r.etheridge

My a/c works for about 5 mins or so then starts blowing hot. I can turn it off for a second and turn it back on and it will start blowing cold but only for 5 mins or so then it goes back hot. Do i need to change out my Dryer and my TXV or is there something else im missing? I checked and the freon level is ok. The lines were broke apart about a year ago due to a hole in my condensier so I got a new on. They stayed open about 2 days but I did not change anything else at the time, dryer or TXV. And I didnt vacum out the lines when I put it all back together. Please help!!! GA is getting hot!!!! Thanks guys

Former User

This^ is a recipe for disaster. Go to the A/C section in the FAQs sticky to learn how to properly recharge the A/C system. Basically, you need to recover the refrigerant, replace the receiver/dryer, evacuate the system, check for leaks, and then recharge the system with the exact amount of refrigerant specified in the service manual.

r.etheridge

thats what i thought. I read the a/c part but didnt know if I also needed to replace the TXV as well as the reciever/dryer. The system doesnt have any leaks and it was only broken apart from the condensier nothing else. Also, what devices will I need to properly recover, vacuum, and recharge my system and can I get everything I need to check out from autozone rent a tool? thanks

Matt93eg

There is a lot of things wrong with what you did. Going about it that way will never give you desired results which is cold A/C.

Like Ron said, you need to have the Refrigerant recovered. There are people that want to do there own A/C work so they will take there car to a shop and have any remaining refrigerant recovered and then take the car home.

You can usually rent Vacuum pumps at Auto Parts stores as well as a Manifold gauge set. The lines were open for 2 days you said, The drier needed to be replaced as it was open to atmosphere. Also you said you didn't vacuum down the system. You will never get cold air without a deep vacuum.

r.etheridge

how much would a shop charge you to recover your refrigerant? I now have a good grasp on what I need to do this time around to get cold a/c

r.etheridge

so I take it I will need to replace the reciever/dryer before I vacuum out the lines then recharge the system correct?

Matt93eg

I have no clue, I have a friend that works at Honda so when I need Refrigerant recovered before I do A/C work I can take it him for that.

Correct, Just don't install it until everything else is buttoned up. You want to open up the Receiver/drier out of the box, pop the rubber plugs out of the holes only when your ready to install and then immediately pull a vacuum on the system. This way the Drier isn't exposed to open atmosphere to where it can absorb moisture.

For example, the last Civic I did A/C work on was my Mom's car. It leaked down and quit cooling and she called me up. I hooked my gauges up and the system had already leaked out all the refrigerant. I started to pull a vacuum on the system to see how big a leak I was dealing with. I could get down to around 25 InHg and as soon as I shut the pump off it would stabilize towards zero but not at a fast rate. I pulled all the lines out and replaced all the o-rings. Pulled another vacuum on it..still with the old drier in place. Got it down to just over 28 InHg, let it sit for an hour and it was still holding. I was then ready to install the new drier because I knew I was leak free. Put in new drier. Pulled vacuum again to just over 28 InHg. Let it sit for 30mins and the system was still holding. I then charged the system with Refrigerant.

r.etheridge

so 28InHg is the magic number that Im looking to get and it needs to hold a negitive vacuum for atleast an hour to have a leak free system. Then change the drier and pull the vac again and if it holds steady for 30mins im ready to charge. got it. Thanks for the help. Im pretty sure the system is leak free because it has held refrigerant in it for about 5 months now but I didnt vacuum the lines nor did I change the drier so I think thats my main problems. I will still check to make sure the system will hold a vac for an hour or so. Thanks again

r.etheridge

now will the vacuum pump tell me how much im pulling as far as InHg or will I need a manifold gauge set?

Matt93eg

I don't know that 28InHg is the "Magic Number", I have always been able to get a Vacuum using my Vacuum pump to atleast 28InHg if not a bit better. Just think of 29.92InHg as perfect Vacuum..so your trying to get as close to that as you can. For example, your A/C will never blow cold at say 15 to 16InHg. And that Holding a vacuum for an hour is just my process. I have my way of doing things. Also apparently not all Vacuum pumps can pull as deep a vacuum but I don't have any experience except for the one I have.

You will need a Gauge Manifold set. Make sure the O-Rings on the quick disconnects for the High and Low side ports are good and not leaking. I have had these leak before when I was pulling a vacuum making me search for a leak before I realized it was one of those O-Rings leaking.

r.etheridge

I took it to my buddy because I didnt have the equipment to do everything I needed to do. He pulled a vacuum of atleast 26 InHg (his recovery/refill machine doesnt give a direct reading just if it drops below 26 it will let you know what it is) and it held for an hour. He put 1.1 lbs of freon in and it cools like a ice cube. Thanks everyone for the info!

Former User

You added just under 18 oz of R134a but I believe a proper system recharge takes 21-23 oz.

r.etheridge

he looked it up on his computer and said it took 1.1lbs. thats what he put in and its blowing pretty cold

Matt93eg

This is what I believed as well.

OP, how hot is it right now where you live? If its 80 to 85 degrees then that amount of Refrigerant may be ok..but you will find out once it gets hotter and humidity levels kick up. There's a big heat load difference on the A/C system on a 95 to 100 degree day versus an 80 to 85 degree day.

On a 94-95 R134a Civic..I usually put in 22 ounces because that is between the 21-23oz scale like Ron mentioned above.

r.etheridge

its already 90 here but if it stops cooling, I can get more added, the guy that owns the place is a good friend of mine but I wonder where he got that it takes only 1.1lbs at?

Former User

Also, some oil is removed during recovery of refrigerant from the system. Did your buddy note this amount of lost oil and then add the same amount of new oil during the refrigerant recharge?

r.etheridge

he did add oil but not sure as to how much