How to re-charge '87 Air Con - 944s

[tartan_rob]

So I bought a kit off fleabay and located the high and low pressure ports. I have 2 questions:

1) What port do I use? a) the port inside the engine bay beside the n/s/f upper shock mount or the port on the AC Pump?
2) What kit can I use? the ports are different sizes to the std kit I bought?

Thoughts appreciated?

R

 

[scam75]

I have looked at these kits. Unless your system is modified you will have a system (that in the distant past!) ran on R12 gas and with seals and components suited to R12 gas. All the fleabay stuff seems to be R134a or equivalent which I believe is no use to a system that once ran on R12 without suitable modifications!

Enlighten me if I'm wrong. Also worth noting R12 is NLA and possibly illegal now!

And if you have cracked this on the cheap, let me know asap as the sun seems to be thinking about coming out and icy cold air in my cabin would be a joy! []

Cheers

Stuart

 

[edh]

If you're very lucky, a re-charge will help, but there's always the question "where's the original refrigerant gone?"

It's likely that your system will not hold pressure so a re-charge, even with the right gas, won't work.

The pipes have rubber sections that become porous over time.
The condenser may have corroded or become holed
The receiver dryer will need changing (probably)

Also your compressor may or may not work.

To change from R12 to R134 I understand you need the system purging first as the two systems are not compatible - that's what my aircon man told me.

I'd suggest you get an aircon specialist to check for air tightness (does it hold a vacuum) first before you do anything else. Then take a deep breath before you look at the cost of sorting it all out. Cool-it in Dorset are the experts in 944 refrigeration...

I've been there & spent a fortune to get working aircon in a 944 turbo

Good luck

 

[scam75]

That sums it up perfectly! I am resigned to going fast with all the windows open, traffic jams and red lights suck!

Stuart

 

[edh]

btw when I say I've been there - I mean I've fixed my aircon, not I've been to Cool-it

Also i understand that R134a is a smaller molecule so even more likely to leak than R12. My first attempt at working aircon got me to Le Mans in relative comfort, and luckily the trip back was done at night, because the system had lost most of its new gas by then.

 

[RS2000CUSTOM]

http://www.ebay.co.uk/itm/RETRO-PRO-AIR-CON-CONDITIONING-CONVERSION-KIT-R12-R134A-/291146005713?pt=LH_DefaultDomain_3&hash=item43c9a77cd1

 

[tref]

I haven't used the EBay kit, but I have used Coolit... For the sake of an extra few pounds I'd rather know it has the correct amount of oil in the system - I understand the correct amount combined with regular use will prevent the gas disappearing through the hoses quite as fast, but too much can block nozzles and cause other problems. If a regas isn't going to fix it they will tell you exactly what it needs/where the leak is... And can rebuild a compressor! I'd like to say no connection other than a satisfied customer... But they also happen to be good supporters of PCGB in Dorset (other equally helpful independents are also available!)

 

[tref]

Btw, after Coolit first got my air-con working it worked 6 years before it needed a regas, and I think then it was possibly because it was idle for a year or two (engine problems). It has subsequently worked for a year so far without problems... Actually, it might be two years now!

 

[ChasR]

I have been eyeing up the above kit myself truth be told, and am considering taking the plunge.

With my 944 I had it tested to see whether it held a vacuum (thus seeing if there is a major leak). It did hold vacuum, so the next stage for me will be converting the car to run on R134a.

When I spoke to the AC chap he mentioned that there would be a few things he would do, including:

-adapting the fittings so that they will take the modern clip on fittings which suit R134a systems (the 944 comes with screw on fittings)
-Run a fluid through the system so as to convert and condition the system for R134a (he quoted way more for the fluid than RS2000CUSTOM link).
-From this moment R134a can be added in.

I was quoted around £200 for the above to be done.

However, there have been a few caveats with what has been mentioned above
-The system is meant to be free of any moisture or old gas before the above can be done (I guess with the vacuum test I should be OK).
-PAG fluids are not meant to react well with the above (the cans you buy from Halfords have this as do I guess gas being filled via AC vendors but POA fluid is said to be fine (maybe this was the fluid the above conversion kit has)
-The high side port (the top port I believe in the 944) should not be touched when refilling the system with the system running. Only the low side should be.
-Finally, because IIRC R12 systems ran a lower pressure than R134a systems a retrofilled system can only be filled to 90% of its capacity when compared to if filled with R12. Underfilling can cause damage to the compressor (possibly due to a lack of lubrication) where overfilling can cause seals to blow.

You can get around the above by filling with R12 which will arguably give the best performance (and is also illegal), run a conversion gas (where the cooling effect is diminished) or R134a using the above steps (almost as good as when the car was on R134a).

I shall dig up some links where I found the above information.

 

[tartan_rob]

I'll try the conversion kit and see how I get on, will report back.

Car almost done so gagging to finish it off.....and have a seat in the nice new seats

 

[kdp]

One more thing to add to what has already been said, is that unless you still have a little gas still in the system then the positive pressure should prevent the ingress of moisture. If on the other hand it's empty and has been for a while then moisture will have entered the system and it will probably need a replacement drier. A vacuum down will remove moisture, but it's unlikely to resurrect a saturated drier I wouldn't have thought.