I'm planning to do some air conditioning upgrades when funds allow.

The original 1989 R-12 system worked fine until a couple of years ago. The system worked well for about 16-17 years or about 180,000 km (110,000 miles) and I would like to do a good quality job. Being in Canada, I do not have a legal source of R-12 to recharge so I have to work with R-134a. I don't wish to attempt any other form of refrigerant.

The A/C shop could not conduct any refrigerant pressure tests because there was nothing in the system although a 12 hr pressure test did not indicate any leaks.

That being said - I am willing to put some effort and expense (but not excessively) into getting the A/C system working and improved. It appears that I could do this by converting to a parallel flow condenser, replacing the A/C hoses, installing a rebuilt compressor, new drier, and possibly the expansion valve. The evaporator will stay as is unless I really have to replace.

My questions are:

1) Is there a W124 parallel flow condenser that will directly replace the original condenser? Is this a custom job and, if so, how big a job is it?

2) Replacement A/C hoses are reasonable cost EXCEPT for the fuel cooler line. Can the hoses on this device be replaced with the new barrier hose? Or do I have to buy the whole thing? If installing a parallel flow condenser do I have to install modified hoses? (ie a bit longer or different routing)

3) Is it worthwhile to replace the single aux fan with the dual fan setup of later W124's? I suspect the dual fans increase the airflow over the condenser to improve cooling capacity but is it worthwhile? How big a job is the replacement?

4) Should I stay with the originally spec'd Denso 10p15c compressor or is there a better model (greater capacity) that can be effectively used.

5) Are there any other parts that I should consider in this rebuild and upgrade plan?

I would really appreciate some assistance with these questions so I can start collecting the parts and then plan getting the work done.

Many thanks in advance,
Paul