Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
BritCarFan
Jedi Hopeful
Offline
Does anybody know the required pressure of the A/C system on my '93 XJ40?
-
Hi Guest!
If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
A/C refrigerant pressure
- Thread starter BritCarFan
- Start date
Share this page
Exotexs
Jedi Knight
Offline
I don't, but the Service Manual for your model should tell you, including any special steps to take. Jaguar A/C systems are very finicky, I would not take any chances. The Service Manual comes in a CD, for about $25. Less expensive than a rebuild! check eBay, sometimes they show up for $15.
jessebogan
Jedi Knight
Offline
The pressures are dependant on outside temp, refrigerant charge, idle speed etc.I would expect 30 to 40 psi on the low side, and 180 to 220 or so on the high side. What do you get??
OP
BritCarFan
Jedi Hopeful
Offline
I hooked up the pressure gauge to the low side and with the engine idling and the A/C at max I was reading 45 psi. According to the gauge that is right at the maximum for the system.
jessebogan
Jedi Knight
Offline
That seems high. Are the fans working? If so, I would suspect a bit of an overcharge. It would be helpful to know the high side pressure also.
OP
BritCarFan
Jedi Hopeful
Offline
It has the R134 refrigerant.
BIBBER
Jedi Knight
Offline
Ok...I know I'll open a can of worms on this comment...but I've read and heard over and over how tough recharging AC systems can be....both my 2002 SUV and my 91 Benz were blowing hot...I went out, bought a $33 recharge kit from Walmart (it came with 3 cans of R134a)....put 1 1/2 cans in both vehicles on the low side until the gauge read in the blue area....and they're both blowing ice now....maybe I got lucky but the effort took 30 minutes total and saved me $100's in service fees....
Jesse is right, the pressures depend on the outside temp. R134 runs t highe prssures than R12.
Your low pressure reading seems OK. I would think that the high side is a few pounds low.
Does your car have a sight glass? Any bubbles in it? If so, add refrigerant until the bubbles disappear. R134 systems are more sensitive to low presures than R12.
Your low pressure reading seems OK. I would think that the high side is a few pounds low.
Does your car have a sight glass? Any bubbles in it? If so, add refrigerant until the bubbles disappear. R134 systems are more sensitive to low presures than R12.