Fountdf Posted June 17 Share Posted June 17 Trying to find a part for the subject A/C Dash Unit. Near the rear wheels on Driver side, is where the Condenser is located. There is/was a valve located at the top right corner of the condenser as shown in the photo. For some reason when I had work done on the A/C that valve was removed. It is needed for the A/C to take an A/C charge, as I understand. Could someone with a similar coach check their A/C unit to see if there is a number on that valve, or if you have a schematic of the unit it may show the part no. Thanks. Link to comment Share on other sites More sharing options...
CLIFF918 Posted June 17 Share Posted June 17 Just looked at my 2002 Diplomat. It has the valve but I can not find any number on it. Don't think it is a fill valve, mine has the fill valve Just to the left of the generator. Had my AC looked at a year or so ago and was told that all the rubber lines should be replaced or it will continue to leak down. does not make sense, time or $$ to try to keep it filled so I opted to run the genny and use the roof AC if needed and get the dash AC fixed when round to it Link to comment Share on other sites More sharing options...
Fountdf Posted June 17 Author Share Posted June 17 Thanks for your efforts. I was concerned that a no. wouldn't be on that valve. The guy who took it off threw it in the trash, so don't have the old one. Take care. Link to comment Share on other sites More sharing options...
Ivan K Posted June 17 Share Posted June 17 52 minutes ago, CLIFF918 said: Just looked at my 2002 Diplomat. It has the valve but I can not find any number on it. Don't think it is a fill valve, mine has the fill valve Just to the left of the generator. Had my AC looked at a year or so ago and was told that all the rubber lines should be replaced or it will continue to leak down. does not make sense, time or $$ to try to keep it filled so I opted to run the genny and use the roof AC if needed and get the dash AC fixed when round to it Could you possibly take a closeup of the 'valve', someone would recognize it. I don't see how it would be something special. Also don't see why all the lines would need to be replaced, someone just did not want to bother isolating a leak point. 1 Link to comment Share on other sites More sharing options...
klcdenver Posted June 17 Share Posted June 17 This from my 2007 diplomat. I do not believe this fitting has a stamped part number. It appears to be an adjustable elbow with a schrader valve. I think any connection as long as not leaking will work. Link to comment Share on other sites More sharing options...
Ivan K Posted June 17 Share Posted June 17 It's a service valve. Under the plastic cap is a stem that can be turned to close the passage. I have personally not seen one on automotive system but they are commonly used on residential HVAC to close the system when replacing other parts and keep refrigerant from leaking out. Why the guy would throw it out is beyond me but it really isn't necessary for our purpose and could be just replaced by an elbow if the hose can't be twisted directly to the condenser port. If necessary, an elbow with a port can be used but there should be an other discharge/charge port sowhere already. 1 Link to comment Share on other sites More sharing options...
Ivylog Posted June 17 Share Posted June 17 Looks like it came with the condenser Monaco sourced and it’s not needed in our applications (mine doesn’t have one) so don't worry about it… hook the line up and go on. Link to comment Share on other sites More sharing options...
CLIFF918 Posted June 17 Share Posted June 17 2 hours ago, Ivan K said: Could you possibly take a closeup of the 'valve', someone would recognize it. I don't see how it would be something special. Also don't see why all the lines would need to be replaced, someone just did not want to bother isolating a leak point. Kcldenver beat me to the picture. 23year old hoses of that type tend to have pinholes that allow the freon to weep out and in extreme cases compressor oil as well. It's a roundabout issue and for now a small amount of diesel for the genny for AC while driving works just fine. Link to comment Share on other sites More sharing options...
Fountdf Posted June 17 Author Share Posted June 17 The problem is that when trying to charge the system...it keeps drawing a vacuum on the low side and will only show pressure of 100 psi on the high side. After talking with a gentleman who parts out various A/C items....he said with out that valve the system will not build pressure. Which appears to be what is happening. So, if that top port in that valve could be tightened to act as a constriction could that possibly act in some way to help build pressure?? who could speak to that issue? Link to comment Share on other sites More sharing options...
CAT Stephen Posted June 17 Share Posted June 17 @Fountdf, The most common cause of AC Dash Air R134a refrigerant leaks are defective schrader valves. With that being said, your next step is to inject r134a compatible UV dye into your AC system to determine the location of the refrigerant leak(s). 1 Link to comment Share on other sites More sharing options...
Ivan K Posted June 17 Share Posted June 17 I'd call it BS what the parts gentleman says. You might have a plugged expansion valve or orifice or desiccant filter and a leak at the high side or just not enough freon, or any combination of that. If there isnt freon supply to the compressor, it can't compress what isnt there. That valve is pretty much just like a water faucet valve. Normally there would be 2 of them to be of any use, if there is an other one, it may is closed. Link to comment Share on other sites More sharing options...
Fountdf Posted June 17 Author Share Posted June 17 We replaced the expansion valve, I took the hoses loose and blew through them, as well as the dryer and the Condenser. All were open. I don't know what is causing the freon to not compress, but I have watched the machine as it evacuated/loaded the freon to the level that is stated for the system. The compressor stayed engaged. So, I know there is a little different twist in these long systems versus regular auto air. I don't know what it is, but The system did work before that valve was removed. And if I am fortunate to find another valve like the one that was removed, I'm going to replace it. At lease I will know if that is the culprit. Keep the comments coming. There is a light at the end of the tunnel. Thanks for your help and ideas. Link to comment Share on other sites More sharing options...
Rikadoo Posted June 18 Share Posted June 18 doing ac like I do you need to look to see where your expansion valve came from, we have been getting aALOT of aftermarket parts from places not of the U.S.A. and its not uncommon to get valves that are either wrong for the application or just plain stuck, many times I just reuse the old one if it had been working before. the other issue is if someone overfilled the system and due to hydraulic lock they bend the reed valves in the compressor causing the compressor to be rendered useless. The valve you are showing in the pic is mearly a close off valve to be used when replacing components ford econoline used them all the time when they sold a stripped chassis cause then the up fitters could add there systems to the trucks, it was a handshake from mfg to builders so they could tap into the system without disturbing the original parts. I recommend finding a competent ac tech that knows what's going on with your system!!! especially if the the last 🤡 just threw away parts, any good tech knows if you change or upgrade ANYTHING you throw them in your "will wait to see box" I have even seen some "techs" leave there gauge set low and high side system valves open which causes the same effect (no low or high side pressures) once they cried loud enough I would go over and "make there day" ac systems are simple once you know the players your working with. but if you are still hellbent on getting one of of those valves look to find someone with a 4 seasons ac catalog, damm tough to do now days cause most parts houses tossed there books to go to the "E catalog" which IS NOT CAPABLE of picture identification. perhaps NAPA auto parts??? 2 Link to comment Share on other sites More sharing options...
trailmug Posted June 18 Share Posted June 18 What fill quantity did they use? Sounds undercharged.. these things by and large take 4 lbs. I agree, ditch the king valve, just another leak point. Schraders aren't the primary seal, the cap is, just like on a car tire. 1 Link to comment Share on other sites More sharing options...
96 EVO Posted June 18 Share Posted June 18 47 minutes ago, trailmug said: Schraders aren't the primary seal, the cap is, just like on a car tire. Huh? The cap on a wheel valve stem is simply to keep foreign objects and dirt out of there! Link to comment Share on other sites More sharing options...
Fountdf Posted June 18 Author Share Posted June 18 Thanks for the insight, Rik W. But, I was dealing with two different repair shops, the tech at big truck shop that threw away the old valves said the same thing you are saying, that valves used by the supplier of the Specific Air Systems A/C- Heater unit, was because it was a pre-charged system. However, that particular shop only did repairs and not recharge. The Tech at the Big Truck Shop did tell me to blow the lines out to be sure the lines were open. and he showed me where to open the lines etc. Had to go to my regular auto repair shop to put a charge in system using their recharge machine. Before deciding to replace the expansion valve the gages on the A/C recharge machine showed the very same signs of vacuum on low side and 100 psi on high side. Before and After replacement of the expansion valve. The new expansion valve was ordered from one of the warehouses that supplies parts to our area of Atlanta. NOW, going back to my original comment about the Valve at the Condenser. I do not have a clue what is causing this problem, but, the Salvage Yard in Kentucky that handles resale of used MH Parts, and the picture you see in the post came from their Web Site. I called them to try and find the part number,etc, for the valve. I was referred to a gentleman that handles the MH A/C Parts at the Salvage Yard. He said the valve you see in the picture is a reversing valve and must be in the system for the unit to Build an A/C charge. And I believe he was referring to the long A/C lines on rear engine Bus Coach Chassis. That is the extent of my knowledge with A/C systems. AND to answer Rob's question about fill quantity, the system says 52 ounces. That is what was programmed into/listed on the Recharge Machine. They tried to add a little more Freon, but the gages didn't show any pressure change. I suppose as Rik mentioned, if the Reed valves were not working properly, the Compressor may not be able to get the pressures up either. Link to comment Share on other sites More sharing options...
trailmug Posted June 18 Share Posted June 18 (edited) Nah, the Schrader seal is hard plastic and is there so you can disconnect and get the cap back on. The O ring in the cap is the primary seal. https://fjcinc.com/service-port-caps-small-but-powerful/ Edited June 19 by trailmug Link to comment Share on other sites More sharing options...
96 EVO Posted June 19 Share Posted June 19 On my daily driver, I have one valve stem plastic cap that has been split for years! That tire doesn't need air anymore often than the other three! I'll remove all my plastic caps, you remove your valve's and screw your caps on, and we will see who does better 🤣! Link to comment Share on other sites More sharing options...
Frank McElroy Posted June 19 Share Posted June 19 4 hours ago, 96 EVO said: On my daily driver, I have one valve stem plastic cap that has been split for years! That tire doesn't need air anymore often than the other three! I'll remove all my plastic caps, you remove your valve's and screw your caps on, and we will see who does better 🤣! Yep that schrader valve is the primary seal. Cap is secondary basic dust cover. No way could that plastic dust cover withstand the high pressures involved. 1 Link to comment Share on other sites More sharing options...
trailmug Posted June 19 Share Posted June 19 High side port has a 1/4" opening, for 0.05 square inches.. 20lbs of force at 400PSI, but I digress. Link to comment Share on other sites More sharing options...
GMan81 Posted June 20 Share Posted June 20 it is a part # 050-00134 SERVICE VALVE. call comfort Air 616-454-2200 Link to comment Share on other sites More sharing options...
Fountdf Posted June 20 Author Share Posted June 20 Thanks for the Valve Number, GMan. Called the number in MI, but at the current time that Part might not be available(they will check availability and call me back). I Did check locally with NAPA, who called their supply warehouse here in Atlanta. The Parts Supplier said that was a Part used by MH Manufacturers, but they didn't stock/have any demand for that Part Number lately and no longer stock it. The Parts Supplier did say that it had a smaller/restriction from similar valves of that type, used in other systems, so the pressure would build and cause the Freon to liquefy before entering the Condenser. So, maybe the Salvage Yard Guy in Kentucky may have known what he was talking about. Again, If I am able to find one we all May, find out something we didn't know or perhaps suspect. Thanks for all of your comments and suggestions, they do help. Take care, David. Link to comment Share on other sites More sharing options...
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