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CrestonM 
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Joined: 08 Sep 2014
Location: Oklahoma
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 Topic: A/C System Question
Posted: 13 Apr 2018 at 4:38pm |
Over the course of the last 15 years or so, the A/C compressor on the L3 has been replaced twice, due to it locking up both times. I think someone here commented once whenever the compressor locks up the condenser should be checked/replaced as well because when the compressor locks up, tiny bits of metal are released, which plug the condenser. Is this true or did I receive bad information?
Also...last summer the A/C blew hot, but after adding 2 cans of freon it blew cool, not cold, for a little while. Does this sound like a leak in the system? If so, what's a good way to find the leak?
I can work on a lot of things, but I've never worked on A/C systems.
Thanks!
Edited by CrestonM - 13 Apr 2018 at 4:39pm
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steve(ill)
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Joined: 11 Sep 2009
Location: illinois
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Posted: 13 Apr 2018 at 5:26pm |
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I don't know the capacity of your system, but if you added 2 cans and " it started working" , that's a good sign.. There is normally a LOW PRESSURE switch that shuts off the compressor so it does not try to run with low gas inside.. Normally there are two port a LOW and HI... you added gas on the LOW side port... The pressures normally run around 35 psi on the LOW and 200 on the HI side... You can buy a pressure gauge, sometimes with the Freon can and measure the psi after you fill... If it is running and only has about 20- 25 psi it will soon stop due to low pressure... If the pump is NOT running, you can put a gauge on the fill port and should measure 90- 100 psi STILL PRESSURE... If you don't have close to 90, then the system is LOW and may not start pumping, or kick in for a few seconds, pump down to 20 and then kick out.... YES, it is a good idea to replace the DRYER ( the black cylinder ) and the orifice tube if you have a FAILED COMPRESSOR, as little pieces can get stuck in them.
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Like them all, but love the "B"s.
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Michael V (NM)
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Joined: 12 Sep 2009
Location: NM
Points: 2474
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Posted: 13 Apr 2018 at 5:51pm |
that L3 is a fairly large system,, will take more than 2 cans,, a leak should show up as an oily place at a connection, or hole in the condense, evaporator, if the leak is kinda small like you have described. a leak on the 'Hi' side will lose Freon a lot faster than on the 'low' side. now,, has this been converted to 134 refrigerant? if compressor is failing often I would suspect mixing of the different oils recommended for the R-12 system vs the oil for the R-134 system..if it has been converted, was the hoses,evap, condenser all flushed? and new oil added?, IIRC the expansion valve would need to be updated also. a set of gages and a vac pump would be really helpful.... FWIW,, when R-12 became basically unavailable(read lotsa $$$) I put a drop in replacement Freon in my L3 that works really good, its called "Glacier Gold", I got it from Jerry KS(use to be AGCO dealer in Johnson KS), he still carries this stuff and will ship...
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Orange Blood
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Location: ColoradoSprings
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Posted: 13 Apr 2018 at 5:51pm |
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The common A/C service tech will tell you to flush flush flush the system, and in most cases replace the condenser when a compressor "fails", the question is what does fail mean??? Well, I like to flush first, and look at what is coming out of the system, before I decide to replace anything. If I know the compressor grenaded, then yes, I know I will be replacing the compressor, the dryer, the condenser, and the orifice/expansion valve. If it just locked up, that is when I wait, to see what the flush tells me. If I see any metal beyond that of a metal flake, or sand grain then I start to consider replacement parts other than the compressor.
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Still in use:
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AC7060IL
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Location: central IL
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Posted: 14 Apr 2018 at 12:42pm |
 Orange Blood wrote:
The common A/C service tech will tell you to flush flush flush the system, and in most cases replace the condenser when a compressor "fails", the question is what does fail mean??? Well, I like to flush first, and look at what is coming out of the system, before I decide to replace anything. If I know the compressor grenaded, then yes, I know I will be replacing the compressor, the dryer, the condenser, and the orifice/expansion valve. If it just locked up, that is when I wait, to see what the flush tells me. If I see any metal beyond that of a metal flake, or sand grain then I start to consider replacement parts other than the compressor.
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Agreed. You may want to try a knowledgeable local auto mechanic who has an AC machine which I THINK does the follow process; -Vacuum system, -Flush system, -Pressurization test, -Refill with 134A. AGAIN I THINK that during this machine's process, you can stop it after perhaps it notes a pressurization drop & replace components, then run it again?? You can also try tightening fittings & run it again. Point is to find source of leak(s). Also don't be afraid to upgrade compressors, hoses, etc to more modern type. Combine's nature is shaking to clean grain. That vibration is detrimental to AC systems, especially aged & older designs.
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CrestonM
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Location: Oklahoma
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Posted: 14 Apr 2018 at 11:23pm |
Thanks guys. I know 134A "refrigerant" (guess they don't call it freon anymore?) has been installed in it before, but I'm in the dark as to whether it was "converted" over the years. I guess it would have to be, for the A/C to blow cold? As of just a few years ago it would keep the cab pretty cool.
I was reading in the operator's manual today, and got the part about looking at the sight glass on the top of the dryer and watching for air bubbles. It said if bubbles are seen to contact the Allis dealer, but that's not an option now. It doesn't say what the cause of the bubbles is, or why they're a cause of alarm. Would somebody explain?
Also, what all needs to be changed out in a conversion to 134A? Lastly, what does the expansion valve do, and why should it and the dryer be replaced when the compressor is?
If you can't tell by now, I know little to nothing about A/C systems, but I'd really like to learn whatever I can.
Edited by CrestonM - 14 Apr 2018 at 11:27pm
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shameless dude
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Posted: 15 Apr 2018 at 8:54am |
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put a swamp cooler on it
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SteveM C/IL
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Joined: 12 Sep 2009
Location: Shelbyville IL
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Posted: 15 Apr 2018 at 9:06am |
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Bubbles in the glass means low on gas. Add till they are gone. I don't know if my F2 has a low press switch. Never had to jump it to add gas. Lube oil is carried by gas through system.Running low freon can promote compressor lock.
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bradley6874
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Posted: 15 Apr 2018 at 11:31am |
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Look for two round fittings if it was correctly converted to 134 they will be just like a car if there there buy a set of gauges from Auto parts store right where the gauges are at there with be a ultra viloet kit to find a leak put the die in if you had to add two cans THERE is a leak the gauge kit will have a charge chart for pressure and temp to correct the the charge then you need to decide if you want to fix or charge ever year but remember the refigerant also cools the compressor so as your running it low on charge your cooking the compressor it will eventually fail again ! correct charge equals a happy system happy system equals happy operator 😁😁😁
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You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul
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Orange Blood
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Joined: 29 Nov 2010
Location: ColoradoSprings
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Posted: 15 Apr 2018 at 12:54pm |
CrestonM wrote:
Thanks guys. I know 134A "refrigerant" (guess they don't call it freon anymore?) has been installed in it before, but I'm in the dark as to whether it was "converted" over the years. I guess it would have to be, for the A/C to blow cold? As of just a few years ago it would keep the cab pretty cool.
I was reading in the operator's manual today, and got the part about looking at the sight glass on the top of the dryer and watching for air bubbles. It said if bubbles are seen to contact the Allis dealer, but that's not an option now. It doesn't say what the cause of the bubbles is, or why they're a cause of alarm. Would somebody explain?
Also, what all needs to be changed out in a conversion to 134A? Lastly, what does the expansion valve do, and why should it and the dryer be replaced when the compressor is?
If you can't tell by now, I know little to nothing about A/C systems, but I'd really like to learn whatever I can.
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As far as the conversion, I have seen it done a couple of ways, some just replace the gas (freon/refrigerant) and slap a sticker on it, others replace the compressor, and the fill valves, I am sure there are yet more ways.
The expansion valve is the business end of the cooling system. so the way an A/C system works, is on the principal of an expanding gas gets colder, in this case the refrigerant is pressurized by the compressor, and sent up to the evaporator near the cab, the gas is held under pressure by the expansion valve, or in some systems and orifice. On the other side of the expansion valve, the gas is released to what becomes the suction side, thus the gas expands greatly under the now relatively "low" pressure, and when that happens it gets really cold, just about the time it goes into the evaporator coil, now blow some air through it, and presto chango you have A/C. There is much more to it than that, but that is part of the basics of A/C.
The dryer should always be replaced when a compressor and for sure when it grenades, because, the dryer contains descant, I.E pulls water out of the freon, water and freon mixing creates acid, very bad for compressors, and other components. The descant, only lasts for so long, and can only hold so much moisture, I.E. the need for replacing when servicing the compressor. The dryer is also a very voluminous chamber, and will trap all kinds of metal particles, than cannot be flushed out, nor should you ever flush your dryer to begin with.
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Still in use:
HD7 WC C CA WD 2-WD45 WD45LP WD45D D14 3-D17 D17LP 2-D19D D19LP 190XTD 190XTLP 720 D21 220 7020 7030 7040 7045 3-7060
Projects: 3-U UC 2-G 2-B 2-C CA 7-WC RC WDLP WF D14 D21 210 7045 N7
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SteveM C/IL
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Joined: 12 Sep 2009
Location: Shelbyville IL
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Posted: 15 Apr 2018 at 12:59pm |
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my compressor is 2cyl York design. Has screws on fittings at compressor which are backed out to close fitting connections. The can be screwed full in to isolate hoses frm compressor. They need centered to charge system and backed out before disconnecting charge hoses.They dont use a schrader valve.
Edited by SteveM C/IL - 15 Apr 2018 at 1:01pm
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