With many cheap "remanufactured" automotive A/C compressors the part most often that they change is the shaft seal. That's the part that most often fails. It would take too much labor and parts cost to take apart a unit that has failed and to rebuild everything. The A/C Delco rebuilt compressors were done with a complete rebuild and perhaps the Four Seasons brand also, but look at the cost. Many times completely failed compressors "grenade" and then chance of rebuilding are slim. Budget rebuilders typically buy junkyard compressor units, spin test them to see if they pump and then clean repaint, replace the seals and test -done.
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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, 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 "