Recommissioning aircon system.

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neilxjs
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Joined: Tue Nov 08, 2005 9:50 pm

Recommissioning aircon system.

Postby neilxjs » Wed May 28, 2014 11:31 pm

I am planning to attempt to re-commission the air conditioning system on my 89 3.6 XJS. The system hasn't worked in the 14 years that I have owned the car. The plan is to fit a new GM / Harrison A6 compressor, replace the expansion valve, replace all o-rings and fit a new receiver drier compatible with non-cfc refrigerant. The condenser and cooling fan were renewed when I restored the car in 2003 in anticipation of getting the system running again but it has taken me 11 years to get round to it! :!:
What I am wondering is whether anyone here has undertaken a similar task and could offer any tips or advice. :idea: Some of the questions I have are as follows:
How likely is it that the evaporator is still intact?
How should the system be cleaned before recharging?
What refrigerant to use?
Have I overlooked anything obvious? :shock:
Any help will be much appreciated.

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poprivet

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Location: Hampshire

Re: Recommissioning aircon system.

Postby poprivet » Thu May 29, 2014 8:52 am

Someone like KWE might be the best choice to carry out the whole process. As far as I know, they still use RS24 instead of R134 which means the expansion valve may not need replacing. As well as being difficult to get to its easy to damage the evaporator changing it.

I assume the speed control on both your fans is working well and that the blend flaps and heater vacuum valve are ok.
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

neilxjs
Posts: 10
Joined: Tue Nov 08, 2005 9:50 pm

Re: Recommissioning aircon system.

Postby neilxjs » Thu May 29, 2014 7:10 pm

I would love to take it to KWE for this to sort out and if I lived on the mainland I would be there like a shot but I live in NI which would make it quite an expensive operation.
The speed control on the LH fan is defunct but will be cured by a straightforward circuit board rebuild. The vent flaps seem to be working but it's hard to tell when the cooling is not working. The heater valve works so I am assuming that the vacuum system is okay. Everything is a bit of a leap of faith but once I get the cooling sorted I can tinker with the rest of the system. I just wanted to see if anyone else on the forum had attempted to resurrect a system which had been dead for a long time so that I could assure myself that it can be done successfully.

almcl
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Re: Recommissioning aircon system.

Postby almcl » Thu May 29, 2014 7:43 pm

Before you tear it down (if it's not already too late) get a local air con firm to carry out a vacuum test. They shouldn't charge too much for this and it will prove or disprove the integrity of the system.

If it holds vacuum for half an hour, chances are the major components are still intact.
You can get a set of gauges and a vac pump and do this yourself and I've revived two systems this way but now that we can no longer purchase R134a (or R12) it's not really cost effective.

R134a, which is commonly available, works fine both Delanaire MkII and MkIII systems, I've got pictures on here (somewhere) of both systems delivering air at 4°C or less on warm (24°+C OAT) days. The trick is to get the garage to put enough in. It needs 1150gm of refrigerant (Jaguar tech service bulletin) and most of the automatic charging systems don't deliver this, although they can be made to.
Al McL
'93 XJS 4.0 - '05 X type Est 2.0D - '13 XF 2.2D Sportbrake

neilxjs
Posts: 10
Joined: Tue Nov 08, 2005 9:50 pm

Re: Recommissioning aircon system.

Postby neilxjs » Sat May 31, 2014 9:50 pm

Thanks almcl. That's useful information. I have the old compressor out but other than that the system is intact so a vacuum test should be possible if I stop end the hoses.


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