Thread: RR Classic AC Compressor

depending on what you need how and when

I'm again looking into starting with hychill for doing regass work.

feel free to drop me a DM.

Hi Simon,
Just a quick note:
I don't know any frigies in your location, you'll need to ask around local workshops to see who they use for frigie work and how good are they (word of mouth is the only way these days)

Before you proceeed - Unless you've UV dye tested the system and identified ALL the leaks, I would stop and do this first before going any further with a replacement compressor and r134a regas.

Locally you can get the correct compressor without having to buy from overseas. Cooldrive and Ashdown (now NAPA and repco etc ad infinitum) have parts.
However:

The evaporator is the weakest link in the RRC's HVAC. not the compressor or condensor.
The evaporator is known to leak like a sieve, and is the domain of many a misdiagnosed HVAC system and the "bang-gas" refills.

Suggest you vac it down, check it every 15 mins for 3 hours, possibly leave overnight if you can, and see if it holds.
then uv dye and check pressures and switch functions. stop and check for leaks with UV, identify and rectify all leaks before proceeding.
hoses become more permeable with age, so if they are more than 10 years old, just wholesale replace (refabricate) ALL of them. It's cheaper in the long run.

So many people do not understand the different line pressures and system pressures and operating parameters when it comes to the different refrigerants.
The truth is, there is NO correct substitute for R12 in the original system. It matters not what you want to sub for it.
YES, you can sub 134a with a minimum of fuss, but the permeability of the pipework (yes they are all permeable) is a different spec for 134a than R12, and so are operating pressures.

Pressure is ultimately the issue and the volume of refrigerant (charge amount in grams) in the system.
This is why Frigies have a license - with knowledge to back up their qualification.
If you want to DIY, there is nothing wrong with doing all the component R&R and making hoses etc, but you still need to flush, charge and refill the system properly. You also need to know the system volume and the compressor, condensor and evaporator need to be correctly sized.
That requires knowledge, and regassing requires a license.

Hychill is a dry gas and requires a very specific oil amount, nonetheless, if the system settles for longer than average periods, the lubrication is insufficient and premature damage / wear is the result.

That will render your "repair" useless in an unsatisfactorily short period.

There is no debate on the hychill vs R134a / R12 / 410 / 610 / ad infinitum branded refrigerants.

What you need to know is that despite the environmental concerns, R12 was the best gas for an automotive application. and non-flammable. It is now illegal to dispense into a new system. Recovery is controlled and requires a license.
Some very specific circumstances permit the use of r12. Your use case falls outside this unfortunately.

Suggestion is to consult with a frigie - one who does auto air is knowledgeable in the associated electricals, but ANY qualified frigie will be able to correctly size the condensor, compressor and evaporator to accommodate correct refrigerant, associated required line pressures and temperatures to optimal parameters.

Some things to consider- if you are going to DIY and upgrade your system:
Condensor with an integral subtank. This increases efficiency and reduces the quantity requirement of refrigerant in the system.
Variable speed brushless fan with PWM thermostatic control for the HVAC with integration into the vehicles thermostat switch, so it serves dual purpose as push-through cooling to aid the viscous fan at higher temps.
Variable speed evap blower fans which are pwm controlled and brushless - reduced electrical load and more efficient air delivery (and quiet) get rid of the blower fan resistor for good.
Electronic thermostat for proper hysteresis loop control and prevention of icing in high humidity scenarios.
a dedicated electric element heater on the evaporator for de-icing (should it occur) instead of rerouting hot air from the heater matrix.
an automatic climate control mixer from the heater matrix (requires additional temp sensors at vents and on the return air) something you can pillage from a later model vehicle in many cases, and adapt to your situation - There are various types, but manual control is still fine, just not as efficient.
re-routing of HVAC lines in engine bay away from the obvious heat sources, and properly insulate both lines, not just the delivery line.

All of this is designed to keep compressor load (runtime) on the engine to a minimum - which reduces fuel consuimption and increases the HVAC system efficiency.

a consultation with a frigie before you embark on this, would be beneficial - many frigies work closely with auto sparkies as well, so a good chat will result in you coming away with a proper plan if you intend to DIY.
A good frigie won't push you - but at the same time, you need to understand they have to warrant their work - so that may very well mean two things:
Your work is not up to their professional standards or the EPA's requirements (license revocation) which means they are between a rock and a hard place (and want to keep their license)
They would prefer to supervise your contribution to the project, and you would have to be willing to accept that they will charge for their time as well as any labour that is required to "fix" things you did not do correctly (regulatory compliance).

Do it once, do it right. HVAC becomes an expensive problem if you ignore that rule. (and you will kick yourself later if you choose to ignore it) - You can find plenty of youtube vids on flammable repurcussions resulting from inappropriately repaired / designed / constructed HVAC systems - and it's not just hychill for the record.

Be aware that the modern refrigerants are not far off being flammable themselves in the right circumstances.

If compressors and hoses did not leak, and motor vehicles did not have accidents, we'd all still be loving R12 in motor vehicles.

There are plenty of good frigies out there who would be willing to discuss this kind of work and help you with your project.

You will absolutely have to ask around and get word of mouth from trusted mechanics, find out who they use.

good luck.