I don't want to blow seals out that were fine. I agree to receive emails from the site. Here (at our facility) we use refrigerant to find leaks. Once the suction line iscompletelyopen, open the liquid service valve,re installthe valve cores and remove the vacuum gauge and core tools. Cookie Policy - I appreciate your advice. Questions About Becoming A Professional Member? If the system has a leak the vacuum gauge will continue to rise until atmospheric pressure has been reached. Many assume once refrigerant is lost, dye cannot be seen. All on separate occasions, of course!!! Think I'll just do rear ac block off. On third can, When compressor was not spinning, high dropped all the way down almost to vacuum. Speaking of leak points, when I disconnected my hose I heard a hissing from the low side and there was fluid effervescing in and around the valve. A non-condensable gas will remain a vapor in the condenser. The #1 question asked by NEW MEMBERS. When a typical system is installed and/or serviced, air and moisture enter the system. Non-condensable gases (in most cases surrounding ambient air), are not able to condense inside the air conditioning condenser, unlike refrigerant gases like R-134a or R-1234yf. 2018 Ram 1500 4X4 Crew Cab Bighorn (5.7 Hemi). I found a leak midway back on the van, on the High/Liquid line, also. (Note: a system that continues to level off at 3500-4500 microns may have turned system moisture to ice. Did you use the old two wrench method for tightening the fittings? Read our Privacy Policy for more info. Performing this test will again pick up some additional moisture that will not have to be removed during the evacuation process. replacement. It was already boogered inside on the threads there and at top of the valve. If the system is drying out you will notice that deeper levels of vacuum are quickly achieved indicating progress in the job of dehydration. If a leak is indicated, it must be repaired before the evacuation can be completed. However if the system is vacuum tight but still contains moisture the rise will level off when the vapor pressure equalizes in the system typically between 20,000 and 25,000 microns between 72 and 80 F. At that point that vacuum reading will become stable. Honestly, if you're pulling cores and using anything better than 1/4" hoses, you should get under 5k in 15mins or less on even a 5cfm pump, in my experience. JavaScript is disabled. Pull a vacuum until a level of 1000 microns is reached, (if using large diameter hoses and core tools, evacuation of the line set and evaporator coil will take less than 15 minutes for a typical residential system of up to 5 tons). It broke inside the fitting but I managed to use a screw extractor to get the valve out. try turning the compressor over a half turn,ive had them do that,they leak somehow through the compressor.Weird but it has happened to me,turned the compressor over a bit and it was ok. Also the seals may not be "puffed" up to give a good seal,have had lots that sealed undr vaccuum and leaked when pressurized?,The new cars with all the aluminum pipes are bad for that,if the pipe is bent a bit out of shape they will leak too. I stopped using my manifolds to pull a vacuum about a year ago. Refrigerant oil as a fluid is like water; apply gas under pressure and a fluid absorbs gas. Non-condensable gases have a serious impact on system performance, operating conditions, and lifetime of an air conditioning system. failure, decreased capacity and increased compressor wear and potential Within narrow limits, the purpose of the vacuum ballast is to prevent water vapor from condensing in the pump during the discharge stroke of action. (Note: When the vacuum gauge indicates "high pressure" you are above 20,000 microns but still in negative pressure.) I was determined not to take it to an AC shop and figure it all out for myself. 2016 GC Crew Plus - 3.6L - Bright White - 160,000 km. systems, (like R410a) causing premature failure of the oil. If the leak rate has not decreased, two things may be happening: 1) The system is still contaminated with moisture. It will not flow to the condenser outlet like liquid refrigerant does after its been condensed, but instead it will remain trapped inside the condenser tubing. If you suspect the TEV is the issue consider first it might be an o-ring seal issue, inspect: I'm running in circles on this and will need to return to a pressure test. You may just have a leak in your manifold gauge/hoses setup. Ac compressors come shipped with oil in them. Break the vacuum with nitrogen to that equivalent to atmospheric pressure (760,000 microns) then purge nitrogen through the system at 1-3 psig. A high quality, high resolution vacuum gauge like the ones found on this page Vacuum Measurement, can indicate a leak much faster than a pressure gauge due to the sensitivity of the instrument. But when we attach our vacuum to get it down to below 500 microns, it won't vacuum. Evacuation is a two step process of There's a difference. The price range could be $85.00 to $300.00 dollars to evacuate and recharge a system. Privacy Statement - To properly perform evacuation also consider the RapidEvac kit from TruTech Tools. Both of these problems result in intermittent cooling or no cooling at all. With a system working under these conditions, pressures will get beyond a default safe point of some refrigerant control devices in the system, probably shutting down the system to prevent any irreversible damage, like compressor seized up or a hose explosion. They all had a tag on them telling you not to drain the oil out of them. google_ad_client = "pub-8306900413359372"; The hoses all look great, and makes me think that someone replaced them as I found a 134a fitting on the low pressure side hidden under the pressure switch. Design by Final Web Design, The amount of refrigerant needed for properly charging the system according to manufacturer specifications, The type of refrigerant needed for properly charging the system according to manufacturer specifications (R-134a or R-1234yf). While at first it may seem counter intuitive to use large diameter hoses the value rapidly becomes apparent after starting the evacuation. The pumps ability to clean the system is directly related to its ability to reduce pressure, create a vacuum, low enough to boil off all the contaminating moisture. So, I got a a hold of an a/c leak detector (sniffer). Sludge and solids can be removed only by correct filtration (Air conditioning system flush). /* 728x90, created 4/10/11 */ Could it have gotten a bunch of water in it somehow after the refrigerant leaked out? Clean vac oil, nylog, etc. Low pressure was high. system has been opened to atmosphere is critical to proper operation of Removing air and/or other non-condensable gases from a system with a vacuum pump is called degassing a system. Well I got the o ring I was looking for, & got everything tightened back up. This will push out the moisture vapors with out dropping them out into the system in liquid form. A vacuum gauge is used to determine the level of atmosphere (degassing and dehydration) in the system. The gauges keep showing OL microns, over load, more than it can read. I can unsubscribe anytime to withdraw my consent. Copyright 2022, All Rights Reserved, Auto A/C Repair LLC. The conductance speed of 1/4" hose is so small it should never be used for evacuation. I'd put in a can of oil first and let it pull through the system. One of the most important things you can do is to always nitrogen sweep or purge a system before performing an evacuation. Terms of Service - To preform this procedure, reduce the system pressure to between 1000 and 2500 microns. A perfect vacuum remains long after the vacuum pump is shut off to allow recharging a repaired system. If your pump is equipped with a gas ballast, open the ballast until a level of 10,000 microns is reached. (something that gives stability)The ballast, when it is open introduces free air into the pump during the discharge stroke to keep this moisture in equilibrium. The gas ballast is only effective in removing small amounts of moisture, so a very wet system will require frequent oil changes if you want to make fast work of getting the job done. Im hoping its not the rear evaporator. After the second standing test, allow the vacuum pump to run until the system is preferably below 200 microns. For the evacuation and test I left my equipment on overnight- I have no ability to read what the pressure is otherwise. I have pulled down a 330lb circuit for a screw chiller in 8 hours using a 7cfm pump. BluVac pro indicates vacuum level higher than 25,000 microns incase you were wondering lol. Discharge pressure and compressor temperature will go up which can lead to increased lubricant breakdown and shorter compressor lifetime. In other words, connect to as many places as you can on the system but eliminate unneeded hoses or fittings. Use a calibrated flow meter to avoid using excess nitrogen. Installing the dryer inside near the evaporator will better protect the metering device, assure visually that 100% liquid is present, and prevent the dryer from rusting prematurely. But I hate to buy a new dryer and then figure I still have charging issues. Switched to a different set of gauges and everything went to plan. No refrigerant with dye injected into an empty system is necessary. On third can, I noticed exhaust seemed to be smoking. It was reading about 25 low & 150 high, while running compressor. Tubing must be kept clean and dry through the entire installation, moisture dirt and other contaminates can compromise system operation and significantly increase the time required for evacuation. Because of the resolution of the BluVac, we highly recommend you use vacuum rated core tools and hoses. 1/2" hoses will decrease the time required for evacuation by a factor of 16 times over the typical 1/4" hoses used by most of the industry. Test posts are permitted. After the second drop test check the condition of the vacuum pump oil. Do Not Sell My Personal Information -, By logging into your account, you agree to our, Location: Deep in the Pisgah National Forest. A good quality pump will easily achieve levels or below 50 microns. 100% UA the only HVAC union! We left it for 2 hours and came back, still says OL. Im not an AC guy, but what kind of issues does moisture in the system cause? After the lines and the various components have been installed, it is necessary to make sure that there is flow through the entire system by purging with a dry gas such as dry nitrogen from the liquid line to the suction side of the system. This means push the nitrogen through the system, one side to the next WITHOUT significantly raising the system pressure. The best thing to do is eliminate fittings all together. You will see the microns dropping rapidly within 5 minutes. Having the ballast open during the initial pull down of a wet system will help to prevent condensation within the pump. I had this happen to me once where one of the hoses had a leak at the connector crimp. Where high temperatures are frequent, non condensibles combined with moisture will also cause oil Those all seem tight. With a vacuum pump connected to both, low and high air conditioning system sides pull a deep vacuum for at least 5-45 minutes. When you start seeing it leak see where it is leaking from. Oil that is milky contains moisture and will not allow a finishing vacuum to be achieved due to the increase of vapor pressure and loss of sealing caused by the moisture in the oil. Water can only be removed from a system in vapor form. The black band represents vacuum from zero to -30 in hg. Anyone else ever run into this? Look up triple evacuation method. I did do an evaporator and expansion valve on my 06. I think triple evacuating is often overlooked. For a better experience, please enable JavaScript in your browser before proceeding. If servicing and existing installation, break the vacuum with the required system refrigerant prior to removing the core tools then continue the commissioning procedure as required by the manufacture. Removal of both is typically referred to as evacuation. If I can't, I know I need a nitro purge, and keep doing so (pull down until it stalls, break w/ nitro & purge) until that happens. At this point your system is holding pressure but the compressor isnt working. We never hope to find leaks while in a vacuum. VACUUM RIG, (1) Refrigeration Air Conditioning Technology 5th Edition Copyright 2005, (2) Review of Vacuum for Service Engineers 1988. Again, pulled vacuum. A vacuum of about 500 microns or 29.92 hg gauge pressure is needed for removing any moisture that may have entered the system along with the non-condensable gases while it was open. RULES for AOP - Owner Assistance and Contractors, Energy Efficiency and Building Performance Discussion NEW, Carnak Zone/Locked Areas - For Professional Member Only, How To Become a Pro and Rules For Pro Members, Pro Forum: Refrigerants and EPA regulations **NEW, Pro Forum: Residential Refrigeration and Appliances **NEW, Pro Forum: Equipment Recalls and Bulletins **NEW, Pro's Forum: Building Science Discussions, Educational Forums - Open for all in the industry, Welcome to HVAC-Talk's Educational Forums, How to Submit Links, Articles and Quiz Questions, Frequently Asked Questions About Submissions, Physics, Thermodynamics, Fluid Flow and Combustion, Educational, Training & Reference Information, Manufacturer's Technical Information Links, Electrical Theory, Circuits and Electronics, HVACR Equipment, Components & Accessories, Accessories Humidifiers, Air Cleaners, HRUs, Fans, Filters, etc. Not really worth the effort on small splits though IMO. It wont hold pressure for long. Moisture refrigerant and mineral oils form acids that will You could charge it with 3 lbs, and a can of UV dye. Hook up an additional vacuum pump if you have it. I put 60psi in (Which, btw stayed 60psi for 10 or so minutes or more until I let it out) This is the driest air I could get out of my desicant filter. Maybe it was just whoever made the ones you bought were different. If marked progress is not achieved during this process, repeat the nitrogen purge to remove liquid moisture that may exist. Rennlist Forum Glitches - post them here. Eliminates so many headaches. If the pump will still not achieve a deep vacuum, it may be time for replacement or service. BTW, I would never use a rebuilt. I'm not a big fan of dye. If your pump cannot achieve 100 microns or less, change the oil with a high quality, low vapor pressure oil like Appion Tezom. The last few compressors Ive bought, all Sanden style, came with the proper oil in them. an air conditioning system. Do Not Sell My Personal Information -, By logging into your account, you agree to our. contaminate line sets. What's the worst that can happen? Yeahmaybe. Thanks for the input so far. With two cans in. google_ad_height = 90; There is not better place for the working men than the union! You can also get an ultrasonic leak detector but that doesn't sound particularly useful with something like this.