A/C service port durability

JMR

Member
Joined
Jul 23, 2014
Location
Strathmore
TDI
99.5 Jetta
Has anyone ever had any issues with the durability of the A/C service ports?

My compressor was failing on me, so I bought everything I needed to re-do my whole A/C system. New compressor, new dryer, new TXV. Got all of that installed with new orings as well. Bought a manifold gauge set and vacuum pump to do it all properly.

My issue is I was getting unreliable gauge readings while vacuuming the system, and charging as well. Turns out my low side service port was having problems and most of the time wouldn't open up properly. So I replaced that with a new one and all was good. Managed to vacuum the system down properly and charge it up to 35 low side and 190 high side using the equivalency charts that Red Tek provides for their 12a.

A/C worked great today, but I wanted to check the pressure and make sure everything was good with no leaks. Clipped on my gauge set with the quick couplers and again was getting no reading on the low side and a reading of about 50 on the high side. A/C was still operating and blowing cold, so I figured that couldn't be correct. Wiggled the low side connector and got a bit of a reading on it. Figured I would leave it alone as it was still working great and I had the pressures perfect the night before. Pulled off my quick coupler on the high side and the little rubber piece in there blew completely out of the port and sprayed all of my oil and refrigerant all over the car and into the air, ruining all of my hard work. Pretty disappointing to say the least.

I suspect that I may have a set of crappy couplers on the gauges that appear to keep ruining the rubber seals in my service ports, so I ordered new couplers. Just wondering if anybody else has had any trouble with the service
port seals going bad on these cars? Or if it's as I suspected and the gauges came with junk quick connects that are punching the rubber out.

It seems like sometimes they open properly and sometimes they don't. Its been driving me crazy. Any insight would be awesome.
 

Bran Diezel

Veteran Member
Joined
Jul 13, 2009
Location
Bristol, Va
TDI
On my 5th TDi - 2003 ALH 5spd Wagon
Having an ac machine and doing many cars a year I find that my fittings on my machine wear out about once a year. I guess they are crap. One thing that has helped me prolong them is to put some ac oil on the high and low ports on the car before hooking up the gauges which keeps the o-ring from stretching or getting nicked in the process. Maybe that will help you a little?
 

JMR

Member
Joined
Jul 23, 2014
Location
Strathmore
TDI
99.5 Jetta
Having an ac machine and doing many cars a year I find that my fittings on my machine wear out about once a year. I guess they are crap. One thing that has helped me prolong them is to put some ac oil on the high and low ports on the car before hooking up the gauges which keeps the o-ring from stretching or getting nicked in the process. Maybe that will help you a little?
Thanks Bran, I will try this next when I work on the car next. I think that is part of the issue. Old, dried out rubber valves in the service ports probably cracked when the couplers pushed on them.

Just discovered yesterday that the high pressure service port is welded into the high pressure line and is not removable. Because the rubber seal is completely ruined on mine, I have to replace the entire line between the receiver/dryer and expansion valve. That's going to be some work... VW wants over $300 for a new line. Junk yard here I come!
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
You sure the port doesn't unscrew? I think it was the high port that I replaced on my '2.

When you disconnect are you closing the valve on the coupler first?
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I've found when I screw the knobs on the couplers in all the way they collapse the springs on the schraeder valves in there. Then all the juice comes out violently when I disconnect the lines.
Solution to that particular one is to not bother trying to "backseal" the knobs, just turn them until the gauge needles come up.
 

JMR

Member
Joined
Jul 23, 2014
Location
Strathmore
TDI
99.5 Jetta
Are you using cheap harbor freight tools? Are you using oem ac lines?
Using FJC air conditioning products, so mid grade tools as far as I know. The couplers I replaced with Rainer american made ones that work much better.
You sure the port doesn't unscrew? I think it was the high port that I replaced on my '2.
When you disconnect are you closing the valve on the coupler first?
Yep, definitely does not unscrew on my 99.5. The low side port does and I changed that out, but the high side sure didn't. I went to a junk yard and pulled a high side line off a VR6 and it was the same way.
Original couplers that came with the kit didn't have a valve on them. Only quick disconnect that opened the service port at the same time. Replaced those with better quality ones with the knob for opening and closing.
I've found when I screw the knobs on the couplers in all the way they collapse the springs on the schraeder valves in there. Then all the juice comes out violently when I disconnect the lines.
Solution to that particular one is to not bother trying to "backseal" the knobs, just turn them until the gauge needles come up.
486 hit the nail on the head. With the other couplers I was using, they put too much pressure on the rubber seal and spring in the valve. They were crushing the spring down when you pushed the coupler on, and the service port would no longer seal after taking it off. Expensive lesson to learn there... I bought higher quality manual couplers and screw them down until they just push the valve open, instead of crushing it down hard. Seemed to work much better.

Changing the high pressure line between the TXV and drier is no fun. Everything has to come out. Coolant reservoir, fuel filter, washer reservoir, intercooler. If anyone is thinking of servicing their A/C system I would highly advise getting couplers with a manually controlled valve on them. Otherwise you run the risk of wrecking your service ports.
 

JMR

Member
Joined
Jul 23, 2014
Location
Strathmore
TDI
99.5 Jetta
I replaced both on my 02. Believe me, it comes off.
Sure didn't on mine, and I was cursing them for it. I pulled the line off and it is 100% welded directly into it. Not a chance of replacing it. Went to a junk yard and just for the hell of it, tried on another Jetta. Put a socket over it and cranked on it. Folded the line in half because it was welded on. Went to a second car and removed the line so I could replace mine. This one was also welded on.

Sounds to me like later in the years they got wise and decided to have a replaceable port like they did on the low side.

Either way, it is now replaced and the leak sealed. Just something to keep in mind for others that your high side service port may not be as easily replaceable as the low side.
 

TDI_FNG

Well-known member
Joined
Jan 28, 2013
Location
Kirkland, WA
TDI
2004 Jetta
Not to revive an old thread, but perhaps it might save some else the trouble I went through.

I had the exact same thing happen as JMR, high side blew like Old Faithful. Went to replace service port and put the socket on what looked like the service port. Ripped the line right off.

Being resourceful (or lazy, you decide) I purchased a generic high side port from NAPA, attempted to cut some threads into the line and attach the new service port. Of course I couldn't get it to seal, so out comes my trusty tubes of JB weld. It would hold for about a month, then need to be recharged.

My local auto parts store had a kit with both low and high side ports for under $20. After taking a closer look at the high side and comparing it to the piece I tore off (I don't really know why I saved it, but I'm glad I did), I could see that what I thought was the high side port was really just made so that I didn't twist the line while removing the actual port. D'oh! It is a similar set up on the low side port, but since it is right up front and easily assessable, it is much easier to see.

Just for fun, I hit the local junkyard, because $250 for a new a/c line was too much, and to see what needed to be removed to replace it. It was much easier at the yard, with having much of the stuff removed already. Bottom line, it took me about 3 hours to replace the line and drier. And yes, I was able to replace the high side port on the line I got from the yard.
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
Sure didn't on mine, and I was cursing them for it. I pulled the line off and it is 100% welded directly into it. Not a chance of replacing it. Went to a junk yard and just for the hell of it, tried on another Jetta. Put a socket over it and cranked on it. Folded the line in half because it was welded on. Went to a second car and removed the line so I could replace mine. This one was also welded on.

Sounds to me like later in the years they got wise and decided to have a replaceable port like they did on the low side.

Either way, it is now replaced and the leak sealed. Just something to keep in mind for others that your high side service port may not be as easily replaceable as the low side.
Perhaps you had the issue that TDI_FNG posted about? I have NEVER seen one that was not threaded on, but everyone that I have looked at LOOKS as if it was not threaded on.
 

johnh2o

Member
Joined
Jan 30, 2008
Location
cedar park, texas
TDI
2003 jetta wagen-killed by distracted driver replace by 2013 Jetta wagon TDI
Hige Side Port Issues

i cannot get a reading off the high side port, expensive or cheap guages. started poking at it and now it is stuck open.....so now i am replacing it but no one sells just the valve and from the previous posts it looks like i get the whole line though i swear it looks like it is threaded on
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
I remember reading one of DanG144's posts saying it's sometimes necessary to have different reach length for those gauges.
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
You cannot just replace the schrader valve stem on the VW, you replace the entire housing, which threads onto the line. The bottom most hex is usually part of the stationary line. Do not twist the line off...

http://parts.vw.com/a/Volkswagen_20...193/CONDENSER--COMPRESSOR--LINES/9277140.html look at part # 14 and 16. This is what you take off and put on. There is a picture on the right of the price for part #14. Pricey.

Just going on what others have reported here, about not being able to simply replace the valve core...I have never had to do it.
 

02Andy

Member
Joined
Jul 25, 2015
Location
CA
TDI
'02 Golf
In case anyone else needs to replace their low pressure service port/valve, I found what appears to be an exact replacement at O'Reilly. It's part number MRY 26781. There's a high side valve included, and a couple valve cores, along with a couple caps. Their system doesn't recognize this as fitting VWs, but I installed one today and it works. It was around 15 bucks. RockAuto has this same kit as "four seasons 26781". Napa appears to have just the low side valve unit by itself as part number TEM 409522, but no one near me had one in stock so I couldn't see if it's correct. It's only about 6 bucks though. Some Fords from the mid-90s use this same valve unit, which is how I was able to find it. Autozone also appears to have a similar kit, part number MT2907.
 
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KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Has Shrader valves too. I trust them more than the black ball POS's VW's come with. Two of which I've had fail.
 

02Andy

Member
Joined
Jul 25, 2015
Location
CA
TDI
'02 Golf
Here's what's odd though: yes, there are a couple schrader valve cores in the kit, but the low-pressure valve unit itself looks identical to the stock vdub one, black rubber ball and everything. I'm not positive, but I suspect the kits come this way because Fords of those years were a mixed bag. Some came with schrader valves, others with the black ball type.
 
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