AC Failure & Restoration questions

Pete_89T2 · 04-17-2017, 09:36 AM

Well the AC compressor on my FC finally crapped out in spectacular fashion this weekend - compressor seized up solid while cruising on the highway! This resulted in a mangled AC belt, which when it snapped, managed to frag the PS belt before I could pull off the road. As I was pulling over onto the shoulder, the engine died and refused to restart - that was due to all the rubber bits of belt that were now covering the new FFE crank angle sensor. After a quick roadside clean up of the sensor, the car started & got me home, minus power steering.

So since I want to restore my AC, it looks like I'll need to rebuild most of the system and switch over to R134 refrigerant. On to the questions:

1. Confirm the parts list below that I'll need to tackle this job, and share any good recommendations for AC parts sources?

I know I'll need a new/rebuilt compressor, a new receiver/dryer, all new O-rings/seals for the entire system, and I probably should get all new hoses and a new condenser to support the switch to R134.
I'm thinking the evaporator core and the all the hard lines can be reused, after they are properly flushed & cleaned of all the old R12 compressor lube.
I'm thinking a new condenser is needed because: (a) It's very difficult to flush/clean 100% of the old R12 lube out of a condenser (tiny passages), and (b) A larger and/or more efficient condenser would benefit an R134 switch, as the FC's AC system was marginal running with R12. I'm thinking new rubber lines are needed because R134 needs the newer "barrier" lines, and my old R12 lines are now almost 28 years old
Most of the "complete AC repair kits" I've seen online include a new expansion valve/orifice - assume I'll need that as well?
The stock FC system has a refrigerant pressure switch on the high side plumbing, and a temperature switch on the evaporator core. Both switches are normally closed (NC), and are intended to disengage the compressor clutch when the respective pressure or temperature condition is met. IIRC, the temp switch opens at temps below 35*F or so, just before the evap core would freeze up. Not sure what pressure the pressure switch opens at, but since it was designed for an R12 system, I'm guessing I'll need a different pressure switch to work with an R134 system? If so, what should the switch pressure spec be?

2. After doing a little compressor shopping, I'm finding that the original Denso compressor my FC has (AC installed in Japan during assembly) is NLA or just very hard to find, but the Sanden compressor (port/dealer installed unit) is readily available. Would switching to the Sanden matter, assuming all the fittings/plumbing are new?

Thanks!

04-17-2017, 09:36 AM	#1
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD Posts: 874 Rep Power: 16	AC Failure & Restoration questions Well the AC compressor on my FC finally crapped out in spectacular fashion this weekend - compressor seized up solid while cruising on the highway! This resulted in a mangled AC belt, which when it snapped, managed to frag the PS belt before I could pull off the road. As I was pulling over onto the shoulder, the engine died and refused to restart - that was due to all the rubber bits of belt that were now covering the new FFE crank angle sensor. After a quick roadside clean up of the sensor, the car started & got me home, minus power steering. So since I want to restore my AC, it looks like I'll need to rebuild most of the system and switch over to R134 refrigerant. On to the questions: 1. Confirm the parts list below that I'll need to tackle this job, and share any good recommendations for AC parts sources? I know I'll need a new/rebuilt compressor, a new receiver/dryer, all new O-rings/seals for the entire system, and I probably should get all new hoses and a new condenser to support the switch to R134. I'm thinking the evaporator core and the all the hard lines can be reused, after they are properly flushed & cleaned of all the old R12 compressor lube. I'm thinking a new condenser is needed because: (a) It's very difficult to flush/clean 100% of the old R12 lube out of a condenser (tiny passages), and (b) A larger and/or more efficient condenser would benefit an R134 switch, as the FC's AC system was marginal running with R12. I'm thinking new rubber lines are needed because R134 needs the newer "barrier" lines, and my old R12 lines are now almost 28 years old Most of the "complete AC repair kits" I've seen online include a new expansion valve/orifice - assume I'll need that as well? The stock FC system has a refrigerant pressure switch on the high side plumbing, and a temperature switch on the evaporator core. Both switches are normally closed (NC), and are intended to disengage the compressor clutch when the respective pressure or temperature condition is met. IIRC, the temp switch opens at temps below 35*F or so, just before the evap core would freeze up. Not sure what pressure the pressure switch opens at, but since it was designed for an R12 system, I'm guessing I'll need a different pressure switch to work with an R134 system? If so, what should the switch pressure spec be? 2. After doing a little compressor shopping, I'm finding that the original Denso compressor my FC has (AC installed in Japan during assembly) is NLA or just very hard to find, but the Sanden compressor (port/dealer installed unit) is readily available. Would switching to the Sanden matter, assuming all the fittings/plumbing are new? Thanks!