My 1998 XK8 blew relatively cold air yesterday morning, yesterday afternoon just hot air. I found a code that indicated it was low on charge. It had not been serviced in the 4 or so years I have owned it and don't know if it ever has been. I took it to a shop who told me the high pressure port was leaking. It appears that the port is screwed into the dryer and may be replaceable. Anyone know if that is a possibility. If so where could I find one? If not, does the port come with a new dryer? I'm skeptical of the shop I took it to. They had already evacuated the system before I saw it, so I didn't see any leak. They told me I needed a new hose for the pressure port problem, but Jaguar only sold hoses in pairs to the tune of $600 plus labor. If the port was leaking would there be some visible evidence, oil or whatever? I had taken the cap off the port before taking it in and it looked pretty clean.

Just as a side note, for the last 2 years the air distribution system has not been working very well. I hear the fan running strong but very little air out of the vents. Sometimes selecting a different button to change where the air goes makes a small difference or toggling the recirc button. The air has always been cool though until yesterday.

Sorry I still can't figure out how to manage the picture size in the post.
(I just found the dryer available from a couple of sources and it appears the port comes mounted on it)

 

I just replaced mine yesterday. They are available on Ebay, and other places. Part number for the one on the Receiver/Dryer is MHD7372AA, and the one for the Low Pressure side, should you need it, is MHD7372BA.

 

Is it just the schrader valve that's leaking? Usually the valve core can be unscrewed with a special valve core tool and a new replacement screwed in. I don't know what type exactly but Amazon sells assortment kits such as for only $12. My 2000 xj8 has a slightly different design.

 

Most do have a replaceable Schroeder valves, but the early XK8's with the above pictured valve are not replaceable- have to change out the entire fitting.

 

Most of the originals have a plastic ball to seal the port.
SOME replacements have threaded valve inserts.

bob

 

This P/N is exactly what I needed. I took the lines off the dryer to see if the pictures of an aftermarket replacement dryer matched. I'm wondering if I should change the dryer anyway since the system has been opened and I can get the aftermarket for about $40 that comes with the valve and gaskets. I'm seeing an OEM dryer for about $113.
Thanks

 

My 2c would be to replace the dryer if the system has been opened. I got the OEM replacement from the dealer last year for £46 ($58) so you might check with yours. Came with port (and cap) but no O rings for in/out connectors.

 

I replaced the high pressure port and had the system recharged, but no joy. I think I know more about it than the shop so I took the car home. I checked the control panel codes again and it had code 23 which is "Refrigerant dual pressure switch circuit fault". This code was beeping, I also had code 11 which is "In-car temperature sensing circuit fault" but it was not beeping. I found if the code isn't beeping it is an old code and would clear with a code reset which it did. I would like to try to verify the pressure switch is the issue without first having to evacuate and then recharge the system again. Looking at the air conditioning compressor clutch relay, with the relay removed I have ~12VDC on pins 3 and 1 The power output of the relay, pin 5, goes to the compressor clutch and also the air conditioning control module. The other side of the relay coil goes to the engine control module which must supply a ground to energize the relay. I'm guessing I can jump pins 3 and 5 of the relay to see if the compressor kicks on. My only concern is not to do damage to the air conditioning control module. I'm assuming this just tells the control module that the compressor is on (or should be) and it won't hurt anything, but wonder if anyone knows for sure. I don't want to cause damage. I'm already breaking off brittle connector locking tabs when I try to disconnect connectors.
Should all the switches on the pressure switch be closed under normal system pressure? Is it a safe assumption that if the pressure switch is bad the system should work if I jumper the pressure switch pins?
Thanks

Follow up. I jumpered the relay and the compressor kicked on. It still did not blow cold air. I had a partial can of freon and attached it to the low port, jumpered the relay to engage the compressor clutch and I think it got a little cooler. I'm thinking this is telling me there is still a leak somewhere in the system or it wasn't serviced properly at the shop.

 

Same issue mechanic over charged the system and blew out the valve on the high pressure side. The ball seat went bad - My mechanic used a bolt to close it off as a temporary fix and then recharged the system slowly. Now we need the correct valve. MHD7372AA did not seem to be the correct one.