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2007 Forester Manual.
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118 Posts
Discussion Starter #1
Got what I hope is an easy one LOL (Yeah Right...)

I will preface this by saying I am pretty well versed in auto A/C work- If this was 25 years ago. Last time I worked professionally the cars still used R12.

Wife's car (VW beetle) was what started all of this. (VW New Beetles when you use the A/C never cycle the compressor. It's on all the time. I fixed her compressor clutch last month and it engages, but doesn't blow cold. Picked up a set of gauges yesterday and found low pressure readings...so that's going to be resolved.)

So after looking at the wife's car, I decided to check on how the Forester is doing. It's got a pinhole leak at the line seal O-Ring where it connects the compressor to the condenser. How do I know exactly where that leak is? A nice yuck coating of green goobersnots with tiny bubbles at the aluminum connector. I've got a replacement hose and O-Ring kit's been ordered. Looks like someone quick-fixed the system with R134a with leak detector/leak stop :frown2:

At any rate. I hooked the gauges up to see how it's preforming. It took a bit of research to locate and print a table of "Temp comparison to high and low pressures". The high side pressure is just a bit to high. 78' outside temp and the compressor cycles: 225-230lbs. Okay, might have been overcharged a bit. With that green crap in the system..It also backed up into my HVAC hose and blew out a snot ball when I discharged what was left in the red hose.

Okay, Low pressure: Ran up to about 60-70psi for the recovery.... compressor kicks in and it tanks down to 15psi. Now all this time it's blowing ice cubes out the vents. It's flippen COLD! But the low end pressure shouldn't be clipping 15psi It also has a minor 'jump' in the reading when it passes about 30psi.

I'm thinking the expansion valve is partly bunged up and/or sticky. I'm not used to R134a systems by a long shot. But that low pressure shouldn't be going that low. It recovers quick enough, but with the high pressure at 225-230psi..I'd expect a running low pressure of about 50-65PSI.

Ideas or feedback? I'll spring for a new expansion valve as it's cheap enough and not to much of a bear to get to. I was going to wait until the charge depleted itself due to the leak (Foolishly thinking the charge wasn't as strong as it seems to be....) So I'll call around and have it correctly drained and the R134a recycled. I have a vacuum pump for A/C work already, so I can evac and purge after I replace the part(s). No I won't go to FireStone...Last time I asked them to help with a simple recycle job they quoted me $350 as they wanted to do EVERYTHING and the $350 was just the diag' charge..then parts&labor to replaced a leaky drier on my old explorer.

Sense this seems to be over loaded with that crud in the system, I'm also considering flushing out the lines and cores with compressor air, and probably draining the compressor itself. And then giving it a full refill of oil to ensure that level is okay. Considering...as I'm not sure if that's really needed, or just a purge and evac would be enough.

Considering I used to do this when I was a mechanic? It's pretty fun to learn about these new systems and whatnot. Plenty is the same, but just enough I have to get back into my comfort zone (pardon the pun)

Ohh... I think I might know where it is... But if anyone knows the location of the ambient outside temp sensor is for the 2007? Mine's not reading the correct outside temp. It's off by about 8-10 degrees..


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Registered
2007 Forester Manual.
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118 Posts
Discussion Starter #3
Cool!

On the wife's VW they buried it under the cowl.

No ideas on the A/C system I take it? Emm...I'll go ahead and plan for the expansion valve. The receiver/dryer assembly isn't to expensive so I'll probably do that at the same time.

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Sounds to me like you're on the right track. Any "goo" in the system can clog expansion valve as well as small passages in the condenser. I would get a can or two of the aerosol a/c system flush and flush out ALL lines and components and blow out with compressed air or dry nitrogen, if you have access, before putting it back together and charging.

Good Luck
 
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