZ: Very interesting read ...

What I still don't understand is why ACDelco doesn't approve ester oil, especially since many other sources recommend using ester oil in preference to PAG for R-12 to R-134a conversions. It may be as simple as that all their durability testing was done using PAG and they just don't have any good engineering data on ester oil in GM/Harrison compressors. It's equally possible that they did test with ester oils and found them unsatisfactory for some reason. One thing is virtually certain ... ACDelco is going to deny any warranty claim for a failed compressor that is found to have ester oil in it.

FWIW, I seem to remember several sources stating that you should never mix PAG and ester oil in the same system. Again, I don't think I've ever read why, but it's possible that they can react to form a harmful residue.

quote Interesting they don't recommend lubricating o-rings with PAG oil, and that only the R4 and A6 compressors use the PAG150 viscosity oil, and others should use the PAG46.

This is one of many reasons why it's important always to follow the directions provided by whoever manufactured or rebuilt your compressor. Recommendations for lubricant type and viscosity do vary, and you want to be sure to use whatever is recommended by whoever is going to have to make good if there's a failure covered by warranty.

[This message has been edited by Marvin McInnis (edited 02-27-2012).]