DCFIVER

That is not how you measure pressures on that model year Civic. Wrong again stud.
Wrong. High side pressure directly correlates to ambient temperature. 200-250 psi is quite common for 95-100 temperatures. 250 is somewhat high but not uncommon on hot days, especially on large systems.
You are. The sad part is you dont even realize it. And seem to have poor reading comprehension and understanding of basic AC fundamentals. I'll make it easy for you. here is an AC performance chart directly from Honda. you cant go wrong following these guidelines, hell it even tells how to test the Civic.

DCFIVER

Learn....And realize that system charge and airflow also affect highside pressure.

justinsbg

Are you seriously going to deny irrefutable evidence of what a proper working a/c system looks like? At the same time say I have poor reading comprehension? What a joke. There is a video of a perfectly working a/c system OUTSIDE on a 87 degree day and the pressures are just as I said they would be. What more do you need? You can post charts all day long, but charts don't fix cars. Experience and Knowledge together diagnose and repair cars, and it is more than clear you lack a little of both. I hardly believe your unmerited arrogance. Please, accept the facts as they are and admit that you're wrong. Quit taking stabs at me when all I've done is post cold hard FACTS. Also quit wasting time posting charts. It's almost pointless at this stage. I understand the charts and I use them approprietly. The only one who needs to step back and learn something is you sir. Have a good day.

DCFIVER

No you did not prove anything. You said "I expect to see 175-185psi on a 90 degree day." I told you that is incorrect and you will not see those pressures. You posted a video of a car on what you claim was an 85 degree day clearly showing your highside pressure at 190 psi. You only proved yourself wrong. As i have already stated numerous times as the ambient temp climbs so will your high side pressure. And you will not see 175-185 on a 90 degree day. On a 90 degree day you will see 200-220 psi. That is normal. You are too inexperienced and lack basic AC fundamental knowledge to realize this. Fine. Ignorance is bliss for some people. But i will correct your misinformation on this board. I have seen plenty of "experts" like you come and go, youre not the first stud. Take a class, gain some experience, then come back and try to spar with me on this, because as of now your talking gibberish....

justinsbg

Which is it man, 250,220,210,200 because according to you it could be any of those pressures at 95 degrees. I think the more you talk the more I can't bear to read your nonsense. PRESSURES WILL NOT FLUCTUATE AS MUCH AS 30-50 PSI BETWEEN 85-95 DEGREES, get that through your head. I might be fairly new to this forum, but I've already helped numerous people. That said, I'm not going anywhere my friend. I love repairing cars, and helping people. I'm excellent at both, and just because there's one sour apple in the bunch means nothing. I've dealt with people who "know-it-all" before, just like you. I've shown you what a properly working A/C system looks like, and I can't help you understand any further. You apparently don't understand or comprehend what's right in front of your face. I've asked you a question in a couple posts above that you haven't answered, because you can't. I stated that a good high side pressure will be between 175-185 +-5 and low side will be between 25-35 +-5 and it is exactly that. You can lead a horse to water but you can't make him drink.

djkurious

My readings 95 EX Manual
Temp outside was about 80

:

justinsbg

A side note and addition to all this a/c talk: If your vehicle is cooling to a comfortable level (usually between 36-42 degrees is the best you'll get) at pressures on high side of between 175-190 +-5 and low side pressures between 30-35 +-5 at ambient temperatures between 75-95 there is no need to put more refrigerant into the system. With pressures on the high side as high as 250 at idle, that's way too high. Any Honda/Acura I've ever seen cools just fine at an ambient temp of 90 and pressures as I stated. That's just the way it is. If your Honda/Acura doesn't cool well at those pressures and temperatures you have another problem you need to address. You don't want to stress the a/c system more than it already is by putting in too much refrigerant and raising the pressures more than they need to be raised. You'll create leaks and other issues pre-maturely. Sure I work an in a air conditioned building, but as soon as I refill a system I test drive it (in 90 degree heat) and it cools spectacularly. I'm happy, and more importanty the customer is happy (and they keep coming back). It's all because I diagnosed and repaired their car in a correct manner and put the correct amount of refrigerant into their system. Let me reiterate: if your car is not cooling well at the pressures I've given, you have other problems you need to address. Thanks for reading.

justinsbg

How is your a/c cooling at those pressures? What's the temp at the vents?

djkurious

I have a thermometer in my AC vents. In 90-100 degree weather, its between 38-40 degrees.
At night when its about 70-80, its about 32-35. I can see mist when its blowing at night. After reading this thread, I was thinking that it may need more freon...
When I first start the car, the cold air doesn't blow out until about 3 minutes.

justinsbg

On hot days it will take a while for the cabin to cool off to a comfortable level. That doesn't mean there's a problem it just means it's working it's butt off to absorb all the heat that's built up inside the cabin. If you're cooling at 38-40 degrees on a 100 degree day that's great. Nothing is wrong with your system, and I wouldn't do a thing to it. If you're blowing 32 degrees that means your evap core must be getting very cold.

poorman212

and just to keep this going.....ya'll are the tech's, I'm just stupid....at what RPM's are ya'll reading these pressures at.....I know what the manual says but there seems to be some debate about IF the manual is correct, so let's all get on the same page...oh, and then not forget about the OP's question......

justinsbg

These pressures we've been discussing are taken at idle, so between 700-850 rpm. Where is Youngsville near?

justinsbg

These pressure readings are taken at idle, so around 750-850. Where is Youngsville near in NC?

poorman212

Just wanted to be sure everyone was at the same rpm's......

PM sent on my location.

L2ILL

Hey I just want to thank you guys for the great info. Even the two guys that pulled out blades and billie jean'd each other with dull manifold gauge hooks.

Im going to aim for 185-90 hi and 30-35 low....on say 90ish day. I agree with Justin I think the most. I dont think the system will operate any better with higher pressures if it cant cool anymore.

I did finally find the low port...which pisses me off because I've charged on the high on this car..due to the low being so fuggin hidden and obscure (not like GM cars). The low is on the drivers side behind the driver side headlight.

I already replaced the compressor without damaging the radiator core. I pulled out the driverside fan to r&r. I placed new o rings on both tubes going into the compressor. I bought an o ring kit and plan to replace the same tube o ring up by the radiator where it meets its Hipress port. And if I can I will also take off the front cover to get the condensor cores low port connections. The compressor came fully charged and had oil on the low pressure side filled to the tilt which I did not take off becuase Im guessing they intended for it to fill or feed the drier then condensor.

The compressor also came with 2 different size dryers but the port arrangements look about the same....one is a direct drop in...the other could be managed in possibly. But I doubt the system uses 2 dryers...would anyone recommend i try to retro the larger one in? if its worth it? its slightly wider but about the same length. I think they just give you two so they cover both instances.

I will be evacuating the system before I charge...possibly for about 20 minutes...using an evacuator that couples to my 7hp compressor.

Does anyone know of any particular o ring seals I need to attack before I seal it all off again? any known bad bastards that always cause leaks.
I replaced the compressor not because it was bad....but I did need to annually throw in a can of freon...so there was a leak.....BUT the main reason is the clutch was definitely bad....and I did not want to wrestle with replacing the cluthc on it alone while on the car...so I decided to do the whole thing and replace them both. I now have a very cold blowing oem compressor with bad clutch and 122k on it.

I would like to thank you guys again. ALL.
Im expecting good results Ive done this job before 2 times.
1 is excellent-Chevy.
other is an 03 honda keeps leaking the freon out but blows cold when charged.
Whats a good leak detector? I have the green dye stuff in shed just havent put it in yet in that car because of this car being in driveway.

justinsbg

I would not charge on the high side anymore. It can cause compressor damage. I would gas up both sides initially before you crak the engine, but fill only the low side while the engine is running. I've never seen a compressor kit come with 2 driers so choosing which one is completely up to you. If it were me I would choose the one that was easiest to install. I don't think the size of the drier will provide a considerable difference. I like to evac for at least 30 minutes, sometimes an hour depending on how long the system has been open to atmosphere. A tip while evacuating: pull a vacuum for about 10 minutes then shut the evac off and close off your gauges and note where your gauge needles are. If the needles move from negative pressure within 5 or 10 minutes then you need to look for a leak.

DCFIVER

I lol'd
There is no goal to aim for. Your highside PSI will dependent on ambient temp ,charge ,airflow and compressor size. My only advice is, despite what you may have read from another member here, do not become alarmed if your highside pressure reaches 200+ range. There is nothing wrong with your system, as long as your vent temps are around 40 degrees or so and your low side pressure is between 30-40 psi. (Again these readings are very much dictaded by the ambient temperature.)

You should always pour out the oil and measure it yourself. do not leave it to parts jockeys to ensure your system is properly oiled. You also should find out what the total oil capacity is in your system and oil each component accordingly. Too much oil in the compressor can result in poor cooling and poor compressor performance, including hydrolock.
Just use the dryer that matches your old dryer, and add oil to it!
Evacuate until your gauges reach zero, then aprox. 10 mins longer so as to ensure all the refrigerant is removed and will prevent any damage to your vacuum pump. Then vacuum your system for a minimum of 30-40 mins.

DCFIVER

Ok heres a scenario.. If a car comes into your bay, and the highside is 220 psi, and the low side is 35 psi (at idle) and the outside temp is 95 degrees and vent temp is 40 degrees, what is wrong with this vehicle? How do you repair it???


*I am not trying to argue at this point, but rather trying to get into your line of thinking. If you believe there is a problem with the above mentioned vehicle , the you should have a logical approach to diagnosing the problem. With this information I may better hope to understand your experience and thoughts with AC systems.

justinsbg

Not to bounce around your question, but we just don't see high side pressures as high as you were mentioning unless someone has added refrigerant to their system trying to fix a problem that adding refrigerant won't fix. If a customer was in for some type of service and they were'nt complaining about a/c performance then I would not try to sell them something that they didn't feel was a problem. I've stated the pressures that I feel are best suited for the cars I work on which is Honda/Acura. They're pressures that I deal with everyday and know with 100% certainty they'll make the customer happy. If a sealed a/c sytem cools it's best at the pressures I've given then why would you raise it? Higher pressure=higher stress. Don't you think a system with 250 psi would create problems sooner than one with 190?

MyFreakGSR

You could just buy a real a/c machine to properly charge the a/c system (Robinair makes a good machine for $2500 (for those with a shop). A machine that accurately adds refrigerant by the amount (oz/kg) and not do it by pressures. Cars have come to the point where very little refrigerant is used in an a/c system than older cars so pressure can still read accurately and yet still not operate properly.

Alot of the honda/acura cars take .45-.55kg depending on model oppose to older cars having to hold .75-.85kg.

Temperature outside DOES affect a/c pressures, filling an a/c system based on pressure is an inaccurate way to fill them on todays cars. The high pressure for most honda/acura's are usually around 180psi, BUT if its 100+deg outside then a high pressure of 200-250 is not abnormal. I have seen it on numerous car (including honda/acura).

Just FYI: I work at Acura. I'm a Certified Acura Master Technician, A/C Certified, 4 ASE's (engine repair, brakes, manual drivetrian, HVAC), and have my associates in automotive.

justinsbg

Even in 100 degree heat I've never seen 250 high side pressure. We also do not refill systems based on pressure alone. We always add by weight, temp, and pressure. If that much pressure is on the high side at idle there is too much refrigerant in the system. Thanks for the input.

I too am a Honda master tech with an Associates Degree, numerous hours of aftermarket and factory training each year, as well as ASE certified in brakes, electrical, engine performance, and HVAC. I'm too lazy to go take any more. Maybe one day soon I'll be motivated enough to take the rest of them. Since we specialize in one auto brand they don't honor ASE certification.

L2ILL

Well I threw 2 cans in.....low side showed about 40 psi...it was like 95 today.
The low side is the bigger pipe right ? Well I had to fill on that pipe anyway because the other pipe had a much smaller fitting that I had nothing to couple to it with.
Anyway it has to be the low side becuase the manifold gauges reported the 40 psi. I am really tired and this entire operation with this car took way too long. mostly becuz I had been avoiding working in this blasted heat.
To top it off it seems the new compressor is also squeeking. Or maybe it's the damm alternator or power steering pump.....has me freagin wondering if I needed to replace the compressor or maybe not. I thought it was squeeking before becuz the clutch was bad...but the AC always worked ok...given it had a leak a can a year. So instead of replacing the clutch I just did the whole thing. while I did the water pump which was leaking and the timing belts.

But now the belt squeel is still present.

Steve Z

Hope you didn't screw it up charging on the high side?

L2ILL

It doesn't seem like that is the high port it's nowhere near giving high pressure readings.

So it turns outs this is the low side. It is the bigger pipe up front by the radiator on the pass. side not too far from the battery. So it is the most easily found AC port.


The OTHER port is a smaller pipe with a smaller nozzle that I had nothing to couple to it with...thankfully(because I thought that was the low side)....when in fact it seems like it could be the high side.

I've scoured the internet looking for a diagram that shows the low side more defined. but nothing.

If this is in fact the high side....it would need more freon as I am at about 40psi and it is blowing pretty freagin cold.

I even found another car that I pulled the little conversion ports to add to this car.....and it too showed the bigger port to be the blue(which is low) and the smaller port to go to the Red coupling (which is high).

Nothing new here with all the confusion....this fuggin car could never comparte to maintaining an american car. I am almost complete with this project and I will go back to never working on jap cars again....they are by far the most ridiculous and confusing set of layouts ever.

The smaller port/pipe is up front by the driver headlight it is almost fuggin hidden by design.....it usually takes me awhile to hunt it down....if this is in fact the low side it only adds to the ridiculousness of this car. It survives only by way of it's durability and reliability. And thank god for that and uncommon repairs needed.
So I can't take a high pressure reading from that smaller hidden port because my guage hoses dont screw onto it.

The car is also starting just fine(new timing belt+newWaterpump) which I thank god for becuz I think I would have junk'd it if it didn't....altho I do get some belt squeel which from some searching seems to be a common problem on these cars as the belts need to be tightened beyond what would seem logical.

Steve Z

Is it just squeeling when the compressors on? Could check tension and/or give it a shot of belt dressing. On my 95 LX they (the high and low pressure ports) are both right next to each other on the left side facing the the front of the car. And yes the bigger pipe is the low side.