JJT211

I changed the compressor and receiver dryer, evacuated system to a perfect 29 inhg and as im charging the system the pressure goes up as i charge but when i close the valve to check pressure. My gauge goes back to reading 25-ish inhg. Im already halfway thru my secind can and im afraid to go any further in fear of over charging.

My compressor clutch did kick on within seconds of charging and i did let the vacuum sit forto check for leaks.

So when im charging i should be seeing some pressure b/w 35-30 psi (according to the pressure temp chart) current ambient is 75 and humidity 80%

My ac is currently kn and only blowing about 5 degrees colder than ambient

Ive gotta be missjng something any help greatly appreciated!

JDMLyfe89

this is the way i was told to do it

start the car turn on the ac
take the r134a and connect it to the high pressure nipple i believe idr off hand the connector only fits one
rev the car at like 2500 rpms let the can drain
and do it over until it blows cold the needle on the gauge will go into the red a few times the system shouldnt take more then 3 from what i know since you started fresh with no freon in the system

JJT211

You're right, the connector only fits one, and it's the LOW side. Charging high side would be very very bad! Like blow up can in your hand bad. But you're correct....the one it fits on.

JJT211

Let it be noted this is my first run at auto AC

Lemme first describe the initial problem before I go any further. I bought this car with the AC completely inop. There's no telling how long its been without any AC. Guy I bought it from said that he doesnt know much about electronics, and the compressor isnt getting any power to engage the clutch but that his buddy tested the pressures and everything looks good. So I hooked up the manifold gauges to confirm that the resting pressures were according to specs. I then whipped out the circuit diagram and factory service manual and went to town. I was able to isolate the power issue to the wiring on the compressor itself. So I went on a hunt for a compressor.

There's the backstory to the OP

Now I didnt add any oil to the system because I was told by dude at Carquest that the can of r134 already had the oil in it (I should know better than to take dude's word at Autozone/Carquest/ect before I assume anything). But after reading the fine print more past the reg instructions, it says 'oil in this can is not a substitute for OEM oil'.





So after some further reading I decided I was gonna start over completely from scratch by taking the compressor back out and completely emptied the oil, fill with new oil, pull vacuum, add 10mL of oil to the system for the receiver drier and recharge again with r134 AND UV dye. After that point, with everything to spec, I can hopefully rule out the compressor and recevier dryer. Inspect for leaks if necessary and might have to move on to other parts of the system that may be a prob.

As I was about to add the refrigerant oil I saw I had accidentally grabbed PAG 100 as opposed to PAG 46.





It's 11pm here and everything is closed. So Im packed it up and will tackle it tomm....

So do you think I could've jacked something up with a lack of oil? The junkyard one appeared to have the correct amount of oil I emptied out of the relief valve port. Which leads me to ths question, I've read it doesnt matter where you add the oil, directly to the compressor or while you're recharging the entire system. But it appears that the compressor has its own oil as well, hence the relief valve port.

I dunno....any help greatly appreciated!

strategy400

Get a cheap digital scale from harbor freight and weigh in the exact amount of refrigerant (you can watch the grams leave the can as you charge). Someone might be able to help you with that info but it seems you've left out important details like the car info, part numbers etc. For my car/system it was 500-550 grams but I have an accord that takes 600-650 some of the later model civics also take 600-650.
In my experience, there isn't more than a few drops of oil in the compressor (less than an oz.) so damage to the system was probably not done by lack of oil. The entire system usually contains approx. ~4 oz. of oil.
My compressor locked up and I replaced drier, compressor and condenser, weighed in the proper amount of refrigerant (ended up being 530 grams or about 1 2/3 cans). People always complain that their ears are cold in the car.
If your system became contaminated somehow then you might have to replace the expansion valve, which is basically a nozzle that sprays the compressed liquid refrigerant into your evaporator (where guess what it evaporates into a gas and makes things really cold). It might be clogged. I would try a proper charge first because its a lot of work to change it.
If you open the system again consider changing your condenser, I got mine at radiatorbarn.com for a good price and they always deliver quickly. My A/C gets uncomfortably cold sometimes reading 39 degrees F at the vents and its been running fine for 2 years. I live in the desert where temps hit 110 routinely in summer.
Charging by pressure isn't an exact science you have to allow for different ambient temperatures, its better to weigh it in. I will say for my system I charged the exact amount of refrigerant in and my static pressure (everything off/not running) was ~65 high and low sides equal @ ~60 degrees F ambient air temp.

JJT211

^^^

Great feedback. Thanks helped alot!

It's a 98 Civic Cx btw...Today was 70 degrees with 50% humidity. Beautiful day!

Well today I got the proper oil and did a full AC charge and im still having the same problem.

My compressor now engages and I get a healthy pressure on the LOW side but the HIGH side is a very low. It stays stuck at 100 psi. As the AC continues to run, HIGH side continues to run abnormally low at the same pressure of 100 psi but over time the LOW starts to creep up high.

Im thinking that the LOW side is fine and there's something wrong with my HIGH side, and the reason why my LOW side starts to build over time is because the HIGH side is not doing its job.

All the above readings are when the AC is turned off. But when its the low side still appears to be under a vacuum.

The pressure chart below is pointing to the expansion valve. Ill give that a whirl and report back.



So the expansion valve is a PITA eh? Guess ill find out!

strategy400

Again I wouldn't dismiss the condenser as a suspect. Its in there that the compressed gas cools and becomes liquid again. Maybe its not performing adequately to create the liquid form necessary to build pressure before the expansion valve and resultant expansion of this liquid to gas as it passes through the valve, resulting in the pressure readings and lack of cooling you are experiencing.
This is all pure speculation on my part.
Were it me I'd spend the ~$70 and replace the condenser. It can't hurt and its easier than that bleepin' expansion valve. The only bitch is the metal pipes between it and the receiver. And be careful with those fittings because they are one step above tin foil. Use two wrenches. They don't require 1000 ft. lbs. (the o-rings will do their jobs).

JJT211

LOL...Everything's suspect until I have some proper AC.

And you're correct the Evaportator and Expansion Valve is a biaaatch to get to. But Im glad I went down there though cuz now I see where that Cabin Air Filters is supposed to go. Man my Evaporator was just downright disgusting. I tried to find the Cabin Air Filter and its frame late last night to no avail. So i put the project on hold til tomm or later this week. Tomm, Ill be scouring the junk yards for 97-01 CRV's and 00-06 Odyssey's. If that doesnt work out ill go to the damnn dealer

I got my evaporator drying off from its much needed bath. Ill try to get into this tomm before work.

The worst part about bringing an AC system back from the dead, is how much money you waste on charging the system to further troubleshoot. My cans are like $40 a pop.

This damm AC system will NOT kick my *** any longer! Ill make Frosty my bitch!

JJT211

I always hate when i do a search and I find a thread with MY problem but the OP never replies back with the fix.

So here we go.....I went to my local junkyard to hunt for a cabin air filter housing and found a fresh 99 civic that had the cabin air filter ready housing and evap. The junkyard evaporator was actually in better condition than the one that came out of my car, so used that one and popped on the new expansion valve, installed the evaporator and housing (this was a BIATCH to get out but not bad at all to get back with the new evaporator housing. I made sure to install rear clips BEFORE i put in the housing and it slipped it nice and easy) and a brand spanking new cabin air filter and BAMM, my AC is blowing icicles!