RHeller1 Posted June 9, 2017 Report Share Posted June 9, 2017 I am an idiot when it comes to A/C systems. My coil is freezing up on my Volvo. Starts up the day SUPER cold and then fades as day goes on. Took it apart at end of day and found this. Anyone know what could be causing this? btw, the cabin filter was just replaced. Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 9, 2017 Report Share Posted June 9, 2017 Expansion valve could be sticking. What temp setting are you running at on the a/c panel? If it is full cold, you might try starting it out at a warmer setting. Keeping a high fan setting can help also. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RHeller1 Posted June 9, 2017 Author Report Share Posted June 9, 2017 well, I was doing the complete opposite...lol...max cold on low fan speed...I will change it up and see if it helps! THANK YOU! Link to comment Share on other sites More sharing options...
Darryl&Rita Posted June 9, 2017 Report Share Posted June 9, 2017 Does the Volvo system have any freeze sensor? Should be some type of sensor to turn off the compressor occasionally, and let the coils clear off. I have been wrong before, I'll probably be wrong again. 2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication 2006 smart fourtwo cdi cabriolet 2007 32.5' Fleetwood QuantumPlease e-mail us here. Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 9, 2017 Report Share Posted June 9, 2017 26 minutes ago, RHeller1 said: well, I was doing the complete opposite...lol...max cold on low fan speed...I will change it up and see if it helps! THANK YOU! Not a problem, the freezing comes about from a high flow of refrigerant through the evaporator, combined with a build up of condensation, which equates to ice build up. The higher fan speed keeps the evaporator temp elevated and reduces the condensation. The expansion valve controls the flow of refrigerant to the evaporator and it is controlled by the a/c controller. There could be an issue in the controller not getting a good temperature reading from the evaporator, not sending a proper signal to regulate flow to the expansion valve or a bad expansion valve. The modulation of the temp, combined with high airflow is basically a manual reversion of the system. If the expansion valve were stuck in a high flow setting, you won't see any relief to the manual method I described. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 9, 2017 Report Share Posted June 9, 2017 If you have a Gen 2 Volvo, you should check the Diagnostics page of the DID for fault codes. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RHeller1 Posted June 9, 2017 Author Report Share Posted June 9, 2017 I have no fault codes. I will try manipulating the temp and fan speed to see if that takes care of it. I might try replacing the temp sensor on the blower. Link to comment Share on other sites More sharing options...
I'mdonewiththis forum Posted June 9, 2017 Report Share Posted June 9, 2017 One thing to keep in mind is if the ice is white and frosty then you most likely have an air flow issue and if it is a hard clear ice then look for a drain problem. Those are the two most common problems that I have found. Link to comment Share on other sites More sharing options...
RandyA Posted June 10, 2017 Report Share Posted June 10, 2017 I'm guessing you have a R134 system. If you have a leak, like around a line connection with an O ring, you will slowly lose Freon. Contrary to what a lot of folks think, a loss of Freon will cause a drop in temperature across your evaporator. Since pressure is directly related to temperature, the pressure on your low side will be higher on a hot day. That and warmer air blowing across the evaporator may be enough to keep the evaporator from freezing. When the ambient temperature drops, so will your system pressure. Lower pressure results in a lower temperature and the evaporator will ice up. If it is 70 degrees F outside and the pressure on your low side is below 30 psi icing is common. At 90 degrees F that same system charge will rise to about 45 psi which is high enough to prevent freezing. You do have pressure switches for both too low and too high that will disengage the compressor clutch and some systems have temperature sensors on the evaporator that will cut out the compressor if the evaporator freezes. But, despite the pressure/temperature they are designed for it is not uncommon for one or more to be out of tolerance. Bottom line - you need to put a gauge set on your system to see what both the low and high side pressures are and compare them to a temperature/pressure chart. . You will most likely find that you are low on Freon (R134A) and will need to add enough to bring low side pressure up to spec. If it doesn't hold, you will have to start looking for the leak. Randy, Nancy and Oscar "The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks. ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired! Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 10, 2017 Report Share Posted June 10, 2017 Another thing to check, is your cabin air filter. When you have the fan on high, do you have a high air flow out of your vents? And by that, I am referring to before The evaporator freezes up. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RHeller1 Posted June 10, 2017 Author Report Share Posted June 10, 2017 the cabin air filter is brand new, 2 weeks old. and yes, there is high flow out the vents...well until freeze up. Gonna get some gauges so I can see whats going on. anyone know what the high and low pressures should be at? Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 10, 2017 Report Share Posted June 10, 2017 This is an older manual, but pretty well covers what you are looking for. Volvo AC Service Manual John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RHeller1 Posted June 10, 2017 Author Report Share Posted June 10, 2017 thanks! Link to comment Share on other sites More sharing options...
RandyA Posted June 11, 2017 Report Share Posted June 11, 2017 8 hours ago, RHeller1 said: the cabin air filter is brand new, 2 weeks old. and yes, there is high flow out the vents...well until freeze up. Gonna get some gauges so I can see whats going on. anyone know what the high and low pressures should be at? Use the temperature/pressure chart I linked you to in my post above. Click here. Harbor Freight currently has a decent gauge set for under $50. But, you will also need a charge hose that taps a R134A can. This budget version means you will need to attach the gauge (blue) to the low pressure side, get reading and if low remove the gauge and use the yellow charge/can tap hose to add vapor (do not invert can and charge liquid). An initial 25 psi reading would require a full can to bring it up to 35 psi. When I use the cans I warm them in a pail of hot tap water for 5-10 minutes, dry the top off, screw on the tap, let a little gas out to purge air from the charge hose and plug it onto the LOW pressure fitting. High side valve (red) should be turned off - do not try to add gas to the high side. Again - this is the "budget" method since the HF gauge set is designed for charging from a 30 lb canister. Be sure the high side is in the range on the chart. If it is over STOP and take your truck to someone that is knowledgeable and certified for automotive AC. For safety wear goggles and gloves when working with R134A - a blow-out can freeze skin and mess up your eyes. Actually, if you are unsure about what to do it is best to take the truck to a pro. Lowest price for R134A will most likely be Wal-Mart. 12 oz can is $4.88 at our store. Auto parts stores sell same size for about $11. Synthetic, which you do not need or want, is about $21. Wal-Mart will also have the charge hose that taps a can and goes to the low side fitting. Some of the fancier charge hoses even have a low pressure gauge built in. The low and high side ports are different sizes so you cannot connect a gauge set backwards. On my VNL the low side port is on the firewall over the top of the engine valve cover. The high side port is on the left near the radiator above the steering box. Read the manual linked in VegasFlyer's post above to familiarize yourself with the system and adding Freon. Randy, Nancy and Oscar "The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks. ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired! Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 11, 2017 Report Share Posted June 11, 2017 1 hour ago, RandyA said: Use the temperature/pressure chart I linked you to in my post above. Click here. Harbor Freight currently has a decent gauge set for under $50. But, you will also need a charge hose that taps a R134A can. This budget version means you will need to attach the gauge (blue) to the low pressure side, get reading and if low remove the gauge and use the yellow charge/can tap hose to add vapor (do not invert can and charge liquid). An initial 25 psi reading would require a full can to bring it up to 35 psi. When I use the cans I warm them in a pail of hot tap water for 5-10 minutes, dry the top off, screw on the tap, let a little gas out to purge air from the charge hose and plug it onto the LOW pressure fitting. High side valve (red) should be turned off - do not try to add gas to the high side. Again - this is the "budget" method since the HF gauge set is designed for charging from a 30 lb canister. Be sure the high side is in the range on the chart. If it is over STOP and take your truck to someone that is knowledgeable and certified for automotive AC. For safety wear goggles and gloves when working with R134A - a blow-out can freeze skin and mess up your eyes. Actually, if you are unsure about what to do it is best to take the truck to a pro. Lowest price for R134A will most likely be Wal-Mart. 12 oz can is $4.88 at our store. Auto parts stores sell same size for about $11. Synthetic, which you do not need or want, is about $21. Wal-Mart will also have the charge hose that taps a can and goes to the low side fitting. Some of the fancier charge hoses even have a low pressure gauge built in. The low and high side ports are different sizes so you cannot connect a gauge set backwards. On my VNL the low side port is on the firewall over the top of the engine valve cover. The high side port is on the left near the radiator above the steering box. Read the manual linked in VegasFlyer's post above to familiarize yourself with the system and adding Freon. That was all great info, I will add that I just bought this set on eBay that is superior the HF setup. Gauge Set John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RandyA Posted June 12, 2017 Report Share Posted June 12, 2017 VegasFlyer - yes, it is a nice set and includes some features the HF unit does not have. One comment though: Back when all this licensing and certification stuff became mandatory to buy R12 and R22 I took the classes to get both Universal and Type A (automotive) certification. One of the instructional topics was NOT to use the same set of hoses and manifold block via adapters to service systems with different types of Freon and oil. I personally can't say that using the same set on R22 and then R134A is going to cause system contamination of either system but I do adhere to the concept. I have three different manifold gauge sets with their own hoses that I use with the refrigerants and systems I occasionally service. BTW - these are all my systems, I do not do any service work outside of my family, but every year it is, "Dad, our heat pump is not working, can you come check it?" -or- "Dad, the AC in my car/truck is not very cold, can I bring it over so you can check it?" Truthfully, AC service is not as easy as the aftermarket folks want you to believe. If not done properly you can be seriously hurt. Finding and repairing a leak, which on a car/truck is usually an O ring seal, blown high pressure hose or seals in the compressor. I have the electronic leak detector, vacuum pump, boxes of O rings and filling tools, flush tools, silver/bronze gas welding rods for copper lines, braze-on access valves, cap buster and recovery bags for older R12 and R22 systems. Other than adding a few ounces of R134A to an automotive system that has one of those six month leaks it really is best not to be getting into more involved AC service work without the proper training and tools. Randy, Nancy and Oscar "The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks. ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired! Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 12, 2017 Report Share Posted June 12, 2017 1 hour ago, RandyA said: VegasFlyer - yes, it is a nice set and includes some features the HF unit does not have. One comment though: Back when all this licensing and certification stuff became mandatory to buy R12 and R22 I took the classes to get both Universal and Type A (automotive) certification. One of the instructional topics was NOT to use the same set of hoses and manifold block via adapters to service systems with different types of Freon and oil. I personally can't say that using the same set on R22 and then R134A is going to cause system contamination of either system but I do adhere to the concept. I have three different manifold gauge sets with their own hoses that I use with the refrigerants and systems I occasionally service. BTW - these are all my systems, I do not do any service work outside of my family, but every year it is, "Dad, our heat pump is not working, can you come check it?" -or- "Dad, the AC in my car/truck is not very cold, can I bring it over so you can check it?" Truthfully, AC service is not as easy as the aftermarket folks want you to believe. If not done properly you can be seriously hurt. Finding and repairing a leak, which on a car/truck is usually an O ring seal, blown high pressure hose or seals in the compressor. I have the electronic leak detector, vacuum pump, boxes of O rings and filling tools, flush tools, silver/bronze gas welding rods for copper lines, braze-on access valves, cap buster and recovery bags for older R12 and R22 systems. Other than adding a few ounces of R134A to an automotive system that has one of those six month leaks it really is best not to be getting into more involved AC service work without the proper training and tools. Great points Randy! John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RandyA Posted June 12, 2017 Report Share Posted June 12, 2017 Some how or other a paragraph of my above posting was deleted and I did not realize it until just now. Anyway, this is the "lost" paragraph: But it is always nice to have a complete set of gauges (high and low side) that you can attach to the R134A system on your truck when things are not working right. Just using the gauges without doing any service work can tell you if there is a leak, bad expansion valve, dirty air filter, dirty unit coils, contamination in the receiver-dryer, no Freon (flat system), bad pressure switches, broken control wires, faulty compressor, and much more. This type of system diagnosis does require a high pressure side connection/gauge as well as low side. There are multiple good books and on-line resources on how to read your gauges over a given time period as the system is operating, or trying to operate, to pinpoint a problem. The second benefit to this is having enough knowledge to keep an unethical service tech from selling you a repair job that you don't need. Randy, Nancy and Oscar "The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks. ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired! Link to comment Share on other sites More sharing options...
RHeller1 Posted June 16, 2017 Author Report Share Posted June 16, 2017 So here is where I am at. I got some gauges and my low side cycles from 24psi to 30psi, while my high side cycles from 130psi to 227psi. This is at temps of 82 degrees outside. Is this correct in interpreting I am low on the low side and a bit high on the high side? I am guessing the dryer is original and quite possibly a culprit for a problem. Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 16, 2017 Report Share Posted June 16, 2017 I would say you are low on refrigerant. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 16, 2017 Report Share Posted June 16, 2017 The variations in pressures, as far as the high pressure being borderline high, COULD be an indication of a problem with the expansion valve, however, I would add more refrigerant first and get that squared away and reassess the pressures. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
RHeller1 Posted June 17, 2017 Author Report Share Posted June 17, 2017 added more r134a to the system, my low side now cycles 40 to 45psi, but my high cycles from 170 to 250. this is at 83 degrees. Link to comment Share on other sites More sharing options...
VegasFlyer Posted June 17, 2017 Report Share Posted June 17, 2017 What sort of temp are you getting out of the a/c vents? John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
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