A/C compressor - Seeking Edgeucation

[71CHEVYSHORTBED402]

I'm working on a rebuilt original A/C system, getting ready for a maiden start soon. I have all the connections figured out, o-rings and such. I'm leaving the connections snug only for a pro to tighten things up.

I'm wondering if it's A-ok to connect the compressor belt so long as the A/C isn't run? It will be charged with R134A after the truck is running.

I've never tensioned an A/C belt before. Near as I can tell I can do that with a pry bar against the compressor and its lower bracket, but is there a cleaner way to accomplish this?

Thank you

[Richard]

No problem putting the belt on. The compressor will not run unless the clutch is engaged. For extra insurance if controls are on leave the wiring disconnected to it. With no charge in the system the low pressure switch would prevent compressor from coming on as well.
Do not know of any other fancy way to tighten the belt. Maybe wrap your choice of pry tool with a rag to try and save your nice paint.

[mr.mud1]

hi Tony,i just did what you're asking,my system will be charged after the truck is running.i left the wires to the clutch off and took a long pry bar with a rag on the end,down behind the compressor til i got to the head near the exhaust manifold and pulled it tight,unlike the previous owner or whoever worked on it,put a bar down on the valve cover and pulled,smashing in the valve cover.with a long bar,you won't have to pull very hard.take care.Greg

[71CHEVYSHORTBED402]

Darn previous owners............

Thanks a bunch for the info.

[Davidf]

Originally Posted by Richard

No problem putting the belt on. The compressor will not run unless the clutch is engaged. For extra insurance if controls are on leave the wiring disconnected to it. With no charge in the system the low pressure switch would prevent compressor from coming on as well.
Do not know of any other fancy way to tighten the belt. Maybe wrap your choice of pry tool with a rag to try and save your nice paint.

I do not believe a factory a/c setup has a low pressure switch.

To the OP: Avoid over tightening the belt as that just puts undue pressure on bearings. Why leave the tightening of the fittings to a pro, nothing magic about tightening up the line fittings...just don't be a gorilla. If are converting to R134a, did you flush the system to remove all the mineral oil? Are you upgrading the condenser? If you leave the line fittings loose, you risk allowing moisture into the new (assumption) receiver/drier. Not the end of the world, but will require a longer evacuation time to boil out all the moisture and dry the desiccant.

[71CHEVYSHORTBED402]

Originally Posted by Davidf

I do not believe a factory a/c setup has a low pressure switch.

To the OP: Avoid over tightening the belt as that just puts undue pressure on bearings. Why leave the tightening of the fittings to a pro, nothing magic about tightening up the line fittings...just don't be a gorilla. If are converting to R134a, did you flush the system to remove all the mineral oil? Are you upgrading the condenser? If you leave the line fittings loose, you risk allowing moisture into the new (assumption) receiver/drier. Not the end of the world, but will require a longer evacuation time to boil out all the moisture and dry the desiccant.

Yeah maybe I'll tighten things up after it's assembled. My instinct was per the torque setting, I don't have the tool gauge, but the pros probably torque to feel anyway.

The entire system is rebuilt for 134a. Installed the compressor. I'm a brake brake booster away from finishing the bay for fenders. Long haul.