For you guys who have done the conversion, is it necessary to
change any O rings or just follow kit instructions and change the
refrigerant?
Tony Russell
VA Bch VA
90 Sov 39K–
Navion
Virginia Beach, VA, United States
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It used to be said you had to change the O-rings and the hoses and the
compressor seals and the expansion valve, but that was a long time ago. Now
none of that is needed - if it ever was. So don’t change a thing. If the
worst comes to the worst and an O-ring leaks, you are not out much. Odds are
nothing will leak.
Dave-----Original Message-----
From: owner-xj40@jag-lovers.org [mailto:owner-xj40@jag-lovers.org] On Behalf
Of Navion
Sent: Saturday, August 07, 2004 3:32 PM
To: xj40@jag-lovers.org
Subject: [xj40] A/C conversion to R134
For you guys who have done the conversion, is it necessary to
change any O rings or just follow kit instructions and change the
refrigerant?
Navion
Virginia Beach, VA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting
services and resources including Photo Albums, Event Diary / Calendar, On
Line Books and more !
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from David Hurlston sent Sun 8 Aug 2004:
I’d recommend changing the condenser for a larger, more
efficient, parallel flow model. Otherwise, you might notice
a drop in cooling performance.
Regards
George–
The original message included these comments:
For you guys who have done the conversion, is it necessary to
change any O rings or just follow kit instructions and change the
refrigerant?
Tony Russell
–
1989 XJ-S 3.6
London, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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In reply to a message from George Bray sent Tue 10 Aug 2004:
George,
Wow! That’s a little extreme on an XJ40 isn’t it?
I converted mine last year from R12 to R134 and if there has been
any degradation in cooling performance I certainly have not noticed
it - even in the steamy heat (for the UK) we have experienced in
the past week.
I think the standard MKIV system on the XJ40 performs more than
adequately on R134 - certainly for the range of temperatures /
humidity we normally experience in the UK, global warming
notwithstanding. :-)–
The original message included these comments:
I’d recommend changing the condenser for a larger, more
efficient, parallel flow model. Otherwise, you might notice
a drop in cooling performance.
–
Bryan N ('91 Sovereign 4.0 L)
Cambridge, United Kingdom
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Bryan,
Do you remember what parts did you use for the conversion? It is good to renew the drier, of course. But what about the thermal expansion valve (CAC8169), retrofit service port adapters and O-rings? Is it necessary to renew these as well?
And do you remember is it PAO or PAG oil that should be used in the compressor? The Haynes manual says “Refit the drain plug and end-plate and add 199 cc (7 fluid ounces) of new oil of a type compatible with the type refrigerant in your system.”
This is interesting as the bolt of that end-plate requires the hard lines. However, it is possible to install a temporary spacer between the head of the bolt and the end-plate when you install the compressor back to the car.
I recently converted my '90 Sovereign to R134a, the AC not having worked since I picked up the car late last year. Though low mileage, 30 year old components are going to be tired. I assumed right up front that the compressor was shot and given how all the car’s other hoses were brittle and leaking, I saw no reason to not replace all the AC hoses. When buying a compressor, most come with a new expansion valve. It should go without saying that if you’re only wanting to do this once, do it right and make sure all the O-rings are also replace. A new drier is mandatory if you’re replacing anything else.
Flushed the evaporator and condenser, pressure tested, put it on a vacuum for 90 minutes, and filled with R134a (the volume of R134a should be approx. 75% of the R12 weight) and PAG oil (think it was either 10 or 11 oz). The system produced cold air sufficient to create condensation on the outside of the windows while idling in my garage. While I can’t say if it’s as cold as it was with R12, it’s far colder than any of my other newer cars.
Over 10 years ago I had the Jaguar dealer perform the factory retrofit procedure per the official Jaguar Technical Guide booklet ( January 1994, Publication part number JTP 425, 71 pages since it covers multiple models). They changed the compressor seal, receiver dryer, various O rings, and introduced the PAG oil. No hoses changed. Worked OK but in my opinion a bit less efficient than the R12… This summer the system failed to cool and the shop determined the compressor seal was leaking. So new compressor and expansion valve and all seems to be working OK again.