Daskuppler Posted March 5, 2022 Share Posted March 5, 2022 Hello Everyone, I have a 2002 Impreza with about 135k on it. Last summer the AC started to not blow as cold as desired, in fact it was borderline warm. I added some refrigerant assuming I would have to address a leak later but I could limp through the summer. Adding refrigerant helped , but temperatures soon dropped at the vents, even though the gauge still read around 32 psi. Best I can tell is the compressor kicks on as there is a load on the motor when I turn the AC on. The low pressure line is slightly cooler than the engine bay temperatures but by no means cold. High pressure line is hot. The condenser at the front has seen better days and has a lot of damaged fins, though no sign of a leak. I checked pressure again without the car running and it read at almost 50psi. I'm not quite sure what happened but that's where it sits. There is some sign of leakage on the high pressure line where it goes from a rubber hose to the hard piping attached to the compressor, but this was not present last summer. I am guessing this is due to the fact that the system is now overcharged. Any ideas where to go from here? Cheers Link to comment Share on other sites More sharing options...
lmdew Posted March 5, 2022 Share Posted March 5, 2022 Get it evacuated. Change the compressor and Evap o-rings and then service the system. A good AC Shop will pull a vacuume and then properly service it. Worth the money. I have pulled a slight vaccume with my hand pump and then serviced the system based on the specified amount of coolant. It works. 2 Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 5, 2022 Share Posted March 5, 2022 1 Link to comment Share on other sites More sharing options...
Daskuppler Posted March 5, 2022 Author Share Posted March 5, 2022 Is it really leaking? It's been holding for almost a year. Obviously there is a leak at one location, but could that be because it is overcharged? Link to comment Share on other sites More sharing options...
idosubaru Posted March 6, 2022 Share Posted March 6, 2022 On 3/4/2022 at 7:18 PM, Daskuppler said: Hello Everyone, I have a 2002 Impreza with about 135k on it. Last summer the AC started to not blow as cold as desired, in fact it was borderline warm. I added some refrigerant assuming I would have to address a leak later but I could limp through the summer. Adding refrigerant helped , but temperatures soon dropped at the vents, even though the gauge still read around 32 psi. Best I can tell is the compressor kicks on as there is a load on the motor when I turn the AC on. The low pressure line is slightly cooler than the engine bay temperatures but by no means cold. High pressure line is hot. The condenser at the front has seen better days and has a lot of damaged fins, though no sign of a leak. I checked pressure again without the car running and it read at almost 50psi. I'm not quite sure what happened but that's where it sits. There is some sign of leakage on the high pressure line where it goes from a rubber hose to the hard piping attached to the compressor, but this was not present last summer. I am guessing this is due to the fact that the system is now overcharged. 1. Push valve to let some refrigerant out. Done. 2. If you think it’s leaking, or don’t trust the amount in the system - I’d replace the orings at the compressor lines and put 20 ounces of refrigerant (put however much the sticker says that’s usually on the upper radiator support) in it and call it a day. The orings get brittle and hard like plastic instead of soft and pliable like an oring. Interestingly all the other orings can be fine in the entire system except those two. I assume it’s due to heat cycling at the compressor/engine increasing the degradation rate of the rubber. The cause doesn’t matter, what’s important is how common this is on older Subarus. Done it to countless Subarus, and importantly, only once to each one! Those lines at the compressor leak *all the time*. 2 Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 6, 2022 Share Posted March 6, 2022 most every time I've followed a thread where a system was overcharged, there has been a 'hooting' noise reported. Sometimes when the car/system is turned off. 1 Link to comment Share on other sites More sharing options...
Daskuppler Posted March 7, 2022 Author Share Posted March 7, 2022 I looked at this morning. When I first turned the AC on, the compressor was short cycling. It would run for about 2 seconds then turn off and repeat. Since the gauge showed that the system was overcharged, I let a little bit out. It then stopped short cycling and never came back one. I put the gauge back on, and the pressure read 0. I added about 4 ounces and the compressor kicked on, the low pressure line was cold, but it was still short cycling a little bit. It would run for about 15 seconds then shut off and come back on about 20 seconds later. While it is cycling, pressure rises to about 38 while the compressor is off and drops to 10 while it is running. There is an oily residue where the high pressure line turns to rubber coming off of the compressor. Bad compressor? Bad pressure switch? Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 7, 2022 Share Posted March 7, 2022 I have had to replace the high pressure hose once on my WRX, twice on our old Outback. The Outback also got a new low-side hose. They don't last forever. Link to comment Share on other sites More sharing options...
heartless Posted March 8, 2022 Share Posted March 8, 2022 19 hours ago, Daskuppler said: There is an oily residue where the high pressure line turns to rubber coming off of the compressor. how about bad hose... there should not be oily residue at that junction. 1 Link to comment Share on other sites More sharing options...
Daskuppler Posted March 8, 2022 Author Share Posted March 8, 2022 29 minutes ago, heartless said: how about bad hose... there should not be oily residue at that junction. I'm working on getting one. Looks like they are $340 from Subaru. Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 8, 2022 Share Posted March 8, 2022 check rock auto - or, if you are near a larger city, radiator shops often can fix/make a hose for you. Link to comment Share on other sites More sharing options...
lmdew Posted March 8, 2022 Share Posted March 8, 2022 www.car-part.com 1 Link to comment Share on other sites More sharing options...
Daskuppler Posted March 8, 2022 Author Share Posted March 8, 2022 2 hours ago, 1 Lucky Texan said: check rock auto - or, if you are near a larger city, radiator shops often can fix/make a hose for you. I just ordered a new high pressure and low pressure line. I also got a new condenser since mine is pretty chewed up after a rough 135k miles. I also got an O-ring set since the system will be apart. I'll post back once it is all installed and it warms up a little. 2 Link to comment Share on other sites More sharing options...
Daskuppler Posted March 10, 2022 Author Share Posted March 10, 2022 On 3/8/2022 at 12:35 PM, Daskuppler said: I just ordered a new high pressure and low pressure line. I also got a new condenser since mine is pretty chewed up after a rough 135k miles. I also got an O-ring set since the system will be apart. I'll post back once it is all installed and it warms up a little. Back to square 1, Rock Auto will not Ship to Colorado. Link to comment Share on other sites More sharing options...
lmdew Posted March 11, 2022 Share Posted March 11, 2022 Lots of selfserve lots in CO. Littleton is good as are the UPAP. www.car-part.com is also good. Link to comment Share on other sites More sharing options...
laegion Posted March 12, 2022 Share Posted March 12, 2022 What kind of machine are you using to charge your system? Link to comment Share on other sites More sharing options...
Daskuppler Posted March 12, 2022 Author Share Posted March 12, 2022 On 3/10/2022 at 6:13 PM, lmdew said: Lots of selfserve lots in CO. Littleton is good as are the UPAP. www.car-part.com is also good. Can you really trust a partially rubber line that's been in a junkyard for who knows how long? 15 hours ago, laegion said: What kind of machine are you using to charge your system? Just the store bought cans. A/C Pro Synthetic Refrigerant w/ oil to be exact. If the system isn't cooling as desired, I can always take it to a shop and have them vac it down. It's still cheaper than paying them for refrigerant. Link to comment Share on other sites More sharing options...
laegion Posted March 13, 2022 Share Posted March 13, 2022 8 hours ago, Daskuppler said: Can you really trust a partially rubber line that's been in a junkyard for who knows how long? Just the store bought cans. A/C Pro Synthetic Refrigerant w/ oil to be exact. If the system isn't cooling as desired, I can always take it to a shop and have them vac it down. It's still cheaper than paying them for refrigerant. You mentioned adding 4oz, are you weighing the can before and after adding? I've only ever done A/C service myself with a machine during a very brief stint as a mechanic. It seems to me that manufacturers rate their systems by volume and not pressure...and the only way to be sure of volume is to evacuate the system and create as much vacuum as possible before filling. I'm no expert however, as they basically only showed me how to operate the machine, not what was actually going on and since then I've just had a shop deal with the A/C stuff. I had the A/C in my '95 serviced last year and they added about a pound of refrigerant and it only cost me $130 total. I dunno what it costs where you're at; but that cost was worth it to me rather than waste time messing with non-professional kits. Link to comment Share on other sites More sharing options...
Daskuppler Posted March 14, 2022 Author Share Posted March 14, 2022 On 3/12/2022 at 10:44 PM, laegion said: You mentioned adding 4oz, are you weighing the can before and after adding? I've only ever done A/C service myself with a machine during a very brief stint as a mechanic. It seems to me that manufacturers rate their systems by volume and not pressure...and the only way to be sure of volume is to evacuate the system and create as much vacuum as possible before filling. I'm no expert however, as they basically only showed me how to operate the machine, not what was actually going on and since then I've just had a shop deal with the A/C stuff. I had the A/C in my '95 serviced last year and they added about a pound of refrigerant and it only cost me $130 total. I dunno what it costs where you're at; but that cost was worth it to me rather than waste time messing with non-professional kits. I agree, having a shop do it is a better option. I can recharge a nearly empty system in my garage with an auto parts store kit for $50. If thje AC doesn't perform as desired, I can always take it to a shop where they recover the refrigerant I already put in, vacuum the system, and put it back in. I get charged almost nothing since the refrigerant was already there. I guessed at 4 ounces based on what was left in the can. No, none of it is done per spec, but it works for the most part. When I did the same process on my wife's '14 forester, it seems to work fine. The air at the vents meets factory specifications so I'm happy with the fix. The shop wouldn't install a Subaru Compressor but still wanted the $1100 to do the job. Link to comment Share on other sites More sharing options...
Daskuppler Posted March 24, 2022 Author Share Posted March 24, 2022 I replaced the evaporator, drier, high pressure line, and the valve core on the low pressure line. I then pulled a vacuum on the system for about 1.5 hours. I turned the pump off and it held vacuum for 45 minutes at which point I hooked up the refrigerant. The system took roughly 16 ounces (guessing by what it felt like was left in the can) and the AC was blowing cold. It was cold at the time (35 degrees) so I didn't test it too much. Today, it was about 65 so I gave the AC a run and it was cold, though not ice cold, for a while then it would get warm, then cold, then warm, and so on. I got home, threw the gauges on it and low side reads 52psi with the compressor off and high side reads 80psi. Witch compressor running, low side drops to about 30 and high side goes to about 90. I pulled some refrigerant out and low side pressure drops to about 20psi when running, but is still about 50 when off. What's going on? I'm lost. Link to comment Share on other sites More sharing options...
idosubaru Posted March 24, 2022 Share Posted March 24, 2022 Is the clutch slipping? There’s not much more to the system. Pressure switches, clutch, and compressor? 1. verify properly charged. 2. Pressure switches - FSM should show how to test them. 3. clutch - is it switching on and off or making noises or slipping? 4. Compressor is weak FSM probably has some notes on pressures. Link to comment Share on other sites More sharing options...
Daskuppler Posted March 24, 2022 Author Share Posted March 24, 2022 17 minutes ago, idosubaru said: Is the clutch slipping? There’s not much more to the system. Pressure switches, clutch, and compressor? 1. verify properly charged. 2. Pressure switches - FSM should show how to test them. 3. clutch - is it switching on and off or making noises or slipping? 4. Compressor is weak FSM probably has some notes on pressures. It does not sound like the compressor is slipping, but I don't know. I can throw some feeler gauges in and check the gap. It runs for a minute or so then shuts off and comes back on 30 seconds or so later. It was blowing cold air when running initially but slowly got worse and now only blows hot air even with the compressor running. Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 26, 2022 Share Posted March 26, 2022 often, there will be a lot of reddish dust flung around near the comp. if the clutch has been slipping. Link to comment Share on other sites More sharing options...
Daskuppler Posted March 26, 2022 Author Share Posted March 26, 2022 10 minutes ago, 1 Lucky Texan said: often, there will be a lot of reddish dust flung around near the comp. if the clutch has been slipping. Definitely none of that. There was a little bit of leakage in my the low pressure line, but I replaced the o ring and it's hosting vacuum now. Link to comment Share on other sites More sharing options...
Daskuppler Posted May 11, 2022 Author Share Posted May 11, 2022 So I checked the clutch air gap and it was at about .23, which is way out of spec. I pulled the clutch and removed one shim from the shaft and put it all back together. It seems to be working better, but I noticed the side vents blow cold air and the middle vents blow coolish air. When the compressor cycles off the center vents turn hot (like the heater is on) and the side vents turn coolish before the compressor comes back on. Any thoughts? Link to comment Share on other sites More sharing options...
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