A/C high pressure service port

rkvons · #1 06-19-2010, 07:11 PM

So I have this 1998 Trans Sport Montana, and I changed my A/C compressor today because I think it was leaking. I put a set of gauges and a vacuum pump on it and pulled it down and then I proceeded to put three cans of freon in it. It has the rear A/C in it also. I took it for a test drive to pick the wife up from work and I determined that it needed one more can. So when I got it home and took the cap off the high pressure surface port, it was hissing at me. I struggled with it for a while and could not get it to stop leaking. I eventually put a piece of rubber in it and drove a bolt down on top of it. My question is: is the service port/valve repairable or replaceable and how do you get it off to repair or replace it? If it is replaceable, what part(s) do I need. Thanks.

dewaynep · #2 06-22-2010, 02:15 PM

There is a kit that has replacement service ports in it. It is made by Dorman and is part # 800-600. The kit is expensive so your best bet is to see if any A/C shops in your area have the ability to do this for you. The other option is to change the line. If you do a search for replacement service port you may find one that you don't need the special crimping tool for. They may have some that are compression fittings and use simple tools to install.

doctorhrdware · #3 06-22-2010, 07:55 PM

All the service port has a valve core in it. Just go to an HVAC supply house and get the valve core from there. It is different from the valves used for your tires.

dewaynep · #4 06-23-2010, 02:39 PM

I believe the high side port is a different valve than a schrader valve. You are correct on the low side though.

doctorhrdware · #5 06-23-2010, 11:01 PM

Quote:

Originally Posted by dewaynep

I believe the high side port is a different valve than a schrader valve. You are correct on the low side though.

Well I was at the local AZ returning some core items. They have a valve replacement kit for both the high side and low side for $4.99. What the kit includes is two schrader valves for the low side and the high side and 2 new caps for the low and the high side for the AC system..

rkvons · #6 06-24-2010, 09:14 PM

Well I located one at a local auto parts store. I've included pictures of it. I have not put it on yet, because the system is cooling right now, but if it ever leaks, I will put this on. It does not appear to be serviceable besides entire removal.
hi_port_1.jpg

hi_port_1001.jpg

kcarlen · #7 07-07-2010, 07:52 PM

Rvons,

You mentioned that you had the HIGH PRESSURE valve hissing? Is this the one on the Drivers side? I have had a leak for quite sometime now, and I have always heard something in this vicinity. I pulled the cap off, and could not feel anything,
I even pulled my airbox, and computer out of the way, to look for another source of the hissing sound. Under the airbox is the T that goes to the rear. I have heard that the rear lines cause issues....so this is what I determined was the issue, Until I read your post about the high side.

So far, I have not been able to locate the leak, but all I can say is that a full charge does not last longer than 2 days, if I am lucky.

I borrowed an ultraviolet lamp from a friend, in hopes of putting in some more Duracool and trying to find the leak. I don't have the special glasses though....so I am waiting on locating those....

Did the replacement valve fix the issue?
I see from the post above that you are waiting for the leak to come back...

kcarlen · #8 07-07-2010, 08:25 PM

Is this considered the High Side?
I hear constant hissing around this area.

rkvons · #9 07-08-2010, 10:28 AM

Quote:

Originally Posted by kcarlen

Rvons,

You mentioned that you had the HIGH PRESSURE valve hissing? Is this the one on the Drivers side? I have had a leak for quite sometime now, and I have always heard something in this vicinity. I pulled the cap off, and could not feel anything,
I even pulled my airbox, and computer out of the way, to look for another source of the hissing sound. Under the airbox is the T that goes to the rear. I have heard that the rear lines cause issues....so this is what I determined was the issue, Until I read your post about the high side.

So far, I have not been able to locate the leak, but all I can say is that a full charge does not last longer than 2 days, if I am lucky.

I borrowed an ultraviolet lamp from a friend, in hopes of putting in some more Duracool and trying to find the leak. I don't have the special glasses though....so I am waiting on locating those....

Did the replacement valve fix the issue?
I see from the post above that you are waiting for the leak to come back...

Yes, it is the one on the drivers side. The picture you have is the one that was hissing. On the day I discovered it leaking, the sun was shining in such a way as to cross over the top of the high-side service port. With this happening, I could actually see the Freon coming out as well as hear it hissing. I have not replaced the service port (valve) yet, because my system does not seem to be leaking anymore. I have jammed a piece of rubber down in the leaking service port and ran a bolt down into it to keep it from leaking.

As the compressed Freon goes from the high-pressure side of the system to the low-pressure side (through the expansion valve) it will hiss. This is also on the driver's side and is probably what you are hearing. I have the same sound now even after my system does not seem to be leaking. Let me ask you. How is your compressor? Does is look wet? Was there ever any leaks of oil coming off of it that seemed like it was not motor oil? These compressors leak when they get old. Also, if yours leaks out in a couple of days, it seems like you would almost be able to smell it. Are there any wet spots on your condensor? This would surely be a leak.

kcarlen · #10 07-08-2010, 04:28 PM

With regard to being able to smell the leaking gas;
The can of Duracool mentions that there is a scent added, and I can smell it when I am filling the system, but I have NEVER been able to smell the thing under the hood other than at that time.

The compressor looks ok, never any sign of oil on the ground. It cycles when told to with the correct PSI,

I am glad that the hissing is normal....

I just wish I could find this leak.
I bought 5 cans of the Duracool last week when it was on sale for $10/each.
I don't want to waste it, but I will maybe locate some glasses, and put in one can and see if I can see anything unusual.

What is really weird is that even when the system was running at about 50PSI with the compressor cycling, it did not seem to get cooler in the cabin.

It seems like I have 2 problems......One massive leak and something else!
The darn thing used to be good....
Thanks for your guidance, it appears like you know much more about this than I.

tinman22 · #11 07-11-2010, 08:45 PM

I have a Malibu Classic. The AC high pressure service port is leaking. It looks like a check "ball" in the bottom of the valve and not a schrader valve. When i pushed on the ball with a screw drive i don't see the steel ball anymore but a piece of rubber and the leak got worst. I put the plastic cap back on and it appears it stop the leak for the time being. Is this some type of check ball valve or is the schrader valve behind it. Do i need to uncharge the system to replace?

tinman22 · #12 07-11-2010, 09:12 PM

I have a Malibu Classic. The AC high pressure service port is leaking. It looks like a check "ball" in the bottom of the valve and not a schrader valve. When i pushed on the ball with a screw drive i don't see the steel ball anymore but a piece of rubber and the leak got worst. I put the plastic cap back on and it appears it stop the leak for the time being. Is this some type of check ball valve or is the schrader valve behind it. Do i need to uncharge the system to replace?

rkvons · #13 07-13-2010, 12:44 PM

Quote:

Originally Posted by tinman22

I have a Malibu Classic. The AC high pressure service port is leaking. It looks like a check "ball" in the bottom of the valve and not a schrader valve. When i pushed on the ball with a screw drive i don't see the steel ball anymore but a piece of rubber and the leak got worst. I put the plastic cap back on and it appears it stop the leak for the time being. Is this some type of check ball valve or is the schrader valve behind it. Do i need to uncharge the system to replace?

A couple of things. If it was leaking initially, it needs to be replaced. The plastic cap will not stop it from leaking no matter what you've heard. You just can't hear it anymore. Also, is it the newer system using R134A? Does the high-pressure service port look like the picture in the thread? If so, you should be able to replace it. You take the whole tip off. You will have to evacuate the system to do it. Don't try taking it off when it is under pressure or you may put a neighbor's window out.

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