Join Date: Jun 2002
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well i've been looking into fixing my ac system on my '87 for a month or so (to no avail but mainly because i'm too lazy to try it... ) but after lots of looking into it here'* what i know:
First you wanna see if you can find out why your compressor locked up. If it locked up due to just age, etc that'* for the best, but if it locked up because of deterriorated teflon rings in the compressor (this is referred to as Black Death in the car a/c world) then you'll have to look into how much damage that caused.
With deterriorated teflon rings, chunks of the rings (usually seen as lots of BLACK gunk in your lines, condenser etc) are broken out of the compressor and into the system. This usually clogs the system and causes compressor failiure (the clog in the system keeps the compressor from getting refrigerant/oil (the oil travels with the refrigerant) and thus the compressor fails.
If your system suffered this Black Death, you may have a good amount of work ahead of you (replace your lines to and from compressor, check condenser to see if it is cleaned out via flushing or if not, replace it, same goes for evaporator but less likely that the black gunk would have made it so far in the system).
Assuming that'* not the case here'* what you should do
Remove your old compressor, remove old accumulator (might as well get a new one of these to ensure your new system is in top shape, its only about 60-80 bucks new from a parts store). NOTE: the amount of refrigerant your system needs is usually listed on top of your accumulator on a yellow sticker, note this amount before getting rid of the old accumulator
At this point we're ready to begin oiling / final installation, do the following when you're ready to install the compressor / accumulator, and seal up your sytem as soon as you can (i.e. install everything and flush all in one fell swoop)
Using a flushing solution and shop air, flush the rest of the system (i.e. the evaporator and the condenser).
Similarly, flush out all the lines. (replace your old orifice tube too, its about $5 bucks).
NOTE the new components of your system, i.e. the compressor and accumulator are not to be flushed, (they're new and clean already!)
For the next step, make sure you have oiled up the O-Rings (any that you see and can find on the hoses) with some oil, if you can get your hands on new a/c o-rings, even better! Put the o-rings back in place once they have been oiled.
Now that everything'* been flushed, drop in the oil for the compressor into the compressor'* suction port. (I'm at the library here at Virginia Tech between classes so i dont have the exact amount of oil to put in, i BELIEVE it is 8 oz but don't quote me, i'll get you a better figure later tonight when i get to my appartment where i have a shop manual, in fact since my manual is for my '87 i recommend you get the amount of oil from someone else------------)
As soon as you put the oil in, mount all the lines on the compressor to make sure nothing else gets in.
Now move on to the accumulator, drop in the correct amount of oil for the accumulator (4 oz i believe SOMEONE ELSE CONFIRM THIS FIRST!!), and mount that immediately as well.
Now your system should be nice and closed and nothing should be getting in or out.
Next step is evacuating the system--
You will need a vacuum pump to evacuate the system. Vacuum the system down via the low pressure valve to (WILL GET YOU THIS FIGURE LATER TONIGHT). Once the system is vacuumed down to this pressure, disconnect the vacuum pump and let the system sit for ~45 minutes.
After 45 minutes, check the pressure of the system, it should not have changed from when you removed the vac. pump. If it has changed (I.e. pressure gone up), you have a leak somewhere (proceed to curse at that point!) Fix any leaks if your pressure doesn't stay down, iif you can't fix the leaks, i dont think i have to tell you that your system won't be blowin cold (or probably even running) for that long.
Next you have to turn the compressor a good 10+ times by hand. Be sure you turn not just the compressor pulley but the clutch itself. (it should be somewhat hard to turn it, the pulley on the other hand should turn with very little effort) There is a tool available to help you turn the compressor, i find that i can t urn my new compressor by hand so I don't need a tool but some people do need that tool (The tool is sorta like a Y shaped wrench that grabs on to the couple of screws on the compressor'* clutch so you can turn it easier, i believe it to be available for rent or purchase at many chain parts stores).
Now that your system has been flushed, components have oil, and has been evaccuated, all that'* left is to put in the refrigerant itself.
Find the low pressure valve on your system and give it the correct amount of refrigerant based off of the number you noted on the top of the accumulator earlier. DO NOT OVER OR UNDER FILL THE SYSTEM.
***QUESTION: DOES CAR HAVE TO BE ON WITH ENGINE RUNNING WHEN DOING THIS INITIAL CHARGE??? PLEASE RESPOND!!! I WILL CHECK SERVICE MANUAL TONIGHT AND GET BACK TO YOU***
Your a/c system should be up and running good as new now!
I wouldn't use the captured R134a you got from the old system, might as well get new oil and refrigerant in there. What'* an extra 15 - 20 bucks for nice new refrigerant?
Regarding the Black Death thing, if your system had this going on, try your best to make sure there are no clogged passages in the condenser, sometimes flush solution comes out clean and one thinks he'* finished flushing but doesn't know there is an entire clogged passage of gunk! That'* why its a good idea to replace the condenser IF you have black death, if not then you're probably fine with just flushing.
If you don't have a vacuum pump but do have an air compressor, i have seen small boxes that convert that pressure into vacuum (i.e. turn your air compressor into a vacuum pump), I am not sure how well these work, in any event so long as whatever "vacuum pump" you're using can get the system down to the pressure it needs to be, you should be fine.
Don't skimp on small things like buying new o-rings if you can and lubing them up, and buying a good guage etc to read pressure... these things will obviously pay off in the long run.
I know it'* weird that you put oil in the system, then evacuate it! But that'* the process (the oil stays in there).
Use the right type of oil for your AC system, there are various available:
PAG, ester oil, (one more i think too).
ANYONE KNOW WHICH HE SHOULD USE? I'm assuming Ester OIl though! They sell these in small little cans (they are not pressurized).
Good Luck, I hope this helps,
ask any questions and we'll see if we can help.