So I finally have a little money to throw at this problem. Last year was HOT and I don't want to repeat that experience.

I have owned my 95 accord EX coupe about a year and AC has never worked. I bought the gauges today and I am getting about negative 10 psi on the low side (BLUE) and about 60-70 psi on the High side (red) while running. Compressor comes on and runs and air blows hot. Ambient temp today is about 80 degrees.

Please Help.

 

Plugged expansion valve is likely.

 

You are just low on refrigerant. Add some until low side is 35psi or so.

 

Normally if you're out of freon you probably have a leak. It would be best to add leak detector. If after adding freon it gets cold but stops shortly after, you have a clogged expansion valve. It would be best to replace the receiver/dryer before you fill the system.

 

I went ahead and spent $80 at rockauto.com for a new expansion valve, evaporator core, dryer/accumulator and a new o-ring set. I kept seeing expansion valve as a possible cause and it appears I have to pull out the evap core to get to it so I might as well replace it if a replacement is only $30.

So before I start the car I have pressure on high and low side of about 35psi. Car has not had hot air for almost a year and a half. I would think if there was a leak a year and a half would be enough time to get the pressure out of the system. And most of what I have read is that negative pressure on the low side is a strong indication of a blockage in the system.

I was really scared about tackling this but as i have done some research it seems I might be able to pull this off. My biggest fear is taking it to the mechanic to get fixed where I know I will get ripped. last time i took a car in for AC service they quoted me $800 and while they diagnosed it they had to replace a fuse to get the compressor working. The fuse solved the problem but they still felt the need to call me and let me know it would be $800 to get it working before I picked it up. ASSes

 

keep in mind that even though there is no freon left there is going to be pressure so be very prepared when you go to open the system.

 

Our cars do not use "Freon ". Freon is no longer being produced. 1993 and older use R12 Freon , no longer available. You will have to convert the car to use R134. See an AC shop to determine what needs to be replaced and cost. They use refrigerant r134a. They stopped making Freon in 1994.

 

actually he never called it that, I did. I just call it that still but I'll make sure I call it refrigerant in the future to avoid the confusion. My car was already converted to 134

 

UPDATE!

Ok.... $300 later this is what I got. I changed out the expansion valve only. The evaporator core i ordered was the wrong part. #@*%!!! So whatever. I got the remaining pressure out of the system and replaced the part and put it all back together. I then used my brand new suction pump thing (I forget what it is called) to put negative pressure on the system and get all the moisture out. After about 30 minutes of that I emptied one 12 oz bottle of R134a into the low side port. It sucked it right up. At that point it would cycle on and off with the low side pressure reading 30psi up to 70 psi and then back down again. I did not have the highside pressure connected at this point so not sure what it was reading. I then emptied the second bottle into the system and I tried to not let it all go in but I screwed up and most of it got in there. So I'm thinking I put in maybe 23.5 oz of refrigerant and the sticker on the car says it needs between 22 -23 roughly. Anyway after the second bottle was in it was not cycling anymore and the pressures remained static. low stayed around 30 and high was around 120psi.

So.... I don't really have a thermometer so I can't really say it is working. Felt cold to me but its only 70 where I am today. Regardless of that I was under the assumption that the compressor would be cycling on and off and currently it just stays on. Should I bleed some refrigerant until it starts cycling or is this normal and I should leave well enough alone.

I also stuck dye in the system to see if there are any leaks. Hopefully there will not be any. But tomorrow is a new day and I need suggestions. Gonna be real hot this coming week and I am hoping I can get this solved tomorrow.

 

Bump

 

Yes, it should cycle on and off. You should replace the receiver/dryer .

 

From what I have read around other forums is if the compressor does not cycle off it may be that cabin temp has not reached desired temp setting. I'm thinking I'll drive it around this coming week and see what happens. It has not exploded. Pressures are on the low side but within normal ranges and I checked for leaks with a UV pen light in the dark last night and I can't visibly see anything indicative of a leak. I plan to replace the accumulator/dryer but I don't feel like buying an extra one so i plan to wait until the system performs correctly for a week or two before I replace it.

All suggestions are still appreciated.

 

UPDATE:

So it's a little hotter today. About 70-75. I go out this morn and start it up and its obviously colder when the AC button is on than when it is off. I read in another thread to check the hot/cold blend door cable. So I get upside down and look at the blend door and I turn the **** to cold and then with my hand I grabbed the blend door handle and turned it about two more clicks towards cold. At that point the air got colder. Right about then I heard the compressor kick off. For the next 10 minutes it was cycling on and off like normal. Only down side turning blend door manually is now I can't turn it back from the ****. I guess that is a much simpler issue and I'll read elsewhere to figure out how to adjust it.

However the air is still not icy cold but it is an improvement. Only thing I can think of is to replace the dryer/ accumulator to increase flow of refrigerant. If it is a filter it is more than likely clogged somewhat? Also the Low side line coming back from evaporator is icy cold. And the high side line headed to evaporator is about ambient temp. Is this right?

Also after sitting overnight I'm going to assume I don't have a major leak cause the pressure readings were actually a tad higher today than yesterday. Now I failed to mention that after vaccuming the system I could not get it to hold the vaccum. If it's leaking I think it was on the gauge lines but I'm not sure. This is a real pain in the ***. At this point I plan to drive it around a couple days and see if I can force out some of the coolant with the dye to track down a leak if there is one.

 

The blend door adjustment is pretty easy....there are two cables and the heater valve involved....PS check the **** of the dial on the dash just to be sure the shaft is not broken.

 

Yes the receiver/dryer can block the flow of the refrigerant.

 

Update: So I ran the car for about a week with the AC on. I checked pressures and they had dropped. So I have a leak. I managed to generate only one area where I could see my refrigerant was leaking from the dye I added. it was the low side line connection i took loose to get the evaporator out near the firewall. So I pulled the evaporator and examined it in the dark with my black light and I could not see any signs of a leak. I reinstalled the evaporator put a new o-ring on both connections and tightened them up. i also replaced the valve cores just for good measure.

So now I am thinking I will put the vacuum on the system and see if it holds. Well one problem there. I can not get a good seal with my cheap *** harbor freight gauges. I hooked everything up but i did not screw the ***** down that would open the Schrader valves in the hi and low pipes and it will not hold a vacuum. I tried some o-rings from the o-ring kit I had. I tried it tight, loose, all kinds of ways and i could not keep a vacuum on the lines.

Anyone know how to get these things to seal up correctly. I'm kind of pissed I forked out $50 bucks and they won't seal. Thinkin i will prob just fill it up with freon again and see if it doe not lose pressure.

 

I have used those and they do work. It's hard to figure out at first. I have taken mine back already lol ...just paid the restocking fee...but it's not how you would think they work but they definitely do work. It's just kinda hard to figure out at first. Take another look, if you can't figure it out lemme know.

 

You are just low on refrigerant.

 

So I fiddled with the hoses and managed to secure a solid vacuum in the lines once I closed off the service line. Ok... this is good. So I think just to make sure no air seeps into the system from the gauge lines I take the hi and low quick connects loose from the Hi and Low aluminum lines and darn it if the hi side line doesn't start hissing where it is drawing air in.

So WTF! Is this a problem. They are brand new valve cores. I am not really sure how they are supposed to be installed. I screwed them in till they started to snug up a little and I stopped. The tool would not really go in much further anyway.

Can a valve core hold negative pressure or is this forcing air in a direction they were not designed to hold?

Please help. Not sure if I boogered the new valve core on install or if this is acceptable.

Feeling really defeated with this project. Takes a damn day everytime i get stuck. And it's getting hotter!

 

You need to unscrew the valves all the way to close the system and you turn the ***** in to open the system. Is that what you're doing ? It's the opposite you would think.

You only use the bottom three components. The top two that face horizontally is only for putting the couplers onto for storage purposes.

 

I understand which direction to turn the *****. My question is why is a brand new valve core leaking out the negative pressure when I disconnect the hoses of my gauge.

I ran the vaccuum 30 mins. Then I closed off the ***** near the gauge dials for hi and low. I then unscrewed the ***** at the service ports and then disconnected the hoses from the service ports. At that point one of my new valve cores was leaking to the point where it was letting in air because I had a vacuum on the system.

How hard can it be to install these valve cores. How tight do you screw them in. They seemed pretty fragile so i turned them in until it got a little snug. Should I tighten them more or do you think i got a faulty valve. One is leaking while the other is not so i guess I put one in correctly.

 

Obviously if it's leaking at the inner valve it must be faulty or just made cheaply. If it's leaking on the outer, then ya tighten it down more.

 

UPDATE:
Picked up a new set of valve cores and went to replace the one that was leaking and it was stuck! It would unscrew to a point but the plunger was hooked on something in the port. I think I have to be the first person to get a valve core stuck. Anyway, I grabbed it with some really small needle nose pliers and pulled it out. I managed to bend the little metal disc on the bottom of the valve core that holds the rubber piece. Anyway reinstalled new valve core and had to turn it in as far as my tool would go but it finally got tight and sealed. THANK GOD. Ran a vacuum yesterday and closed off the Gauge valves and then closed off the port valves but left them attached. I went out today and the hoses had not lost any neg pressure. I screwed in the ***** for the port valves and the neg pressure did not drop at all so I think it is safe to assume neither the hoses or my AC lines lost any neg pressure overnight.

So I am feeling confident I have fixed my leak and I will replace the drier next chance I get and then re test for leaks. I wanted to make sure I confirmed no leaks before drier install so if I get leaks after drier install I will know it is at the drier connections.

Fingers crossed.