The 02 Accord isn't exactly blowing ice cubes any more. That, along with it being 7 years old and 192K miles, probably means it's a little low on refrigerant. A while ago, I came across and article that said not to use any 134a with "stop leak" stuff in them. It claimed that could foul up your AC system. However, I have looked and looked, but it seems like all auto 134a's have some sort of stop leak stuff in them. Also, I'm wondering if I really need to get a low pressure guage. I remember Dad and I just adding refrigerant with the can and the hose into it until it started blowing cooler, usually a can and maybe two, at max. Since most systems hold about 3 to 4 cans, I figure one can would be enough. Anyway, anybody got anything on using a 134a with "stop leak" stuff in it?
Adding 134a refrigerant
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You need to be careful when adding R134a, you can add too much.
Several years ago a battery acid leak ate a hole through the steel A/C line on my car. I took it off and soldered a patch onto it and refilled the system. My A/C compressor would engage and disengage because the pressure sensor would detect that the coolant level was low. I hooked the can back up and started adding more coolant to the system. The gauge didn't read any extra pressure in the system, so I started the car up and turned on the A/C. The compressor sounded like it was chewing up kittens, so I put the hose back on and checked the pressure. It was about 4x what it was supposed to have in it. I had to let a bunch back out, which was messy since I had added an ester charge to the system. It still sounded pretty bad for a few months, and the compressor actually made a loud thunk when it engaged. Thankfully, it seems to have stopped doing that.
Several years ago a battery acid leak ate a hole through the steel A/C line on my car. I took it off and soldered a patch onto it and refilled the system. My A/C compressor would engage and disengage because the pressure sensor would detect that the coolant level was low. I hooked the can back up and started adding more coolant to the system. The gauge didn't read any extra pressure in the system, so I started the car up and turned on the A/C. The compressor sounded like it was chewing up kittens, so I put the hose back on and checked the pressure. It was about 4x what it was supposed to have in it. I had to let a bunch back out, which was messy since I had added an ester charge to the system. It still sounded pretty bad for a few months, and the compressor actually made a loud thunk when it engaged. Thankfully, it seems to have stopped doing that.
All I can say is, I killed the A/C in my car by adding R134A with leak sealer because it "wasn't blowing ice cubes" anymore! I added a little, it still wasn't cold (to my tastes), so I added a little more, then a little more - finally, it was hardly blowing any cold air. I took it to a pro, and it was so overfilled it was about to explode.
My :2cents: : stick a thermometer in the center vent, put the system on high with all the windows down, and get the rpms to 1,500 to 2,000 rpm. Vent temps should be 35 to 40 below ambient - roughly 45 to 50 degrees - if it's like 110 degrees out with 100% humidity, 55 to 60 would be a normal vent temp.
If it's not cooling to at least 50 degrees, take it to a professional and have the system evacuated and recharged by weight. That way you'll know it's perfect, and it only costs roughly $100.
Chris142, the resident A/C and cooling system mistro will say the exact same thing!
My :2cents: : stick a thermometer in the center vent, put the system on high with all the windows down, and get the rpms to 1,500 to 2,000 rpm. Vent temps should be 35 to 40 below ambient - roughly 45 to 50 degrees - if it's like 110 degrees out with 100% humidity, 55 to 60 would be a normal vent temp.
If it's not cooling to at least 50 degrees, take it to a professional and have the system evacuated and recharged by weight. That way you'll know it's perfect, and it only costs roughly $100.
Chris142, the resident A/C and cooling system mistro will say the exact same thing!
Not all R-134a has stop-leak. Look for Dupont SUVA for one, its pure 134a.
Recharging a 134a system is NOT as easy as the old "put more in until the sight glass is clear or the suction line is cool" way of charging R12. There are 2 ways to correctly charge an R-134a system:
1) pull a vacuum and put in the recommended weight of refrigerant.
2) Put a manifold gauge set on the system so you can monitor high-side and low-side pressures. You also need a thermometer on the liquid line, and an R-134a charge chart (found in most car service manuals, or look online probably). You then note the liquid line temp, then look at the chart to see what the high side pressure should be- if its low, add until you get in the zone. Note that the liquid line temp will change as you do this, so you gotta keep referring back to the chart.
I will 'fess up to having cheated and "guesstimated" the liquid line temp by hand (if you can barely hold onto it, its around 120 degrees. If you can hold it 10 seconds and then can't stand it, its around 140). It worked fine for me, but I don't recommend it.
Recharging a 134a system is NOT as easy as the old "put more in until the sight glass is clear or the suction line is cool" way of charging R12. There are 2 ways to correctly charge an R-134a system:
1) pull a vacuum and put in the recommended weight of refrigerant.
2) Put a manifold gauge set on the system so you can monitor high-side and low-side pressures. You also need a thermometer on the liquid line, and an R-134a charge chart (found in most car service manuals, or look online probably). You then note the liquid line temp, then look at the chart to see what the high side pressure should be- if its low, add until you get in the zone. Note that the liquid line temp will change as you do this, so you gotta keep referring back to the chart.
I will 'fess up to having cheated and "guesstimated" the liquid line temp by hand (if you can barely hold onto it, its around 120 degrees. If you can hold it 10 seconds and then can't stand it, its around 140). It worked fine for me, but I don't recommend it.
Well, it was a hot day yesterday and there were 4 of us in the car. I haven't driven it in a while, maybe it's me. But, I do have a good thermometer and I'll check the blowing temperature reading in the vents first before I do anything. Thanks for the ideas and tips.
It has a leak somewhere, I would think. My '99 S-10 is hardly used, and still fully charged.
Just adding refrigerant is pretty imprecise, and if air has leaked into the system, you will probably wind up with way too much pressure, not that I haven't done it. The better way is to vaccuum down the system, and refill it with the correct weight of refrigerant. Gauges are really helpful, but if you put the correct weight back in, it should work well enough. It seems most modern systems only take maybe a pound or pound and a half of juice these days.
I got one of those cheesy venturi type vaccuum pumps from HF, and rigged some fittings unto it to vaccuum, but it takes a big compressor to pull and hold (-) 30 inches on it.
I think the general prohibition against stop leak is so that some of the finer orifices in some systems don't get plugged. Somebody on here is probably an AC professional.
BTW, Atwoods has R134A for $4.99/ can this week.
Just adding refrigerant is pretty imprecise, and if air has leaked into the system, you will probably wind up with way too much pressure, not that I haven't done it. The better way is to vaccuum down the system, and refill it with the correct weight of refrigerant. Gauges are really helpful, but if you put the correct weight back in, it should work well enough. It seems most modern systems only take maybe a pound or pound and a half of juice these days.
I got one of those cheesy venturi type vaccuum pumps from HF, and rigged some fittings unto it to vaccuum, but it takes a big compressor to pull and hold (-) 30 inches on it.
I think the general prohibition against stop leak is so that some of the finer orifices in some systems don't get plugged. Somebody on here is probably an AC professional.
BTW, Atwoods has R134A for $4.99/ can this week.
I bought a vacuum motor and a set of manifold gauges, so I could more accurately do some for my friends. Mainly I bought them because I found the leak on my 92 legacy, and after a new condenser (leak) and a new drier, I'm now rocking R134a 
and working AC I think it could be a little colder, but I think I might have used a touch too much oil. I had converted it before winter before I knew I had the leak. I had 6oz of Ester (compatible with r12 oil and yes I dumped the old oil from compressor.) in there, but when the refridgerant leaked out, I imagine I lost some oil too. I ended up putting another 2oz of oil in when I pulled it down. I think I ended up using around 90% of the original r12 filling capcity as was recommended on the net.
I did my brothers newer Jimmy also. His was just low on r134a. I pulled vacuum on it for 30 minutes and sat for 10 and no drop in vacuum.
I didn't know you measure temp of liquid line. I was wondering how they came up with 300 psi on the high side with XX ambient temp. Highest my brother's Jimmy went to was 200psi.
and working AC I think it could be a little colder, but I think I might have used a touch too much oil. I had converted it before winter before I knew I had the leak. I had 6oz of Ester (compatible with r12 oil and yes I dumped the old oil from compressor.) in there, but when the refridgerant leaked out, I imagine I lost some oil too. I ended up putting another 2oz of oil in when I pulled it down. I think I ended up using around 90% of the original r12 filling capcity as was recommended on the net.I did my brothers newer Jimmy also. His was just low on r134a. I pulled vacuum on it for 30 minutes and sat for 10 and no drop in vacuum.
I didn't know you measure temp of liquid line. I was wondering how they came up with 300 psi on the high side with XX ambient temp. Highest my brother's Jimmy went to was 200psi.
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There should ba a sticker under the hood that tells the capacity. You need to check that before you add 3 or 4 cans! R134a is a much different animal than the old R12 was where close was good enough.
I'd guess that your car holds about 24oz total.
Before you go goofing with it start it and turn the AC on high. Open the hood and find the larger AC suction hose/line. It should be cold.
If it's cold then the charge is probly ok. Check the heater hoses. Your car should have a heater control valve and when they go bad they allow hot water to heat up the cold AC.
If the line is not cold then we need a high side pressure reading to properly charge the system. Cant do it with just a low side guage.
I'd guess that your car holds about 24oz total.
Before you go goofing with it start it and turn the AC on high. Open the hood and find the larger AC suction hose/line. It should be cold.
If it's cold then the charge is probly ok. Check the heater hoses. Your car should have a heater control valve and when they go bad they allow hot water to heat up the cold AC.
If the line is not cold then we need a high side pressure reading to properly charge the system. Cant do it with just a low side guage.
Originally Posted By: Buffman
I was wondering how they came up with 300 psi on the high side with XX ambient temp. Highest my brother's Jimmy went to was 200psi.
High side pressure should be 2.0- 2.2 times the ambient air temp.
I was wondering how they came up with 300 psi on the high side with XX ambient temp. Highest my brother's Jimmy went to was 200psi.
High side pressure should be 2.0- 2.2 times the ambient air temp.
Well, on ya'lls advice, I decided to test the actual temperature coming off the vents with the AC on high and on recirc. mode. Ambient temperature was 84 degrees and the lowest recording got coming out of the vents was 47. So, it's obviously not the system. May be time to clean the coils and check the fans.
Maybe that day you were just stressed a bit, plus with 4 people in the car, that's a lot of additional heat that takes time to cool off. Was it just a short drive?
I've always thought that another telltale sign that the A/C is OK, is when you have it one for a long enough time, you'll get to the point where you need to turn it down. ie. on a longer drive. That, and the system will get cold enough where the compressor will cycle on and off.
I bet it's just fine on your Accord.
If you want to take the time and effort, one way to restore A/C capacity is to reverse flush the condenser. You'll have to take the rad fans out and anything else that's in the way (fan shroud etc.), but the front of the compressor in a 200K mile car is probably loaded with dead bugs and pebbles. After it's cleaned out, take about an hour and try and straighten out the majority of the bent fins. Just doing that will likely increase A/C performance. It has on the cars I've done it to.
I've always thought that another telltale sign that the A/C is OK, is when you have it one for a long enough time, you'll get to the point where you need to turn it down. ie. on a longer drive. That, and the system will get cold enough where the compressor will cycle on and off.
I bet it's just fine on your Accord.
If you want to take the time and effort, one way to restore A/C capacity is to reverse flush the condenser. You'll have to take the rad fans out and anything else that's in the way (fan shroud etc.), but the front of the compressor in a 200K mile car is probably loaded with dead bugs and pebbles. After it's cleaned out, take about an hour and try and straighten out the majority of the bent fins. Just doing that will likely increase A/C performance. It has on the cars I've done it to.
You got that right, stressed out...the people were: my 5 year old daughter, my wife and her mother.....suprised I didn't try and shoot myself....
One other thing, and you are spot on, is that the front of the condensor has a lot of bent fins. I've seen a fin "straightner-upper" at some of the stores around here, maybe I ought to get one. Thanks, I didn't even think of that. After getting on the highway, it did cool down more, just not as fast as I remember it to....but with a black car, light tint, all vents aimed in the back to cool them off, high himidity and about 95 degrees plus, I guess I should just shut up....Thanks for the help.
One other thing, and you are spot on, is that the front of the condensor has a lot of bent fins. I've seen a fin "straightner-upper" at some of the stores around here, maybe I ought to get one. Thanks, I didn't even think of that. After getting on the highway, it did cool down more, just not as fast as I remember it to....but with a black car, light tint, all vents aimed in the back to cool them off, high himidity and about 95 degrees plus, I guess I should just shut up....Thanks for the help.
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I tried using one of those fin straighteners. Piece of garbage IMO. I used a small flathead screwdriver. Takes forever, but works better IMO. Just be gentle and don't brake the fins or puncture the core.
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+1 to cleaning out the radiator and condenser.
You would be amazed at how much junk comes out when you flush it out. Not just bugs, but literal dirt. Especially on a car with that many miles, if its never been flushed before I can guarantee the radiator has a large hairball on the front and is full junk. As soon as you start hosing it out the water running out will be brown for awhile. Keep flushing until it runs clear.
After your done, the A/C will work better, the fans will cycle less, and the engine temp will drop 5-10 degrees. Every time I do a cooling system service (replace antifreeze) I flush em out, and it's always full of junk.
Do that first, then see how cold it blows. If it's still warm, then start looking at refrigerant charge. Keep in mind on a hot day, with a heated up dash from sitting outside, it may take 10 or more minutes of driving for the A/C to blow cold. Make sure temp setting is on "LOW" or "60" and "RECIRCULATE" is ON.
You would be amazed at how much junk comes out when you flush it out. Not just bugs, but literal dirt. Especially on a car with that many miles, if its never been flushed before I can guarantee the radiator has a large hairball on the front and is full junk. As soon as you start hosing it out the water running out will be brown for awhile. Keep flushing until it runs clear.
After your done, the A/C will work better, the fans will cycle less, and the engine temp will drop 5-10 degrees. Every time I do a cooling system service (replace antifreeze) I flush em out, and it's always full of junk.
Do that first, then see how cold it blows. If it's still warm, then start looking at refrigerant charge. Keep in mind on a hot day, with a heated up dash from sitting outside, it may take 10 or more minutes of driving for the A/C to blow cold. Make sure temp setting is on "LOW" or "60" and "RECIRCULATE" is ON.
The only correct way to add refrigerant is to have it done professionally. You really need to evacuate the system and add only the correct amount of refrigerant.
Of course, there are some people who do not strive for perfection, so I guess that "guesstimating" works for them. But for those of us who want optimal performance, then having it done professionally with a machine is the only way of guaranteeing good results.
Remember, having it done professionally isn't that expensive. It's usually around $100, sometimes even less at places such as Pep Boys.
Of course, there are some people who do not strive for perfection, so I guess that "guesstimating" works for them. But for those of us who want optimal performance, then having it done professionally with a machine is the only way of guaranteeing good results.
Remember, having it done professionally isn't that expensive. It's usually around $100, sometimes even less at places such as Pep Boys.
Critic: Some how "professional" and Pep Boys don't seem to go in the same sentence.
Roger on use both hands
Roger on use both hands
Yeah I would agree, but a professional evac and recharge at a dealer around here was only $120. I will have it professionally done on cars I care about. But my subaru, I did it myself.
The only time I've used Pep Boys for repair work they did an excellent job. They were the only place open. I was in Louisiana, about 200 miles from home, on a Sunday afternoon, and got a nail in one of my Z4's run flat tires. They removed the tire, patched the hole and put everything back together without damaging the rim.
Originally Posted By: Smoky14
Critic: Some how "professional" and Pep Boys don't seem to go in the same sentence.
Roger on use both hands
My local Pep Boys (back home) is outstanding. I would not hesitate to go there. Not all chain auto repair shops are bad, it really varies by location.
Critic: Some how "professional" and Pep Boys don't seem to go in the same sentence.
Roger on use both hands
My local Pep Boys (back home) is outstanding. I would not hesitate to go there. Not all chain auto repair shops are bad, it really varies by location.
Our Pep Boys were terrible. Luckily we don't have them around anymore. I don't have a problem with a person adding a can or two themselves. For many people though $100. is a lot of money to spend and many times a place will come back saying you need this that and the other and before you know it it has become quite a bit higher.
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