Eric
If it is the R12, you will need to renew the flexibles as well, as the newer gasses permeate the OEM hoses, believe it or not the molecules of R124 are smaller, apparently.
Greg

 

Actually Greg The hoses are the part of the system, with the least issues. IF at all, then the rubber O-rings between the connectors are the issues BUT, as my expert friend (he has a so called "Meisterbrief" which means he is a state proven Master of Science, is you want to call it that) who only does AC systems day in day out, no matter if house, factory, refridgerator or what so ever, says, the normal systems that operated on R12 will take R134a with no worries... 1,1,1,2-Tetrafluoroethane (R134a) may have smaller molecules compared to Dichlorodifluoromethane (R12), but it will fluctuate from systems with modern materials as well.

As it is LESS hazardous than R12, a leakage of up to 10%/year is acceptable and normal. Modern cars with R134a are normally regased every 5 years. This is where R12 was better, as it wouldn't seep through the materials... But if it leaked, it would be worse for "the planet".

So, I would have no worry using the old hoses, if they aren't brittle and can hold a vacume/pressurisation.

All is better than R1234yf as used today, which basically kills you upon contact and when it burns, kills the people around it really quickly upon contact...

In a few years time, we'll be able to upgrade (even older cars!) from R134a to R744 (pure CO2). CO2 is as we know not poisonous to us humans, nor will it catch fire.

Back to what I wanted to write regarding R134a as a drop in. Important: USE THE RIGHT OIL! That is the most important thing. The oil needed for R134a is different to that, what the A6 Harrison compressor wants, so you need a R134a compatible oil which will still work with a mineraloil requiring compressor...

Heck, I sound like a nerd

 

AC shops are rare here, and if, then they cost a fortune. BUT I know where I get my cars regased - free of charge Once the XJ-S is running again, in goes some R134a (with a future supply incase I need more ) and that free of charge...

 

Thanks for the corrections Daim. Seems they saw me coming!
Greg

 

No problemo Greg... I didn't correct much, just "extended" your post a little bit.

As said, modern AC hoses with modern materials made for the R134a systems, aren't totally "enclosed". It is just annoying that your AC will work great for about 4 years (unless something dies in the meanwhile) and in the 5th year will start to warm up and get on your nerves...

SOMETIMES the AC will hold longer. My C30 didn't even make 5 years, as a metal pipe sheared off before the freon could become low... An aluminium pipe which is connected between the compressor and the bodywork!!!! What an idiotical construction... In the service book I got with my XJ8, the AC was regased around 2000 the last time and then, after hitting a trailer coupling in 2014, was left open. New radiator and it is still solid... Hoses are all original (and look it! ).

AC systems are normally totally troublefree and work normally, no matter what is in it, with a certain "seepage" acceptance...

 

If you open the system up, i.e. disconnect hoses tape up the ends as quickly as possible to limit the air getting into them. Air has moisture in it and moisture destroys A/C systems from the inside. That's why they have the drier. If the system is old or you suspect a problem replace the drier at the same time. Either way before you re-charge/regas the system you'll need to evacuate it. This is easy to do and you don't need a shop to do it. Just the right tool/vacuum. After that it is just a matter of charging the system with the correct volume of R134.
If the system used R12 before you MUST change out the oil in the compressor. R12 oil is not compatible with R134. There is a drain plug that makes this an easy job. Don't overfill it with the new oil or you will increase internal pressures beyond acceptable and may cause compressor failure.

 

The A6 compressor has two oil fills. One internal and one external. External = is filled in with the freon. Internal = is in the moving section of the compressor.

The problem with water/moisture in the AC isn't as much the destruction it can cause but the corrosion in the compressor. The compressor will rust inside and the pistons (if a piston compressor) will be badly damaged. This is - with many other reasons - why the pressure switch will also stop the compressor, if no pressure can be built up (i.e. no freon in the system). The magnetic clutch is then uncoupled to make sure nothing goes wrong.

The rest of the system, the condenser, the evaporator, hoses, don't really have issues with moisture. Also, if you do get a build up of fluid in the system, it can't be compressed - lock up risk! - so the compressor is again in danger.

Before using it again, as already said, fit a new drier cartridge and have a vacume sucked for about 30 mins instead of 10/15 mins (depending on the machine used). This will drain all the possible fluid out of all other components.

 

Thank you all for this useful insight of the A/C world.
I will consider my options on what to do right now, and I am sure I will re-read all of this in a year, or so I hope ...

 

As per THIS POST

Well, this is what happens when I accept a clean up challenge!



I eagerly await your response!

 

????


I messed up on post on R12 vs R134, it is in the clouds, but not the ones that store data!!


I forgot to include the salient point anyway. Here it is.


Beautiful work on marvelous machinery. Just too pretty to add oil that will leak and mess it all up???


Carl

 

Ha, seems I hit your weak spot, you did a lot better now than you were happy with some month ago.

Daim, that starts to look absolute amazing, and there is no doubt on who should win right now ...
Love your galvanized parts, outstanding!

I will be back!