Jerry Heasley
June 10, 2014

Neil Thompson has been upgrading the 289 under the hood of his '66 coupe for quite some time. Current upgrades include a chrome alternator, an Edelbrock aluminum intake topped by a Holley four-barrel carburetor, and a custom billet aluminum air cleaner housing to spice things up.

The ancient factory A/C compressor looked out of place in the updated shiny engine bay, not to mention a major power drag on the 289 when the clutch engages. That's why Neil had long ago disconnected the compressor and opted to sweat through the summers on the South Plains of Texas to give the 289 a little more power.

The A/C system in this ’66 had not had a charge in years, but if your system still holds R-12 it must be reclaimed by an A/C shop before you open the system. Remove the OEM A/C compressor by disconnecting the single clutch wire, suction and discharge hoses, and the bolts from the bottom bracket. Leave the factory idler assembly and bottom bracket on the front of the cylinder head.

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What he needed was a modern axial A/C compressor, so we called up the guys at Scott Drake and ordered one its compressor conversion kits (PN 50-3066) for Neil's '66 Mustang. The kit is designed to fit the 289 and stock A/C hardware and fits his needs perfectly. The Sanden compressor in this kit is small and efficient, plus Neil ordered his compressor polished to add a little more shine to the already spiffed up engine bay. Now, his Mustang's engine bay will look as cool as he'll feel when the A/C is turned on.

A professional mechanic by trade, Thompson led us through the steps to remove the old compressor and install a new one. However, the general removal and installation steps are very basic and only require your typical hand tools. You can easily convert your Mustang's stock A/C system over to the more efficient Sanden setup and then hit up a local A/C repair shop to have them handle the evacuation and recharging of the system per the kit's instructions.

Remove the grille and hood latch assembly to gain access to the A/C condenser. The condenser must be removed in order to replace the condenser-mounted drier assembly. Disconnect the condenser’s lines and unbolt it from the core support to remove it.

Remove the old drier from the condenser. Inspect the condenser to make sure the fins are attached to the tubes. Loose fins will decrease cooling capacity, in which case the condenser should be replaced. The old condenser must be flushed of any contaminants. Neil is a professional mechanic and recommends using rubbing alcohol as a flushing agent.

Flush the system of contaminants by blowing compressed air through the condenser. Pull the evaporator case under the dash and remove the expansion valve to pour rubbing alcohol into the evaporator and then blow compressed air through the lines. A white or tan residue from either part indicates excessive internal corrosion and means the part(s) need to be replaced.

Attach the kit’s new suction (low side) hose with fitting to the evaporator case. You will re-use the high side (discharge) hose that also attaches to the evaporator case.