RE-doing my a/c system, a few questions
06-22-2010, 06:37 PM
#1
RE-doing my a/c system, a few questions
Hey guys, A/C is working okay now, i have a hint i have some oxygen in my system, it's been awhile but my low side readings were a bit high, and high side readings were a bit low. Initial startup of the motor and a/c, the temp isn't very cold until i've been driving around for a bit, doesn't matter the speed as long as the a/c has been on for awhile. Usually it gets quite a bit warmer at stoplights and stuff (understandable) but any suggestions before I vacuum the system and use my new drier?
I bought a new drier from Honda,which i'm going to replace after i vacuum the system, replace the drier. Then fill the system with freon.
http://www.oreillyauto.com/site/c/se...1783/C0050.oap
Out of all the different brands, which brand freon do you recommend?
This is going into a 99 civic EX.
I bought a new drier from Honda,which i'm going to replace after i vacuum the system, replace the drier. Then fill the system with freon.
http://www.oreillyauto.com/site/c/se...1783/C0050.oap
Out of all the different brands, which brand freon do you recommend?
This is going into a 99 civic EX.
06-22-2010, 07:49 PM
#2
Honda-Tech Member
Re: RE-doing my a/c system, a few questions
is the condenser fan on?
is it undercharged?
compresser could be on the way out the door as well, seen this miss diaged a lot only reason i'm asking.
if the dryer came apart you need more than just a dryer
is it undercharged?
compresser could be on the way out the door as well, seen this miss diaged a lot only reason i'm asking.
if the dryer came apart you need more than just a dryer
06-23-2010, 08:44 AM
#3
Re: RE-doing my a/c system, a few questions
Everything works correctly. the weather seems to play a big role in whether the ac works good or not. The reason why i bought a new dryer is cuz' i'm gonna vacuum the system and put new freon in it, mine as well get some added insurance and make sure a new dryer is in there to keep all the moisture out.
Whenever i had the gauges on there, it showed the system was full and we put an extra ounce in there just to see what would happen. nothing changed
06-23-2010, 06:04 PM
#4
Honda-Tech Member
Re: RE-doing my a/c system, a few questions
when you crack the lines open look in them right out of the compressor or the dryer and look for symptoms of the infamous black death.
if the system is full and condenser fan comes on and the dryer didn't come apart it would lead me more to the compressor
if the system is full and condenser fan comes on and the dryer didn't come apart it would lead me more to the compressor
06-24-2010, 06:15 PM
#6
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Re: RE-doing my a/c system, a few questions
Black death, just what it sounds like, if, once you pull a line, what comes out is black you have black death.
There is no reason to replace the accumulator, [filter/dryer] unless it is damaged in some way, an hour on a vacuum pump will remove any moisture in the system.
Of the DIY cans you link, use only the one that is 100% R134a refrigerant with no additives of any kind, good luck finding one.
You said, "the system was full and we put an extra ounce in there just to see what would happen" an ounce of what exactly?
A low high side with a high low side pressure is either the compressor on it's way out, [as mentioned] or a defective expansion valve, [stuck open/not closing properly].
What are the high and low side PSIs with engine running at 2000 RPM, what is the vent temperature?
Although there are a number of factors that have an effect on high and low PSIs, like ambient temp. humidity even altitude, not to mention system issues, refrigerant charge, compressor and expansion valve condition, air flow and so on, look for the "30/150" PSIs about 30 on the low side and about 150 on the high side, low side dropping below 15 indicates a low charge, head pressures, [high side] of over 200 indicate an overcharge or poor air flow through condenser.
These pressures can vary up or down quit bit and still produce acceptable vent temperatures.
We look for 8 degrees C, [or better] from the vents within 2-3 min. of turning A/C on, @ idle with high side PSI of no more then 150, [200 on diesel engines] low side PSIs of no less then 15 with condenser fan turning on at no more then 175 PSI on the high side, [225 PSI on diesel engines] with compressor cycling off every few min.
http://airwolfeautoair.com/ 94
There is no reason to replace the accumulator, [filter/dryer] unless it is damaged in some way, an hour on a vacuum pump will remove any moisture in the system.
Of the DIY cans you link, use only the one that is 100% R134a refrigerant with no additives of any kind, good luck finding one.
You said, "the system was full and we put an extra ounce in there just to see what would happen" an ounce of what exactly?
A low high side with a high low side pressure is either the compressor on it's way out, [as mentioned] or a defective expansion valve, [stuck open/not closing properly].
What are the high and low side PSIs with engine running at 2000 RPM, what is the vent temperature?
Although there are a number of factors that have an effect on high and low PSIs, like ambient temp. humidity even altitude, not to mention system issues, refrigerant charge, compressor and expansion valve condition, air flow and so on, look for the "30/150" PSIs about 30 on the low side and about 150 on the high side, low side dropping below 15 indicates a low charge, head pressures, [high side] of over 200 indicate an overcharge or poor air flow through condenser.
These pressures can vary up or down quit bit and still produce acceptable vent temperatures.
We look for 8 degrees C, [or better] from the vents within 2-3 min. of turning A/C on, @ idle with high side PSI of no more then 150, [200 on diesel engines] low side PSIs of no less then 15 with condenser fan turning on at no more then 175 PSI on the high side, [225 PSI on diesel engines] with compressor cycling off every few min.
http://airwolfeautoair.com/ 94
06-24-2010, 08:36 PM
#7
Re: RE-doing my a/c system, a few questions
Black death, just what it sounds like, if, once you pull a line, what comes out is black you have black death.
There is no reason to replace the accumulator, [filter/dryer] unless it is damaged in some way, an hour on a vacuum pump will remove any moisture in the system.
Of the DIY cans you link, use only the one that is 100% R134a refrigerant with no additives of any kind, good luck finding one.
You said, "the system was full and we put an extra ounce in there just to see what would happen" an ounce of what exactly?
A low high side with a high low side pressure is either the compressor on it's way out, [as mentioned] or a defective expansion valve, [stuck open/not closing properly].
What are the high and low side PSIs with engine running at 2000 RPM, what is the vent temperature?
Although there are a number of factors that have an effect on high and low PSIs, like ambient temp. humidity even altitude, not to mention system issues, refrigerant charge, compressor and expansion valve condition, air flow and so on, look for the "30/150" PSIs about 30 on the low side and about 150 on the high side, low side dropping below 15 indicates a low charge, head pressures, [high side] of over 200 indicate an overcharge or poor air flow through condenser.
These pressures can vary up or down quit bit and still produce acceptable vent temperatures.
We look for 8 degrees C, [or better] from the vents within 2-3 min. of turning A/C on, @ idle with high side PSI of no more then 150, [200 on diesel engines] low side PSIs of no less then 15 with condenser fan turning on at no more then 175 PSI on the high side, [225 PSI on diesel engines] with compressor cycling off every few min.
http://airwolfeautoair.com/ 94
There is no reason to replace the accumulator, [filter/dryer] unless it is damaged in some way, an hour on a vacuum pump will remove any moisture in the system.
Of the DIY cans you link, use only the one that is 100% R134a refrigerant with no additives of any kind, good luck finding one.
You said, "the system was full and we put an extra ounce in there just to see what would happen" an ounce of what exactly?
A low high side with a high low side pressure is either the compressor on it's way out, [as mentioned] or a defective expansion valve, [stuck open/not closing properly].
What are the high and low side PSIs with engine running at 2000 RPM, what is the vent temperature?
Although there are a number of factors that have an effect on high and low PSIs, like ambient temp. humidity even altitude, not to mention system issues, refrigerant charge, compressor and expansion valve condition, air flow and so on, look for the "30/150" PSIs about 30 on the low side and about 150 on the high side, low side dropping below 15 indicates a low charge, head pressures, [high side] of over 200 indicate an overcharge or poor air flow through condenser.
These pressures can vary up or down quit bit and still produce acceptable vent temperatures.
We look for 8 degrees C, [or better] from the vents within 2-3 min. of turning A/C on, @ idle with high side PSI of no more then 150, [200 on diesel engines] low side PSIs of no less then 15 with condenser fan turning on at no more then 175 PSI on the high side, [225 PSI on diesel engines] with compressor cycling off every few min.
http://airwolfeautoair.com/ 94
My buddy's shop has the big 30 pound (i think? it's the big r-134 bottles you buy as a licensed "professional" from autozone/o'reillys/napa) that's just pure r134 right?
My instructor and I just added an extra ounce of freon, that too was in the enormous industrial can on the snap-on a/c service machine.
The two a/c people i've talked to have told me the symptoms i have either indicate i have 1.oxygen/moisture in my system. or 2. a defective thermal expansion valve, which both told me to replace. Question is, I've heard it's a bitch to do on EK civics. Any writeups on how to?
Also, today i noticed I've been driving with adequate airflow to the condensor at about 3-3500 rpm in 5th gear, and suddenly the air felt like it got 5-10 degrees cooler. Is there a possibility there's something lodged in the TIV, and it gets unclogged then the system blows cooler? I've had the same symptoms for the last 2.5 years. A/c system doesn't seem to be getting weaker or anything
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06-25-2010, 04:43 AM
#8
Honda-Tech Member
Re: RE-doing my a/c system, a few questions
we need to see pressures to put you inthe correct direction at idle and at 2000 rpm please pressures are everything when it comes to a/c diag
06-25-2010, 06:18 AM
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Re: RE-doing my a/c system, a few questions
Well good for you, [adding the once of "real" R134a] your system is probably not contaminated like most of the cars the DIYs have on this form [I assume your buddy "identified" your system before he connected up the SnapOn machine].
I agree with both the A/C "people you spoke with, it can be either moisture or the expansion valve, more then likely the expansion valve because, "and suddenly the air felt like it got 5-10 degrees cooler" a sure symptom of a sticky expansion valve.
Yes, unfortunatly not one of Hondas best ideas, installing the expansion valve inside the heater/evap. box.
If I remember correctly it's not that hard to access, but I will have to check, but I think the evaporator can be removed without pulling the dash and heater box, pull the glove box to access the bolts that hold evap. housing in place, with no A/C there would be a piece of duct where evap housing is, between heater box and blower motor housings. 94
I agree with both the A/C "people you spoke with, it can be either moisture or the expansion valve, more then likely the expansion valve because, "and suddenly the air felt like it got 5-10 degrees cooler" a sure symptom of a sticky expansion valve.
Yes, unfortunatly not one of Hondas best ideas, installing the expansion valve inside the heater/evap. box.
If I remember correctly it's not that hard to access, but I will have to check, but I think the evaporator can be removed without pulling the dash and heater box, pull the glove box to access the bolts that hold evap. housing in place, with no A/C there would be a piece of duct where evap housing is, between heater box and blower motor housings. 94
06-25-2010, 06:38 AM
#11
Re: RE-doing my a/c system, a few questions
Well good for you, [adding the once of "real" R134a] your system is probably not contaminated like most of the cars the DIYs have on this form [I assume your buddy "identified" your system before he connected up the SnapOn machine].
I agree with both the A/C "people you spoke with, it can be either moisture or the expansion valve, more then likely the expansion valve because, "and suddenly the air felt like it got 5-10 degrees cooler" a sure symptom of a sticky expansion valve.
Yes, unfortunatly not one of Hondas best ideas, installing the expansion valve inside the heater/evap. box.
If I remember correctly it's not that hard to access, but I will have to check, but I think the evaporator can be removed without pulling the dash and heater box, pull the glove box to access the bolts that hold evap. housing in place, with no A/C there would be a piece of duct where evap housing is, between heater box and blower motor housings. 94
I agree with both the A/C "people you spoke with, it can be either moisture or the expansion valve, more then likely the expansion valve because, "and suddenly the air felt like it got 5-10 degrees cooler" a sure symptom of a sticky expansion valve.
Yes, unfortunatly not one of Hondas best ideas, installing the expansion valve inside the heater/evap. box.
If I remember correctly it's not that hard to access, but I will have to check, but I think the evaporator can be removed without pulling the dash and heater box, pull the glove box to access the bolts that hold evap. housing in place, with no A/C there would be a piece of duct where evap housing is, between heater box and blower motor housings. 94
But at my buddy's shop, he won't charge me for freon and he just "guesstimates" how much freon goes into a system. it's just the bottle with the highside fitting. How do you know how much freon to add if you don't have a scale or anything? Go off gauges? That's what he mainly does
06-25-2010, 05:52 PM
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Re: RE-doing my a/c system, a few questions
The only way to get the correct amount of refrigerant into the system is with a charge cylinder... http://www.sjdiscounttools.com/rob34205a.html, we have 3 of these, or the machine... http://www.sjdiscounttools.com/rob34700z.html we have one of these.
If your good you can get close by "guesstimating" and using a proper set of gauges... http://buy1.snapon.com/catalog/item....re&dir=catalog we have a number of these and an R12 set and a good thermostat, however without weighing or measuring how much you are putting in, it is just a guess, an educated guess maybe, but still a guess.
I know of no "tutorial" for removing the evaporator, but as I said and if I remember correctly it is pretty easy on a Civic...
Remove glove box, remove glove box "cross bar" to acces the four, [I think] 10mm bolt/screws to remove evap. case, the refrigerant must be recovered and the piping disconnected at the engine bay fire wall, pull evap. case out.
It's been a while since I did one so I am not positive the above is correct, but it will be obvious to you once you remove the glove box, I will try and check at work to see if we have anything. 94
If your good you can get close by "guesstimating" and using a proper set of gauges... http://buy1.snapon.com/catalog/item....re&dir=catalog we have a number of these and an R12 set and a good thermostat, however without weighing or measuring how much you are putting in, it is just a guess, an educated guess maybe, but still a guess.
I know of no "tutorial" for removing the evaporator, but as I said and if I remember correctly it is pretty easy on a Civic...
Remove glove box, remove glove box "cross bar" to acces the four, [I think] 10mm bolt/screws to remove evap. case, the refrigerant must be recovered and the piping disconnected at the engine bay fire wall, pull evap. case out.
It's been a while since I did one so I am not positive the above is correct, but it will be obvious to you once you remove the glove box, I will try and check at work to see if we have anything. 94
06-26-2010, 10:46 PM
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Re: RE-doing my a/c system, a few questions
Funniest thing. I just re did my expansion valve in my EG hatch. It sits behind the glove box. I tell you though no A/C sux and i will spend the dollars to make it work...
Once you get the box out you just seperate it and do your business. I spent about 3 hours cleaning / redoing it. Yrs of filth down in there.
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/c-leak-much-pressure-2790980/
Once you get the box out you just seperate it and do your business. I spent about 3 hours cleaning / redoing it. Yrs of filth down in there.
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/c-leak-much-pressure-2790980/
06-29-2010, 08:16 AM
#16
Re: RE-doing my a/c system, a few questions
ALso, whenever I vacuum everything out of my system for an hour, do I just go ahead and unbolt everything. or how do i let the pressure in the system equalize with the atmosphere so it doesn't suction hardcore when i open the system up to replace my expansion valve?
06-29-2010, 10:48 AM
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Re: RE-doing my a/c system, a few questions
Just start taking it apart. After i purged my system for 30 min or so. i was ready to disassemble any component. Remember when u take apart the evap box to seal around hose connections. Look at my clean up and you'll see the masking tape. That is because i cleaned my evap in the sink with some soap and water and didn't want to get foreign fluid in there. Not sure if it matters but i did it. My setup is still original @ 19 yrs old and caution needs to be taken....
06-29-2010, 05:08 PM
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Re: RE-doing my a/c system, a few questions
The system should not be under vacuum before removing/undoing anything, recover any refrigerant still in the system, then disconnect the evap. lines and remove the evaporator.
Any connection that you disconnect should be plugged to prevent anything from getting into the system, replace O rings, [no matter how good they look] of any connection you disconnect, use a little C4 oil on the O rings when reconnecting, it will help the rings seat themselves properly and prevent damage to them, a dry O ring can easily be damaged. 94
Any connection that you disconnect should be plugged to prevent anything from getting into the system, replace O rings, [no matter how good they look] of any connection you disconnect, use a little C4 oil on the O rings when reconnecting, it will help the rings seat themselves properly and prevent damage to them, a dry O ring can easily be damaged. 94
06-30-2010, 04:19 AM
#19
Re: RE-doing my a/c system, a few questions
Just start taking it apart. After i purged my system for 30 min or so. i was ready to disassemble any component. Remember when u take apart the evap box to seal around hose connections. Look at my clean up and you'll see the masking tape. That is because i cleaned my evap in the sink with some soap and water and didn't want to get foreign fluid in there. Not sure if it matters but i did it. My setup is still original @ 19 yrs old and caution needs to be taken....
06-30-2010, 05:41 AM
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Re: RE-doing my a/c system, a few questions
He replaced his expansion valve... http://www.thepartsbin.com/images/pr...sons/38631.jpg a critical part of an A/C system, it must work properly at all times for A/C to function. 94
06-30-2010, 09:28 AM
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Re: RE-doing my a/c system, a few questions
if you click on my post above. You'll see i changed the safety valve on the a/c compressor first. Got it all filled up and the system was pulling a vacuum. Concluded the expansion valve was stuck / having issues, so that was replaced, per my post. A/C is worky, lol but marginal. Going under the knife again today for further examination. Should be posting some data in my thread above.
07-02-2010, 02:50 PM
#22
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Re: RE-doing my a/c system, a few questions
fcm has given perfect advice. If I was going to guess at the amount of freon I was adding, I use a nice thermometer in the vent to monitor output temperature at 1500 RPM, I continue to add until I get the lowest temp and then a small rise in temp, this means I just put a hair too much gas in. As fcm mentioned, you have to monitor your gauge set for pressures too. I do this slowly to allow the gas time to get around the system completely. More commonly referred to as a Top Off.
From your explanation of the air getting colder as you drive, low HI side pressure and high LO side pressure, I would first think there is not enough freon. Another time you made it sound as though the temp jumped cooler one time which could be the TEV. I would add more gas an ounce at a time to try to get pressures closer to what fcm stated, 30 and 150 and colder vent temps.
You also need to learn to bleed the hose with freon prior to final tightening onto your service valve to push all the atmospheric air out of the hose so it does not get into your system. Your TEV has to be installed correctly also, there is a lot of theory of how these things work best. If you get in there to do maintenance, see if there is one indentation on the metal line where the TEV is located, more to come on that later.
From your explanation of the air getting colder as you drive, low HI side pressure and high LO side pressure, I would first think there is not enough freon. Another time you made it sound as though the temp jumped cooler one time which could be the TEV. I would add more gas an ounce at a time to try to get pressures closer to what fcm stated, 30 and 150 and colder vent temps.
You also need to learn to bleed the hose with freon prior to final tightening onto your service valve to push all the atmospheric air out of the hose so it does not get into your system. Your TEV has to be installed correctly also, there is a lot of theory of how these things work best. If you get in there to do maintenance, see if there is one indentation on the metal line where the TEV is located, more to come on that later.
07-02-2010, 03:44 PM
#23
Re: RE-doing my a/c system, a few questions
^^ wow, good info. could you care to explain how to bleed the service hose prior to filling my system up with freon? I'm going to order a TEV come monday, and do a complete overhaul. I'm sure my compressor works fine. The system has had the same symptoms for 2 1/2 years i've had the car so i'm sure the compressor is working fine. Thanks a bunch guys
07-03-2010, 05:49 AM
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Re: RE-doing my a/c system, a few questions
I had a bad thermal safety switch. I initially thought it was from my oil-gunked condensor (previous owners blew 3 motors in that car, always rod #1 or #2). I figured it out after I followed helm's troubleshooting flowchart. This was making the clutch disengage constantly, as it senses the heat of the compressor (small wired puck on top near hoses). I still have to check pressures to see if that expansion valve is bad, but it works FAR better when the compressor stays turning.
07-03-2010, 10:28 AM
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Re: RE-doing my a/c system, a few questions
[QUOTE=ohsnapzafingcu;42922665]^^ wow, good info. could you care to explain how to bleed the service hose prior to filling my system up with freon? I'm going to order a TEV come monday, and do a complete overhaul. I'm sure my compressor works fine. The system has had the same symptoms for 2 1/2 years i've had the car so i'm sure the compressor is working fine. Thanks a bunch guys[/
I guess it depends on what type of servicing hoses you have, screw on type like R12, screw on a couple of threads to your service port, open the valve on the tank of freon, let the freon leak out of the loose connection to push the air out of the hose, while it is leaking, tighten the hose connection to the service port and start servicing, if you are servicing a freshly vacuumed system, same procedure applies for the HI side.
If you have R134a type fittings, there are different styles there too. You may have to push the valve in the end of the fitting with a small blunt object, careful not to damage it, you should wear a glove as to not spray freon on your hand and dont aim it at your face. Just a couple of seconds is enough.
Do you get the idea of purging the air out of the hose prior to final connection to the service port on the car. This of course only applies to DIY folks who do not have a nice AC recovery/recycle machine, this works for freon tanks and small cans alike. The pros know this is not allowed as it kills the ozone layer over our heads.
I guess it depends on what type of servicing hoses you have, screw on type like R12, screw on a couple of threads to your service port, open the valve on the tank of freon, let the freon leak out of the loose connection to push the air out of the hose, while it is leaking, tighten the hose connection to the service port and start servicing, if you are servicing a freshly vacuumed system, same procedure applies for the HI side.
If you have R134a type fittings, there are different styles there too. You may have to push the valve in the end of the fitting with a small blunt object, careful not to damage it, you should wear a glove as to not spray freon on your hand and dont aim it at your face. Just a couple of seconds is enough.
Do you get the idea of purging the air out of the hose prior to final connection to the service port on the car. This of course only applies to DIY folks who do not have a nice AC recovery/recycle machine, this works for freon tanks and small cans alike. The pros know this is not allowed as it kills the ozone layer over our heads.
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