Air Conditioner being service. This technicians specializes in A/C systems.
Issue: After replacing the hoses they charged the system and the freon is holding steady in the system meaning no leaks. However when they charge the a/c the low side goes to a negative pressure and the high side goes up high. I believe it is the expansion valve what are your thoughts and if it is the expansion valve where is this valve located?

 

There is a self test that may point to something beside the expansion valve and you will be covering most if not all the components . Is the compressor clutch engaging by feeling by hand the change in compressor vibrations and is the smaller ( ? ) of the tubes going forward to the condenser getting hotter ?


The larger tube in the pic corner points forward and is on the right hand side . You have to take the pics lower edge and flip it to the top . This puts the expansion valve between the engine bulkhead and the evaporator .

https://www.jaguarforums.com/forum/x...-guide-146900/



Editing post

 

Lady Penelope, Regarding your questions: Is the compressor clutch engaging by feeling by hand the change in compressor vibrations and is the smaller ( ? ) of the tubes going forward to the condenser getting hotter? It is after shop hours now so I will ask the technicians and get back to you soonest (Tuesday). I printed out the attached information and will provide it along with the Climate Control Test and Diagnostics Video to the Technicians if they need it. Chances are they are familiar but just the same I have it now also with MUCH Thanks to you.. Again I will advise on our progress to completion. MATMD

 

They might be trying to gimmick you into an expensive repair by having a fault by pulling the clutch connector . Although they will want you to stay out of the work area as they perform the pressure gauge test , to insure you're not being ripped off I would personally observe the pressure test and you can hear a engaging compressor and a shifting RPM without putting your hand in there . If they don't let you , find another shop , it's your money . You can do a compressor clutch test yourself if you start with a system that has been sitting for a couple of hours so that the high pressure side has bleed down . As you engage the A/C switch the clutch should engage up to the point that the overpressure switch commands the clutch to disengage if it is truly the case , from there you can do the self test if the clutch stays engaged . Was there a reason why you had the hoses changed ? There are o - rings on the end of the hoses .

This is my opinion and I can be wrong

Thanks , Parker

 

### Correction ### In giving it some thought as to how the system works you could have a clogged expansion valve from the deccicant particles in the dryer coming loose and getting past the compressor to get lodged into the high side of the valve . May be possible to blow shop air into the low side to expel the clog . This would explain the vacuum on the low side for the supply of freon may be chocked off and the compressor sucking it down . Suggest see if they can blow it out before changing the expansion valve . This will require a freon evacuation and recharge to find out . Air pressure applied to the large hose fitting ( ? ) .

 

Mine was an inexpensive fix - the dryer bottle was clogged, and replaced. See my earlier post:
Replaced AC Receiver Drier

 

No Joy...The technicians reviewed the information I provided along with the Climate Control Test and Diagnostics Video and were able to ascertain that it is unfortunately the expansion valve inside the Dashboard. Unfortunately pulling the dashboard may be more than they are able to handle. I knew this before hand. I observed them Monday (2hrs), yesterday early AM..Tuesday(1.5hrs.) and finally today Wednesday (2.5hrs.) in the bay working on it. Current charges are: 2 new hoses (I authorized), their external diagnostic setup (to correlate with the on-board test indications), R-134a, 2hrs of the 6hrs at a (reduced) shop time charge (yep...I was in there helping them too...) They are sending me to another shop they coordinated with to do the heavy lifting on the expansion valve inside the Dashboard. Ok so why did I take to them and not this other shop? 1. These are my Go-2 Guys we have history, 2. Trust, they repaired two of my other three vehicles, (both Cadillacs) at an amazingly inexpensive price. 3. They were straight up with me about the expansion valve and their apprehensions of getting into tearing out the Dashboard, 4. I/We gambled on it NOT being the expansion valve, 5. They are less than 2 miles from my door. More to come until done...

 

Good to have a shop that will be straight up with you and not take advantage of you , keep patronizing them . A local X308 owner has had the reverse experience with different shops on different items . Her car is all white so she named it Freckles . Where they able to blow it out if it was clogged ? If the soldier joints on the temp bulb on the expansion valve it'self is cracked then there is no other option then to replace it . Unless someone knows a way to repair it as the evaporator is installed before removing it .

Thanks , Parker

 

I have done this repair a dozen times and I have never had to replace the expansion valve. It takes flushing/persistence and an EVACUATION machine to get all the beads out of the line from the drier to the valve. FIRST REPLACE THE DRIER.

Blow compressed air and flushing solvent back and forth in the disconnected aluminum line and EVAP core. Charge the system with refrigerant. Operate system and evacuate refrigerant if pressures are incorrect and cooling is inadequate.

Blow compressed air and flushing solvent back and forth and charge the system with refrigerant. Repeat as necessary. A few more beads will be expelled.

It is tedious but it is easier (for me) than changing the expansion valve.

bob

 

Parker, Qvhk & Bob, You Gents MAY be onto to something. Had I seen these posts before picking up the Car today at 10AM, I'd have printed out these comments/instructions and taken them back to my Auto "A/C" Technician with a new DRYER BOTTLE in hand to BEG he go the distance and do this as well (on my Dime of course). Albeit, he provided the following PANEL CODES 23, 24, 41, 42, & 45...Per Bulletin Number 14-10 page 3 of 3: "PANEL CODES" indicate:
PANEL CODE#: COMPONENT - FAULT
Panel Code 23: Refrigerant Pressure Switch - Low Gas Charge or O/C or S/C high
Panel Code 24: Face Vent Demand Potentiometer - O/C or S/C high
Panel Code 41: LH Fresh/Recirc. Motor - Flap did not reach position within 30 sec
Panel Code 42: RH Fresh/Recirc. Motor - Flap did not reach position within 30 sec
Panel Code 45: Center Vent Motor - Flap did not reach position within 30 sec

I am certain the aggregation of these Codes are pointing directly to the basic problem & fix like:"REPLACE THE DRIER - DUMMY"...of course they/we did not do that...yet. However, given these are the Panel Codes, what would you ALL conclude?
1. REPLACE THE DRIER, 2. EXPANSION VALVE --or-- 3. Something Else....?? Please bear with me... I'D lOVE A: JAGUAR MANUAL FOR DUMMIES

 

My Apologies motorcarman, I inadvertently left you out of the above message. Your info was extremely helpful and will be the way to proceed (flushing/persistence and an EVACUATION followed by Blowing compressed air and flushing solvent back and forth and charge the system with refrigerant. Repeat as necessary) after replacing the drier.

 

I would focus on the things the freon flows through first and then the items that direct the chilled air last other then to verify that you have both left and right cabin blower fans . The pressure gauges are accurate information in troubleshooting ( The freon recharge cans with the color changing vent clips that verify the final output vent temperature as a way to verify pressure gauge pressures as a direct corlination in a Carnot refrigeration cycle as you can do it without gauges ) can resolve that , the codes may not be or can be addressed later or lived with as long as the cabin cools down . The codes may have been " latched in " years ago in volitile memory ( aircraft term ) in the A/C ECU as something may have hiccuped in the past and are not an issue today . You can reset the codes and see if they show up again in a couple of weeks of present use with the panel self test . Suggest follow what Bob advised before investing in a expansion valve replacement for he obviously has more experience .

 

Any updates ?