Automotive

AC High Side Service Valve Leaking

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  • Jul 26th, 2009 1:15 am
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AC High Side Service Valve Leaking

On my 95 pickup, the service port between the accumulator and the compressor is leaking. From GM, only way to fix it is replace the hose assembly.

Anyone ever see replacement valves so I don't have to replace the lines?
What the H E double hockey sticks have I done now?
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had to do that on a 2001 Malibu LS and the first replacement hose didn't fit.. get the acdelco version if you have a choice.. rockauto should have them cheap.

rockauto also sells the valves, but it depends on why it's leaking.. did something go bad around the valve, or did the valve itself go bad?
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I'm pretty sure its the valve itself as when I took the cap off, it was pressured up.

Added some marker dye with some R134a and nothing around any joints, just where the valve itself is.

Pete - do you know why this isn't done more - time for instance?
What the H E double hockey sticks have I done now?
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jed wrote:
Jul 22nd, 2009 10:36 pm
I'm pretty sure its the valve itself as when I took the cap off, it was pressured up.

Added some marker dye with some R134a and nothing around any joints, just where the valve itself is.

Pete - do you know why this isn't done more - time for instance?
Sometimes the cost of repairing a valve, time effort and small part, costs more than putting on a new line. It is a matter of economics for the shop. Evacuate the system, replace a line, replace the refrigerant and away you go or evacuate, pull off the line, work on the valve, test the valve, reinstall the line, replace the refrigerant and go.
And, to a customer, if just fixing, it looks like nothing was done but, he can see a new line.
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jed wrote:
Jul 22nd, 2009 10:36 pm
I'm pretty sure its the valve itself as when I took the cap off, it was pressured up. Added some marker dye with some R134a and nothing around any joints, just where the valve itself is...?
That's the way that valve is suppose to work. The cap provides the primary seal. If there's no leak with the cap on, then there's nothing wrong. If it leaks with the cap on, replace the cap
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l69norm wrote:
Jul 23rd, 2009 3:30 am
That's the way that valve is suppose to work. The cap provides the primary seal. If there's no leak with the cap on, then there's nothing wrong. If it leaks with the cap on, replace the cap
I am quite certain there is a schrader valve under the cap. The cap keeps dirt out of the schrader valve. Like a tire valve and cap.
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Pete_Coach wrote:
Jul 23rd, 2009 10:01 am
I am quite certain there is a schrader valve under the cap. The cap keeps dirt out of the schrader valve. Like a tire valve and cap.
I had a problem with no A/C on my Grand Am, and it turned out to be the High Pressure Valve stuck open. Thus, all refrigerant was released. It was cleaned up, and refilled, and haven't had any problems since.
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Pete_Coach wrote:
Jul 23rd, 2009 10:01 am
I am quite certain there is a schrader valve under the cap. The cap keeps dirt out of the schrader valve. Like a tire valve and cap.
Definitely looking similar to a schrader valve. This is a port to hook up gauges, so it needs to be sealed and also being on the high side, I'd say a normal cap wouldn't keep the refrigerant in.
What the H E double hockey sticks have I done now?
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Pete_Coach wrote:
Jul 23rd, 2009 10:01 am
I am quite certain there is a schrader valve under the cap. The cap keeps dirt out of the schrader valve. Like a tire valve and cap.
x2. The cap provides the secondary seal. The Schrader is the primary "shut-off" from leaks but the cap is a little more than a tyre valve cap, at least according to GM service manuals. The GM service manuals usually state that the cap should be replaced once removed, or something similar to that--i.e. they make it clear that the cap is also an important part of the seal for the valve.
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Is this an R12 or R134 system ?

A 95 GM should have R134 unless it's been refilled. R134 fittings are quick connect and use a special ball valve like this:
http://168.144.127.175/1996%20Tahoe/Tah ... 0valve.jpg
Image

In a GM R134 system, the cap provids the pressure seal.

R12 systems use a threaded on connector with a standard schrader valve:
Image
See:

http://www.chevytalk.org/fusionbb/showt ... 8172/tp/1/
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I'll throw a picture up in a bit - I have to put my flip flops in the freezer first so they don't melt on the pavement - frickin almost 30 here already(1200h)!
What the H E double hockey sticks have I done now?
[OP]
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Its definitely R134a, and ones a Schrader, and ones a ball type, I believe.


Image
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What the H E double hockey sticks have I done now?
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jed wrote:
Jul 24th, 2009 10:29 pm
Its definitely R134a, and ones a Schrader, and ones a ball type, I believe....
Pictures 1,2,4 look like the low side port which will have a schrader valve. The black cap in pic#4 should have a blue stripe and ribs. (although it looks like it's on the smaller line which is normally the high side ??)

Picture 3 looks like the high port which will have the ball valve. The cap will be black and without ribs (It looks like the bigger line which should be the low side ???)

If you look carefully inside the caps, they have a rubber gasket inside. The caps are a different size for low port and high port.

Does the high side port leak with the cap on?

Was a gauge set put on and the leak started when it was unplugged? (i.e. the ball was disturbed and didn't reseat properly?)

Edit - size of the lines looks reversed though - small line = high side, big line = low side)
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