AC trouble
08-05-2011, 07:36 PM
#1
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Join Date: Jul 2007
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AC trouble
I know most people dont care about AC because of gas milage and how much horsepower it robs, but living in the area I do near Atlanta, some days get up to 102 degrees and its just insane to drive around in a mustang with dark red leather and black plastic pieces on the dash.
I have a 1987 mustang with the 2.3L engine. The A/C system is from a 91 - to 93 set up (that includes crank pully's and compressor braket). The only original parts would be the evaporator and condenser that works from 87 to 93. As of this month everything is new, or newish. Everything was bought last summer except the condenser, which I bought this summer after finding a leak in it. The evap was replaced about 5 years ago. I have of course replaced all the seals, and the new liquid line includes the new orfice tube.
Now for the issue I keep getting. I run a vacuum on the system for at least an hour. Then I put in about 2 lbs of R134a into the system, along with 8 oz of pag 46 oil. The low side well be about 35 psi, and the high side around 250. The car well be really really cold. Then When I drive the car a few times, the air starts to not be very cool at all, enough to keep me from dieing of heat, but i'm still able to sweet. I get home and check it the pressure in the system, and its jumped to 45 to 65 on the low side, and about 250 on the high side. I'm trying to figure out how all of a sudden the low side keeps getting higher.
As a couple of side notes, I'v drained the system, vacuumed it, and recharged it two more times. Each time starts out at 35 psi, blowing cold and working for a few days, and then eventually getting higher on the low side, never seen it any higher than 65 psi though.
I have dye in the system, and can't find any leaks that way. I also have the snap leak sniffer, and find nothing that way, the system seems to be sealed tight. So if its air getting in the system and causeing ice build up inside of the evap to make it get higher, i'm not sure how, unless the evap is leaking, cause i'm unable to check that for dye or use my sniffer cause of its location.
A second and last side note, Each time that i'v drained the system it seems to indicate a clog. I would start applying my vacuum to the system once it reaches 0 psi. it would get to 10 inches of vacuum, and then all of a sudden i hear a sound, like a knock or thud coming from the evaporator. All of a sudden the system goes back to 5 psi, and continues to let more freon back out. That's were I start to assume an ice build up, but i'm not sure, and it seems like a big job to pull my dash out again to replace a part, only to still have the problem again. I am hoping someone has had a similar problem, and have a good explanation of how to fix this.
I have a 1987 mustang with the 2.3L engine. The A/C system is from a 91 - to 93 set up (that includes crank pully's and compressor braket). The only original parts would be the evaporator and condenser that works from 87 to 93. As of this month everything is new, or newish. Everything was bought last summer except the condenser, which I bought this summer after finding a leak in it. The evap was replaced about 5 years ago. I have of course replaced all the seals, and the new liquid line includes the new orfice tube.
Now for the issue I keep getting. I run a vacuum on the system for at least an hour. Then I put in about 2 lbs of R134a into the system, along with 8 oz of pag 46 oil. The low side well be about 35 psi, and the high side around 250. The car well be really really cold. Then When I drive the car a few times, the air starts to not be very cool at all, enough to keep me from dieing of heat, but i'm still able to sweet. I get home and check it the pressure in the system, and its jumped to 45 to 65 on the low side, and about 250 on the high side. I'm trying to figure out how all of a sudden the low side keeps getting higher.
As a couple of side notes, I'v drained the system, vacuumed it, and recharged it two more times. Each time starts out at 35 psi, blowing cold and working for a few days, and then eventually getting higher on the low side, never seen it any higher than 65 psi though.
I have dye in the system, and can't find any leaks that way. I also have the snap leak sniffer, and find nothing that way, the system seems to be sealed tight. So if its air getting in the system and causeing ice build up inside of the evap to make it get higher, i'm not sure how, unless the evap is leaking, cause i'm unable to check that for dye or use my sniffer cause of its location.
A second and last side note, Each time that i'v drained the system it seems to indicate a clog. I would start applying my vacuum to the system once it reaches 0 psi. it would get to 10 inches of vacuum, and then all of a sudden i hear a sound, like a knock or thud coming from the evaporator. All of a sudden the system goes back to 5 psi, and continues to let more freon back out. That's were I start to assume an ice build up, but i'm not sure, and it seems like a big job to pull my dash out again to replace a part, only to still have the problem again. I am hoping someone has had a similar problem, and have a good explanation of how to fix this.
08-06-2011, 12:53 AM
#3
You may also be over charging the system. I don't know the spec, but it should be about 80% of the R22 charge, adjusted for ambient temp. The gauges should be marked to help figure that. The other is how the oil is distributed in the system. Did you put it all in one place, or did you put a few oz in each line, the drier, evaporator, condenser, etc?
08-06-2011, 07:39 PM
#5
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The orifice tube is brand new, and i put about 5 oz in the compressor, and spread the rest around in other area's. I did alittle more with it today. I used a second industry type of vacuum pump, that my dad borrowed from his work for me. I always thought maybe it was just me or my gauge is broken or something, but now i think i do have a leak somewhere, cause the gauge only shows that i'm pulling 25 of vacuum. Also when It did that thing were after i let all the froen out, and i start to pull a vacuum, you hear a thud kind of noise comeing from the evaporator, and this time it went back up to 25 psi, and i had to let that out before i could continue to vacuum. Tried again, and made a second thud noise, in the same area, and went up to 10 psi. Again let that freon out and continued. Got it up to 25 inches of vacuum. I then disconnected the system from the gauge. waited 15 minutes, then reconnected it. It had dropped to 15 inches of vacuum.
The problem is, everything is new, all the seals are new. The only thing with alittle bit of age would be the evaporator (with 5 years + or - a year). The only other thing i'm considering is the r134a adapters might have a leak. Tomorrow i am gonna go through and replace all the seals again, and put on new adapters. If i still leak after that my only option I can see is to replace the evap again. Unless anyone else has any other idea's.
The problem is, everything is new, all the seals are new. The only thing with alittle bit of age would be the evaporator (with 5 years + or - a year). The only other thing i'm considering is the r134a adapters might have a leak. Tomorrow i am gonna go through and replace all the seals again, and put on new adapters. If i still leak after that my only option I can see is to replace the evap again. Unless anyone else has any other idea's.
08-07-2011, 01:02 PM
#8
Join Date: Aug 2011
Location: new hampshire
Posts: 5
mustang ac
when i used to work for for ford in the 70s / 80s this system ran on r 12 feron gas your highside or dis charge side should be no higher than 135 to 175\ 250 psi ouch if the pressure is this high the condenser may be restriced or the receiver dyer has interaly come apart cloging the system dose the low or suckion side get cold and frost up when charged low side psi should be 35 \55 psi max also disconect the condenser lines and blow the condenser out with compressed air high pressure 150 psi also blow out the evaparator core sounds sounds like you have a restrictin or a crimped line in your system if you pull the system down with vacum and hear a knock or a thud somthing is in there that shouldint be there good luck bill
08-08-2011, 05:40 PM
#10
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Join Date: Jul 2007
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I currently have AC dye already in the system. My Snap on freon leak detector has a U/V light with it, and neither method has shown me any leaks, so its gotta be the one thing I can't see or let my sniffer sniff.
Bill. I have converted the system over to r134a, as I am not fully certified to be able to buy r12. Although I got an A in all my auto classes in college, I never took the time to get certified, and I dont know were to take the test.
I think I am going to go ahead and changed the evap out. But I was wondering whatever one's opinion is on what brand I should go with. Rockauto has four seasons for 83 dollars, and spectra premium for 91 dollars. I dont mind spending a couple of extra dollars if spectra is good. But says they have only 1 remaining, which leads me to think rockauto is gonna stop carrying it from them cause they are bad.
So four seasons or spectra, what does everyone think?
Bill. I have converted the system over to r134a, as I am not fully certified to be able to buy r12. Although I got an A in all my auto classes in college, I never took the time to get certified, and I dont know were to take the test.
I think I am going to go ahead and changed the evap out. But I was wondering whatever one's opinion is on what brand I should go with. Rockauto has four seasons for 83 dollars, and spectra premium for 91 dollars. I dont mind spending a couple of extra dollars if spectra is good. But says they have only 1 remaining, which leads me to think rockauto is gonna stop carrying it from them cause they are bad.
So four seasons or spectra, what does everyone think?