72 A/C Compressor Clutch Replacement

[brown7373]

IUs it possible to replace the compressor clutch without discharging the A/C system? Mine fried yesterday, but I am pretty sure the rest of the system is fine.

Here is the sequence of events. Last week, I smelled electrical component burn smell. I reached under the control unit and the blower switch was very hot and some melted goo burned my finger. I replaced the switch with a used one I had. The A/C worked fine, but I had to giggle the switch to get it to make contact and work on 2nd speed only. So I bought a new switch, but not installed yet. So yesterday, with used bad switch, I smelled the burning electric smell again, then I could feel the engine straining to turn the compressor and the system lost cooling. I shut it off and the clutch was so hot, all the paint was off it and it was sizzling hot.

First, is there a procedure to replace clutch without discharge or do0 I need a whole compressor and clutch?

Could a bad switch cause a clutch failure, since the compressor shuts off when the blower switch is off? Might I have a bad blower motor causing switches to fail?

Factory A/C with 134a and POA calibrated for 134a.

[dutchmanz]

Sounds like you will need a new clutch coil along with the hub and clutch plate. The inner seal has nothing to do with the clutch. It is sealing against the shaft. The correct puller is all you need to safely remove the clutch plate. Remove a snap ring and a rubber mallet will take the hub off. Same thing for the coil behind the hub, just no snap ring. An installer is preferred to but the plate back on after the coil and hub. Make sure you set the air gap for the clutch. It's a fairly easy swap. You don't even have to remove the compressor from the engine depending on your fan shroud. I hate to be "that guy" but the factory service manual has the procedures. The A6 was used into the late 80's on trucks.

[brown7373]

I just realized that I have 2 72 Chevy manuals. There isn't anything on it in the Service Manual, but the Overhaul Manual has the procedure. I am used to the Pontiac and Oldsmobile having everything except Fisher Body in the Service Manual.

I don't have the tools specified in the Overhaul Manual ( Clutch Hub Holding Tool J-9403, Hub and Drive Plate Assembly Remover J-9401, Hub and Drive Plate Assembly Installer J-9480). Can this job be done properly without these tools? Can I jury rig something else to work or am I better off taking it to a shop that has the right tools?

[dutchmanz]

It can be done without tools. Especially since you are replacing the old parts and their condition after the fact isn't important. May want to try advance or autozone and see what he tool loaner program has.