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360 AC Problem, High Low Side & Low High Side

Discussion in '360/430' started by TheRealFlyingBear, Jul 20, 2020.

  1. TheRealFlyingBear

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    Apr 27, 2020
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    Ken
    Added UV dye to the system and refilled with 500g of refrigerant per the WSM to try to find the leak. Could not find any visible evidence of a leak via UV light.

    I did a complete fill of the system to 750g, still can't find a leak. Pressures are still similar to what I was originally getting (45/150psi). Vent temp was actually pretty good at 58F in 80F ambient.

    I think it's possible that my AC Pro manifold gauge set isn't holding vacuum well, or maybe I have a leak that can't be seen externally? My AC professional thinks my thermostatic expansion valve is stuck open so I'm hoping to get his help to flush it out since others seem to have fixed their systems this way. Will also have him use his gauges and pump to see if he can detect a leak.
     
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  3. FlyingHaggisRacing

    FlyingHaggisRacing Formula 3

    Jul 2, 2013
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    I think your next step will be to swap the AC compressor before dismantling the dash to access the valve.
     
  4. TheRealFlyingBear

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    Apr 27, 2020
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    @INRange

    Getting ready to evacuate the system again and flush the system (or just reverse flush the expansion valve). Reading about flushing on the internet, some articles state that purging the system with nitrogen is required after using flush solvent. Is this necessary? Or can I just flush the system and then pull a vacuum? I was thinking of using "supercool AC fast flush" which apparently evaporates quickly and leaves no residue.
     
  5. INRange

    INRange F1 Veteran
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    Ken,

    The facts:

    -You have a leak because the freon you recovered was well below where it should be.
    -After recharging it with a UV dye you haven't been able to find a leak.
    -Putting a full charge in the system gives you a -22 degree differential which by any stretch of the imagination means the system is working. Granted it may be on the low side of the differential, that may just mean the compressor may have more miles on it if it was "rebuilt" (credit @FlyingHaggisRacing).

    Now you want to flush the system based on the thinking that the expansion valve is stuck open? Could it be partially stuck open resulting in lower pressures......sure but that is not the problem at hand. The problem is the leak. Most clients living with a 22 degree differential would consider it a success. To answer your question it is not necessary to flush the system with nitrogen but unless you are dead set on disconnecting the compressor and flushing the lines....I would find the leak.

    Does your AC friend have one of these? I personally have never had any success with UV dye, propane (really bad idea) or any of the DIY methods unless the leak was large. If that was the case....soapy water would find the leak. Find someone who has a professional grade detector and find the leak. My guess it is either the compressor itself or the line connections on the back of it.


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  6. mike32

    mike32 F1 Rookie

    May 13, 2016
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    If you have a small leak you should see signs of an oil leak or oil drip. The gas carries oil with it through the system, so if gas is leaking you should see an oil presence. As it is holding a vac for a while the compressor seal is a good point to start, as the seal wears the seal spring should adjust the rotating section to maintain contact with the fixed face of the seal- If the rubber seat or O ring ( depends on design) is too tight then the spring cannot maintain the seal face pressure to achieve the rotating seal
     
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  8. TheRealFlyingBear

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    Apr 27, 2020
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    Thanks again for the continued discussion.

    I found the low side Schrader valve is leaking. Every time I remove the plastic cap, it releases refrigerant and hisses. Not sure that leak is enough to cause the recovered refrigerant to be at 1lb instead of a full 1.5lb or 750g.

    I have an electronic leak detector from Amazon and it doesn't detect any leaks in the system. Whether or not a more expensive detector would detect leaks, not sure. I will ask the mobile AC guy next week if he has a better detector when he comes by to evacuate the system.

    Would a small leak also cause low pressures? I guess it's possible? I need to redo the vacuum test on the system. I found that my manifold hoses weren't tight enough and were leaking under vacuum by themselves.

    I'm also researching how difficult it is to replace the expansion valve on a 360. Has anyone here done it? The WSM recommends removing the entire evaporator assembly. I hope this isn't necessary. If it is I probably try flushing first before replacing.


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  9. mike32

    mike32 F1 Rookie

    May 13, 2016
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    The electronic ones are rubbish, the old propane torch detector are the best still
     
  10. Scottslaw

    Scottslaw Karting
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    Here is my very uneducated 2 cents. My recent addition arrived blowing ambient air only. Replaced the compressor clutch and at that point the compressor started working like it should, but still no cold air. Took it to a shop that specializes in automotive AC repair. They said that our cars are very sensitive to the proper amount of refrigerant, and that for this reason you can't use those auto parts chain store cans. Too much and cut-off switch kicks in to save the compressor, and too little and the cut-off switch kicks in as well.

    When they charged my system it held pressure but had "wacky" high and low side readings (sorry I didn't get more specific information than this!), and still no cold air. They told me that based on these symptoms and some other observations, they were 99% sure my compressor had a bad "compressor control valve" and that these valves are replaceable and widely available and used on many different compressors since its a delphi unit. So they evacuated the system for me, told me to go buy one and install it (50 bucks on ebay: https://www.ebay.com/itm/A-C-Compressor-Control-Valve-for-Ferrari-California-Enzo-F430-NEW/113291597458?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649), and then bring it in for a re-charge. Just ordered the part and will try and replace it, and then report back. If that doesn't work I'll spring for a new compressor but for 50 bucks I thought it worthwhile to give this a shot. Just sharing my experience so far...good luck!
     
  11. INRange

    INRange F1 Veteran
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    One of the 134a coupling valves is certainly a possible candidate for the leak. It won't change the pressures very much unless it is a sizable leak. Plus....when you have the gauges attached.....it is sealed which means when you pulled a vacuum and it still leaked down.....so it wasn't one of the 134a coupling valves that was leaking. I still think the problem is at the compressor.

    Did your AC guy's gauges read the same as yours? I have three sets of gauges and they never agree with each other. That's why it is far more important to have an accurate refrigerant scale to weigh the charge in.

    I don't have a 360 but perhaps another member could post their pressures so that you have a real comparison to work with. What would be ideal is:

    -Outside temp
    -RPM
    -High side reading
    -Low side reading
    -Vent temp

    In regards to finding the leak......despite what people think.....the pros use electronic sniffers that run $200-300. The ones you can buy on ebay are useless. There are plenty of people who think propane is also great as a refrigerant. Leaks would be easy to find all you need is a match and a paid up insurance policy.;)
     
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  13. TheRealFlyingBear

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    Great suggestion, thank you. One of the symptoms of a faulty compressor control valve is high, low side pressures. This might be a low cost, easy thing to try before trying to flush or replace the expansion valve. I don't see any diagrams on the typical Ferrari pages (Ricambi) for how to access the control valve, but I assume it's somewhere on the compressor where that 2-wire connector runs. Hopefully it's not a snap ring holding it in place, I hate dealing with snap rings.

    Scott, personally I don't think there's anything wrong with filling from small cans of R134a. Just an accurate scale and it's easy to be accurate within +/- 5 to 10 grams. The process isn't really different than filling from a large 30lb tank, just a smaller container and it might be necessary to swap the bottle once or twice. If the tech knows that they're doing, swapping bottles doesn't cause any problems.

    My car is in at a local body shop getting the front resprayed (car in front of me drove off the road). AC work is on pause for a week or so. I will have my mobile AC guy use his gauges and fancy leak detector on the car when it's back sometime next week. There's no visible oil or refrigerant leaking, so if there is a leak it's small.

    Earlier today, I talked to the shop that replaced the compressor 2 years ago. Their normal process is to drain the system, pull vacuum, remove the old compressor, fill new compressor with oil, install new dryer, install new compressor and refill refrigerant. I was surprised to hear that they do not flush the condenser or evaporator to remove old oil. From what I've read from forums, this potentially makes the system "over filled" with oil. However, doesn't seem to be a concern in practice?
     
  14. INRange

    INRange F1 Veteran
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    Huh? Normally the compressor company will not warranty the compressor unless the system has been flushed. If the first compressor disintegrated where did they think that stuff went? Did they record the pressures after they installed the new compressor?
     
  15. TheRealFlyingBear

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    Watching this video, they show very similar pressure readings to my car before replacing the control valve (50/150). I think I'll give this a shot as well next week! Thanks again for the suggestion and sharing the product link.

     
  16. TheRealFlyingBear

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    I didn't ask if they had pressure readings after installing the rebuilt compressor. They said the old one was leaking refrigerant, but had not failed in a way that needed the system to be flushed. Seems odd to me though. I thought normal practice was to flush the system?
     
  17. TheRealFlyingBear

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    Apr 27, 2020
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    Car's back from the body shop and the paint looks amazing. No more rock chips!

    I'll be continuing the AC work tomorrow after I receive my Blue Nylog from Amazon. Doing some research, it's apparent that PAG oil isn't the best choice for lubricating o-rings since it attracts water and can lead to corrosion. I was surprised to find this since I've read many other articles suggesting to just use the AC oil to lubricate o-rings. What are you guys using?

    I went under the car and saw the compressor control valve is very easy to replace. The clip is facing straight toward the ground so you could potentially remove the valve without removing the compressor from the car. I will be removing the entire thing from the car to properly drain the compressor and refill it with PAG 150. Come to think of it, if you're interested in draining the oil from your compressor this might be the easiest way to do it.




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  18. Scottslaw

    Scottslaw Karting
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    no problem. By the way, I just did it and I now have cold air! Very easy. Just remove the clip, lever out the valve with a screw driver and then replace. It will be a tight fit. I had to use large jaw pliers to push it in. By the way, no oil came out of mine. Make sure you have no refrigerant in the system and that you depress the two Schrader valves up front to release any residual pressure before removing.
     
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  19. FlyingHaggisRacing

    FlyingHaggisRacing Formula 3

    Jul 2, 2013
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    Can you share where did you buy the replacement valve ?
     
  20. Scottslaw

    Scottslaw Karting
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    eBay. Posted the link a few lists above.
     
  21. TheRealFlyingBear

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    Apr 27, 2020
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    Worked on the AC all day today. Unfortunately, I still haven't found the leak. Given the low amount of oil I found in the compressor and the color, I believe the compressor may be leaking. Here's what was done today:
    1. Replaced all o-rings for pipes going to the condenser. Found one of the fittings was badly rusted and the oring was dirty.
    2. Repaced orings on lines going to and from the compressor
    3. Replaced all orings in the dryer/filter area
    4. Replaced orings going to evaporator
    5. Removed compressor from the car and drained it. Only 1.6 fl oz came out, it's a weird orange/brown color.
    6. Filled 5.5 fl oz into compressor, re-assembled
    I chose not to flush the condenser and evaporator. Worried about causing more harm than good and I don't see to have blockages anywhere. Instead, I assumed there's approximately 3.5 to 4 fl-oz in the lines, condenser and evaporator. I know, not the best way to do things, but that's the call I made.

    Anyway, after reassembling everything I did a vacuum test and I am sad to say that vacuum still does not hold. I can pull down to -29/30 inhg but it doesn't hold. I may try to get a rebuild/new compressor next. Condensers are also on sale for $500 at Scuderia. Thoughts?
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  22. TheRealFlyingBear

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    Apr 27, 2020
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    I'm tired of trying to find the leak. New condenser ordered. New compressor will be ordered tomorrow from polar bear once I figure out which model is correct/best for the 360. If replacing these doesn't fix it then I guess I'll head to Roselli's for help.
     
  23. TheRealFlyingBear

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    Apr 27, 2020
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    As I was searching for a good used return hose to pair with the new condenser, I think I actually found the cause of my leak.

    Earlier today I noticed the fitting for my upper metal pipe going to the condenser was oval shaped instead of round. I thought that was odd, but the mating female port on the condenser was also oval shaped so I didn't think much of it. This connection was also pretty badly rusted and was very hard to remove. Looking at "good condition" used parts I saw in photos that the metal pipe and fitting is supposed to be round. I believe this is the source of my leak since the two oval shapes are not perfectly identical and the o-ring is probably having a hard time filling the gaps. I'm guessing the metal pipe and fitting got crushed by a technician trying to use vice grips on the nuts.

    Anyway, I am going to try a couple things to see test if this is the leak point. 1) larger o-ring. 2) nylog

    At any rate, the new condenser and pipe are on the way.
     
  24. TheRealFlyingBear

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    Apr 27, 2020
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  25. TheRealFlyingBear

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    New inlet pipe arrived today for the condenser. The normal round shape is 11.7mm in diameter. My damaged piece is an 11x12mm oval. Unfortunately the condenser fitting is also smashed to this 11x12mm shape so I can not assemble the new pipe to the old condenser to see if that fixes the leak. New condenser should be here soon and I'm waiting to hear back from Polar about which "new aftermarket" compressor I should purchase. They offer various options and it's not clear which one is the best/correct one.

    Here are the two options I found on their page.
    CO 7531NEW_AM
    CO 1290NEW_AM
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  26. BrettC

    BrettC Formula 3

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    Too bad, looks like someone hacked that pipe. Keep us posted!
     
  27. TheRealFlyingBear

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    Apr 27, 2020
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    Well, my system was holding vacuum at -10 in-hg, but not -30. I decided to fill with refrigerant to see if I could detect a leak and there's nothing so far. The system pressures are also better than before. Approx 45/200 (low/high) in 85F environment. Vent temperatures are also around 47-50F, which is cooler than before.

    I'm calling it a win for now and will keep checking for leaks periodically. Full rebuild and new condenser will be saved for another time.
     
  28. ItalGerBrit

    ItalGerBrit Formula Junior

    Mar 15, 2016
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    Swamp
    Late to this party but if you are not holding the vacuum you have not yet found the leak or leaks. Can easily have several leaks. They can very hard to find and throwing parts is usually hit or miss and more frequently miss. Some of your "fixes" might add new sources of leaks. I have had better luck with the sniffer than the dye but use both.
     

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