How tight should a Schrader valve be? HVAC repairs cost around $350, but you may pay more if theres damage due to negligence or lack of HVAC maintenance. Presta valves, on the other hand, are usually found in road bikes. Some condensers , evaporators , lines , etc. But if you approach a bike store, itll cost you $20-$35 to replace it. 1999 Jeep Cherokee 4.0L electrical problems. Valve leakage occurs mostly with the valve core. Inflate the tube, then immerse it in water. Schrader valves measure 8mm in diameter while Presta valves measure 6mm in diameter. Doorman and others make a valve removal tool that comes with both high low PSI fittings. Loose Valve Core 2. Are all Schrader valves the same? It was later patented in the U.S. in 1893. The valve core and pin or spring size on refrigeration Schrader valves are generally the same, which makes it easier for a professional to service them using a Schrader removal tool. The valve core leaking is an easy fix. The most common issue that would cause a Schrader valve to become leaky is when debris gets stuck in it or when the valve's rubber o-ring deteriorates. https://www.trutechtools.com/?aff=43 Use our Promo Code: \"acservicetech\" for 8% off your order!Supervision is needed by a licensed HVAC Tech while doing this as Experience and Apprenticeship garners Wisdom and Safety.All of the ACSERVICETECH Playlists- https://www.youtube.com/channel/UCOZR-1IqsAer9wzlvFgb4mA/playlists?view_as=publicIf you want to support the ACSERVICETECH Channel and receive more HVAC content, check out www.Patreon.com/acservicetechACSERVICETECH is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.You can enter Amazon through this http://amzn.to/2aenwTqThe above link happens to be the Gauge Set that I use in my refrigerant videos but you can search from there.Here is a link to the UEI DL389 Multimeter used in the video http://amzn.to/2xAdaJfHere is the link to the Fieldpiece SDMN6 Dual Pressure Testing Manometer with Pump-http://amzn.to/2jyK5KaHere is a link for the Supco Magnet Jumpers http://amzn.to/2gS4h6zHere is a link to Refrigerant hoses with valves used in the videos http://amzn.to/2aBumVI Here is the Link for the Yellow Jacket Refrigerant Manifold Gauge Set used in the videos http://amzn.to/2aenwTqHere is a link to the Digital Refrigerant Scale used in the videohttp://amzn.to/2b9oXYlHere is a link to the Imperial 535-C Kwik Charge Vaporizer for Charging Refrigerant- http://amzn.to/2oge0u9Here is a link to the thermostat 3/32 screwdriver -- http://amzn.to/2hxt7uKHere is a link to the C\u0026D core removal tool http://amzn.to/2bFpobQHere is a link to the JB 6 CFM Vacuum Pump http://amzn.to/2nqbvo8Here is a link to the JB Platinum 5 CFM Vacuum Pump with Valve http://amzn.to/2mGKcShHere is a link to 1 gallon of JB Vacuum Pump Oil http://amzn.to/2mGrlXyHere is a link to the Supco Vacuum Micron Gauge http://amzn.to/2bH98bOHere is a link to the 1/4\" by 1/4\" female coupler from Supco - http://amzn.to/2kFrbU9Here is a link to the Hilmor 4 port Aluminum Manifold Gauge Set- http://amzn.to/2m4QLikHere is a link to the Supco core removal tool http://amzn.to/2brEJcoHere is a link the Nitrogen Regulator http://amzn.to/2bXdR5fHere is a link to the Nitrogen Flow Meter http://amzn.to/2brvoBgHere is a link to the General Tools digital Psychrometer http://amzn.to/2cSHsi1Here is a link to the Amprobe Digital Psychrometer http://amzn.to/2d7cGkWHere is a link to the Fieldpiece SDP2 Digital Psychrometer- http://amzn.to/2nniMVRHere is the UEI Digital Manometer used in the videos http://amzn.to/2c1XkiTHere is the link for the Ratcheting Service Wrench http://amzn.to/2dGV4NhHere is a link to the Appion G5 Twin Recovery Pump http://amzn.to/2dGSEyrHere is a link for RectorSeal Bubble Gas Leak Detector http://amzn.to/2ckWACnHere is a link to the air acetylene torch setup- http://amzn.to/2aQalsb Here is a link to the Malco Snap Lock Punch http://amzn.to/2cY53AgHere is a link to the Wiss 3 Pack Tin Snips http://amzn.to/2bHWhWOHere is a link to the Wiss 5 Blade Crimper http://amzn.to/2bwTlsWHere is a link to the Wiss Hand Seamers http://amzn.to/2dRk83vHere is the link for the Hitachi Lithium Ion Drill and Flashlight kit http://amzn.to/2dzNgkLHere is the link for the Irwin Wire Stripper/Cutter/Crimper http://amzn.to/2dGTj2VHere is the link for the Hilmor 12\" folding tool http://amzn.to/2d9VTPRHere is the link for the Malco 3\" Blade Combination Snips http://amzn.to/2dz7EjcThank You, ACSERVICETECH Close the valve, this will push down the pin to piece there can. You'll then untighten and extract the old core before replacing it with a new one, and then tighten it up again. This leads you to think that your inner tube might have a puncture, whereas in reality, air may be escaping from the valve itself. First and foremost, keep the Schrader valves on your air conditioner clean. As an Amazon Associate I earn from qualifying purchases. Presta valves The Schrader valve's core is made primarily of brass. When you get down to specific small items like these, I doubt aftermarket parts are available. Instead, the issue is the pump that is wrongly fitted. "text": "Some Schrader valves can be tightened and this might solve the problem. Just ensure that you tighten it all the way to avoid any air leakage. If the stem is clogged, remove it and try unclogging it with a pick tool or your sharp fingernail. The first thing you should do is unscrew the cap on top of the valve and see if it there's any debris in there such as dirt or grit. The same goes when . Then you should put on a new cap and tighten it to the manufacturers specs. This tool tightens not only Schrader valves but also Presta valves. While the valve stem can also be damaged by rust, rust also clogs it. If there are numerous bubbles, it indicates multiple punctures, which means your tube is old. Slender valves usually have a stem cap that keeps dirt out of the core area. After doing some diagnostics, I detected audibly a hissing sound coming from the low input port, leading me to believe the schrader valve is leaking. "If using grease, you need to take the top cap off the pump to expose the plunger. You read that right. Once replaced, ensure that the vacuum holds on the laking cap, before wasting money on the refrigerant. Schrader valves might be more robust than Presta valves, but that doesnt make them leak-proof. When done, close up the valve and remove the tool. Then, using a spray bottle or a bottle with a soap and water mixture pour it on top of the valve. After doing some diagnostics, I detected audibly a hissing sound coming from the low input port, leading me to believe the schrader valve is leaking. Heres a guide on how to fix a flat tire with household items. Choose a blog page for more travel inspiration and practical tips and insights: As an Amazon Associate I earn from qualifying purchases. This occurs whenever the valve protrudes away from the rim instead of being placed squarely within the rim. A professional HVAC specialist (or handy homeowner) can use a Schrader removal tool to add or remove refrigerants, for example. When servicing your unit, use a towel to wipe away dirt and grime around the area and on the valve's threads. Jan 31, 2021. Place the valve stem core removal tool into the stem and over the core. Try calling Jeep, and getting some part numbers. "@type": "FAQPage", An incorrect position of the valve can also cause leakage. They normally have ball check inside to prevent water from spraying out in the pump house. The most practical fix to a damaged core is to replace it. So you might replace the Shrader valve, or at least reseat it (that often does the job - just loosen & retighten several times). You can, however, use a screwdriver and pliers in the absence of the valve core tool, though it would be slightly uphill. If it is, the check valve is broken. BUY THE KIT ON AMAZON - LINK. If its only on the tube, it means the inner tube is punctured. (Answered With Examples), Can A BMX Bike Fit in A Car? As far as getting the right parts? If the valve core is not tight enough, you will end up with a leaky valve. A schrader valve should not leak but there are snifter valves that look simular. The standard Schrader valve length is 32mm. Do you have a tire on your car, bike, motorcycle, atv, snowblower, etc that loses air over the course of a few days? Theyre generally located on the back or inside the cover and near the AC lines. It might be time to replace the core. Keep getting leaks every 4-8 months as the pressure valve fails. This prevents the tube from leaking air. https://amzn.to/3cZwMQY 700c Tubular Tires https://amzn.to/3P8NgU9 700c Clincher Tires https://amzn.to/3MHMYnw Castelli Jacket https://amzn.to/3IX3UE8 Fizik Bike Shoes https://amzn.to/3HQgELy Castelli Jersey https://amzn.to/3625hTz Parktool multi tool https://amzn.to/3pMObjw parktool screw drivers https://amzn.to/3vO2rMw microfiber towels https://amzn.to/3HLyKON CL1 parktool Lube https://amzn.to/3KtNgw3 AWS-1 Wrench https://amzn.to/3hLEbTl Tire Levers https://amzn.to/3MxsNbK Floor pump https://amzn.to/3hLC29V Giro Agility helmet https://amzn.to/35Fox9x Gopro Hero 10 Black Here you can purchase my bike quide and you can start buying your collection of finest bikes, as well as flipping bikes for profit. Call another company. }, { Related: Why is my bike pump not working? So, if it is loose, then air will escape from the inner tube. "text": "If it is definitely the Schrader valve that is leaking, and you have an inner tube with replaceable valves, you can either tighten or replace the Schrader valve on your bike." Sometimes, there is nothing wrong with your Schrader valve or tube. The Schrader company originally produced the valve in 1891. 30 Post Likes Leaky Schrader Valve Hey guys new to the field and was on a job today where we put gauges on the system and found the systems AC charge to be empty so we proceeded to do a leak test and found the schrader was leaking. To try to fix a leaking Schrader valve, deflate the tire, unscrew the valve body with a keyed valve cap or valve tool, and examine the seat or rubber sealing ring for cuts or nicks, dust, lint, or fibers that prevent the valve from closing fully. Depending on the bike repair expert you approach, itll cost you $20-$35. Using a tube I took a little oil by capping the free end with my finger. The valve needle inside the valve stem needs to be depressed using the nail so that air can be released. I've read people do this with metal caps but I only found plastic ones for my jeep online and at my auto store. ", This mixture can be dish soap, hand soap, or car wash soap. DO THIS with NO pressure on the AC system! June 30, 2022 Admin Cycling 0 Reading: Schrader Valve Leaking: How Do I Fix It? The high-pressure side will have a similar style cap and should be labeled with an H and it'll be the same process for replacement. The Schrader valve has to be screwed all the way. This one is about how to replace the liquid line schrader valve on some Trane units. Can a Schrader valve be tightened? 3. It, however, sometimes happens when the valve is incorrectly placed or the valve core is loose. Start by connecting to which ever valve and remove inner Schrader valve it will blow valve up into tube and then shut ball cock and unscrew top tube remove bad Schrader and insert new Schrader valve and reattach tube to the tool and open ball cock lever and use the top handle to screw in new Schrader valve. (and thus the repair is affordable). One of its Kind: A Sneak Peek of Underwater Scooters. But if the cap is broken or lose, dirt will accumulate and clog the core. Remember, the valve regulates the flow of air into and out of the inner tube. You can buy Schrader core tools for different devices. But if the bubbles are around the Schrader valve, then you have a leaky valve. Presta valves, on the other hand, are usually found in road bikes. Damaged Valve 4. One way to outthink people is to make them think you think. Schrader valve components (from left to right) the valve core closed (top) and open (bottom), the order of assembly, end view of stem without core and with core (top) and stem with dust cap on (bottom). Inflate your tube and wet it with soapy water. Our discussion shows two primary sources of a leaky Schrader valve; the valve core and the valve stem. So, youve to check for cracks and slight bends as any form of damage faults the core. Its easy to confuse the issues below with leaky Schrader valves. This is a common area for the a/c system to leak, if your vehicle leaks out enough refrig Show more (Solved) Schrader Valve Leaking: How Do I Fix It? Thatll stop air leakage. These tiny parts have a big impact on your homes comfort. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Hi, I'm Dave, and I've been creating helpful travel guides and itineraries for independent travelers on Dave's Travel Pages since 2005. The Shrader valve is the definitive seal. Also, note that if the stem bends, air will escape. The caps are typically labeled with an L for low and an H for high, this is the high and lower pressure lines. The cap is the main device for sealing the ports, not the Schraeder valve. While the valve core and pin or spring size on Schrader valves used for HVAC are generally similar, the valves are not all universal and interchangeable. Locating the high and low ports on your vehicle. They have a spring-loaded, circular core that is tightened with a Schrader valve core tool. This is about how to use the Schrader Valve Removal Tool to replace a Leaky Schrader valve Without Recovering the Refrigerant Charge or Pumping Down. Like and subscribe for more videos to come and to support the channel! The shaft will be under pressure and youll feel it push back, the Schrader valve should be locked in the tip. The valve also keeps air out of the refrigerant lines in AC units. A Schrader AC valve and a tire valve are similar, but theyre not exactly the same. Schrader valves are found on most bicycles and are the type of valve used for car tires. ", #hvac #autorepair Valve Core Replacement Tool (Amazon)USA: https://amzn.to/2VQfIVlCanada: https://amzn.to/3lFgJZ9Website: http://4diyers.comPatreon: https://www.patreon.com/4diyersFacebook: https://www.facebook.com/4diyersTwitter: https://twitter.com/4DIYersInstagram: https://www.instagram.com/4diyers/Tumblr: http://4diyers.tumblr.comPintrest: https://www.pinterest.com/4diyers/Tools/Supplies Needed:-new Schrader valves and caps-valve core replacement tool-refrigerant-refrigerant recharge toolChapters:00:00 Intro00:22 Finding a Leak00:45 Specialty Tool Walkthrough03:05 Repairing the Low Pressure Port05:21 Repairing the High Pressure Port07:08 Adding Refrigerant Procedure:Ill be using a specialty tool that allows for a valve replacement while not having to evacuate the system of refrigerant, vacuuming the system after, and finally adding new refrigerant. If the air bubbles are present, confirm the source. So, youve to ask, why is my Schrader valve leaking?. Replace radiator hoses with radiator when rust is present in coolant? Turn off the incoming water supply but keep the tank valve open. When you insert your air hose fitting into the valve stem to inflate the tire, the fitting uses a tiny pin to press on that plunger to open the poppet valve. Check the pump to ensure it is well-fitted before inflating. Thus, It contributes to the overall safety and comfort of your ride. How to fix leaking air conditioning schrader valve, I've read that the cap and this ring is what provides the definitive seal, Statement from SO: June 5, 2023 Moderator Action, We are graduating the updated button styling for vote arrows, CEL 12, 21, and 55 on '94 Jeep Grand Cherokee. How to replace a leaking air conditioning Schrader valve in your vehicle. What Are AC Coils and Valves and Why Do They Matter? Alternatively, over-inflate the tube slightly and then press the center of the valve to open it up and dislodge the clog. Changing the activity type of existing activities. This is about how to use the Schrader Valve Removal Tool to replace a Leaky Schrader valve Without Recovering the Refrigerant Charge or Pumping Down. "@type": "Answer", Furthermore, I have read that instead of replacing the valve, you can simply use plumbers tape around the inside of the cap, and an "o-ring" (though where that goes I dont know). You need to tighten the valve core properly to stop air leakage. This might be the most bizarre possibility, but it often happens. It snaps on to the valve head then you connect then removal portion that has a ball-cock. (usually finger tight + 1/8 turn). Every part of your bike has its importance to the overall function of the bike. The system was low, so I purchased a can of the appropriate refrigerant, this will vary based on your vehicle. | 4K In this video I explain how to tighten the pointy pin that got loose in your shrader valve. Don't forget to subscribe to my channel for future tutorial videos and like my video if you found it helpful. The final step is somewhat tricky as well. Keep the cap on, and keep it clean to prevent wear and tear that could lead to leaks. }, { How is Canadian capital gains tax calculated when I trade exclusively in USD? Is this an indirect question or a relative clause? At night using a UV light with special safety glasses, I was able to locate the leak and this allowed me to determine whats required for a repair. ), Are Subrosa BMX Bikes Good Quality Brand? What were looking for is the valve locking onto the center stem on the valve. However, if the Schrader valve starts to leak, the inner tube wont hold air. Spray bottle. } To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Schrader valves use a shell and a pin or spring to keep air pressure in or out. "@type": "Question", I have a 98 jeep cheerokee sport. cannot be flushed because of design and flush cannot be removed easily , even with compressed air. Keep it pushed down, then screw on the locking threaded knob. Over time, the stem becomes brittle and breaks easily, resulting in air leakage. Pressure alone cannot open the valve to release air or refrigerant. The rule . Unless you're savvy with HVAC units, this is most likely a job best left to a local HVAC technician. Copyright 2017-2021 Gear For Venture | All Rights Reserved. Connect and share knowledge within a single location that is structured and easy to search. A Schrader valve is common in U.S.-manufactured air conditioner units, motor vehicles, and other powered devices. "name": "Why does my Schrader valve leak? Turn the wheels so the valves are at the top and pump up your tyres. Generally, replacing the tire valve is not expensive. "acceptedAnswer": { Need professional help with your project? Clogged Valve How can I fix the Leakage of the Schruder Valves? So if you buy a general removal tool for an air conditioner, it should fit the one in your unit. Every cyclist should Have all these ! This guide on how to troubleshoot Schrader valve core issues, what to look for, and how to fix them might save you from throwing away an inner tube when it might be saved. Get a better quality Schrader valve tube as a replacement. As mentioned above, not all HVAC Schrader valves are necessarily the same. }. There are two major types of valves used in bikes, namely: The Schrader valves core is made primarily of brass. 1. If refrigerant is leaking from your AC unit, your Schrader valve might be broken. (BMX Pedal Size Guide! The can is threaded onto the valve, make sure the valve is in the open position. sin(x)+x "stairs" curve, but which starts from the "flat" part, detect if zone transfer with dig succeed or not via return code, In which tense conclusion line of existing studies should be written. However, some are made of stainless steel, and it is present in less expensive bikes. Once you see the tool these instructions will make better since. The knurled fitting is installed and tightened, all attachments have seals to ensure theres no leakage. Schrader valves a spring inside of them that keeps the valve shut. More importantly, it doesnt cost you anything extra. You need a Schrader core tool to tighten a Schrader valve. If its punctured or worn out, it wont hold air. Slide the tight fitting patch down the Schrader valve stem until it is just above the prepared area. Reposition the Schrader valve squarely within your bike rim if its protruding. Schrader valves are also commonly known as American valves or simply car valves since they're often used in tires for bicycles and motor vehicles. This problem typically happens when grit or dust works its way under the valve's spring mechanism, which causes it not to close correctly. Tried all of the above, and your tube is still leaking air? If the bubble has passed through the valve, then all you need to do is adjust the valve core by tightening it. The Problem : A Leaking Schrader Valve You get a replacement valve stem for $12-$20 on Amazon. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Connect the quick disconnect on the low-pressure side. Perhaps youve never heard of it in relation to cooling your home, but a Schrader valve in an HVAC system keeps refrigerant inside the air conditioner. The main issue is with the valve core, which is the small piece of metal inside the Schrader valve and controls airflow. Subscribe now!https://www.youtube.com/AmplifyDIY?sub_confirmation=1Check out the full channel here: https://www.youtube.com/AmplifyDIYFollow builds in real-time on Instagram! Im having problems with a pressurised hot water system. No sealent needed or recommended!! This video is part of the heating and cooling series of. Turn the shaft counterclockwise to remove the Schrader valve. But if you do the replacement yourself, you only get to spend under $10. Presta Valves 4 Causes of Leakage of Schrader Valves 1. Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. I would go ahead and replace both the valve and the o-ring. Some Schrader valves can be tightened and this might solve the problem. But if its by rust, you should replace the core. "@context": "https://schema.org", How do I determine which valve core remover tool fits my vehicle? Apply a little bit of grease to the plunger and . Remember, the valve core can also clog from rust if the valve stem is rusty. Is that normal? Check out how to determine if the leak is from the valve or not, and how to repair a leaking valve.0:00 Introduction0:20 Symptoms0:57 Find The Leak2:59 Replace Valve Core4:37 Testing The Repair5:00 Conclusion5:50 Don't Forget The Cap!#LeakingTire, #TireLeak, #SchraederValve Need some of the tools or other items I used in this video? This will take the pressure off the tire. Make sure the area around the ports is clean so no contaminated get inside the refrigerant system. Ewwww. Any tips on getting it out? However, if the bubble is around the valve, it means that the valve stem leaks at the base. Bike tyre pump problems - valve and pump. What is the relation between coherence and entanglement? Once the valve stem is bent within the ring-opening and rubs with the tube, there will be leakage. Learn more about Stack Overflow the company, and our products. ", The cap is there to keep dirt & crud out of the Shrader valve. Then just lift the collar on the removal tube and your done. These will vary based on the valve. refrigerant is leaking from your air conditioner, Do Not Sell or Share My Personal Information. "@type": "Question", While Schrader valves are arguable more widespread in their usage than Presta valves, they are not without their problems. This is quite common, particularly if you have been riding without the dust caps on the valve in the first place! The specialty tool has various tips for valve replacement, theyre specific for each style of valve. Loose Valve Core If the valve core is not tight enough, air will escape from the inner tube. Pull the plunger out of the pump tube. Does the ratio of C in the atmosphere show that global warming is not due to fossil fuels? (Quick Answer! 83 Share 6.7K views 7 years ago A/C charging This one is about how to replace the liquid line schrader valve on some Trane units. If you have suggestions or comments they are welcome. I've ruined two tools because the little arms just twist off. ensure all of your bikes components are functioning as they should, Schrader valves core is made primarily of brass, valve stem is bent within the ring-opening, Valve leakage occurs mostly with the valve core, wet the various parts with a soap solution, valve core tool is the best equipment to use when you want to unscrew the valve, also get a replacement valve core if yours has become broken. You're only as good as your customer will allow you to beIf they want junk, sell them junk, but make your junk look neat!!! Win win we like that! But first, lets understand what a Schrader valve does. So, before you can worry about how to fix a leaking Schrader valve, first check the stem for blocking. Get the debris out as best you can, pump up the tire, and see if that has solved the leaking air problem. You won't lose any gas this way. Open the valve. Clicking these and buying something will send a few pennies to help this channel, and does not cost you anything extra:Schrader Valve Tool Kit: https://amzn.to/3nnb09JExtra Valve Cores: https://amzn.to/2Is15kFValve Stem Caps: https://amzn.to/3lwMDpIYou can help me with future projects!https://www.buymeacoffee.com/amplifydiyAmplifyDIY is a channel dedicated to do-it-yourself projects with in-depth tutorials on a wide range of subjects. (Explained! But if the source of air leakage is a tube puncture, then youve to fix it. New videos are always being uploaded every week! 4DIYers 2013All Rights ReservedNo part of this video or any of its contents may be reproduced, copied, modified or adapted, without the prior written consent of the author. The air conditioning coolant leaks. 7 I have a 98 jeep cheerokee sport. Step 3: Adding a Little Oil. #2. Match up the old and new Schrader valves to ensure theyre the same, then insert it into the tip and put the shaft portion of the tool in place, threading on the retainer. The best answers are voted up and rise to the top, Not the answer you're looking for? See you next time at ACSERVICETECH Channel!We've Partnered with TruTechTools.com! Remember, the valve regulates the flow of air into and out of the inner tube. The other note is that the position of the Schrader valve determines if the air will stay or escape. The core has a short outer thread which is screwed into the inner thread of the stem. Tinkering with an AC unit may lead to further damage and more expensive repairs. The two main components of the Schrader valve are the outer cover, also known as a threaded hollow shell, and the poppet valve, which sits inside the hollow shell. It happens whenever the fiber of the tube sealant settles in the center. "text": "The most common cause is that some grit or dust has worked itself under the spring mechanism leading to the valve not closing properly. Push the shaft down in place, gently rotate it and youll feel when it locks into place on the Schrader valve. Use a Schrader valve core tool like the Park Tools VC-1 to tighten up the core and see if that stops the leaks. They are much thinner than Schrader valves and do not have a spring inside. It only takes a minute to sign up. What sets them apart is the valve core, or shell, and a pin or spring that sits inside and keeps the valve closed until you need to manually open it with a tool. The system is evacuated and without pressure but the schrader valve will not turn. If there is some grit in there, it could be the cause of your problems, as it might be preventing the Schrader valve from closing properly. Its two-part build makes a Schrader valve the ideal locking mechanism for machines that occasionally need to be serviced or taken apart, which is definitely the case for HVAC units. If you've checked the Schrader valve, maybe replaced it, can't see there are any punctures, and still the tire loses air just get a new tube. In other situations, the valve itself may be damaged." Flush , blow out with compressed air , vacuum and install freon. Instead, they rely on a locking nut to keep them closed. You can even replace the entire valve if the rust has spread. The valve stem features a spring-packed core that self-seals using the tires pressure. (Quick Answer! This is quite common, particularly if you have been riding without the dust caps on the valve in the first place!