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2002 OBS - Won't hold vacuum on A/C Lines


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Hey guys and gals - 

 

With the help of this board I have been able to make my summer trek to Florida (from NY) in a pretty cool car.  Learned a lot about a/c along the way.  (This after a dealership mechanic gave my a/c compressor the Last Rites about 8 years ago!)  Lately I developed some freezing lines as well as a loss of cooling.  Since I had some credits with Subaru that were about to expire I decide to invest in a new thermosensor and expansion valve.  There was a known issue with the old thermosensor on my model.  The new one actually gets inserted into the fins of the evaporator and also is now seated on the lower right.

 

I had previously changed the expansion valve before and was prepared for battle.  I got to eventually got the evaporator (after a fair amount of cursing) and switched the thermosensor and even repacked the evaporator with new insulation.  I then tackled the expansion valve.  Anyone that has done it, knows you need to loosen nuts and hex bolts on the engine side of the firewall.  Got the lines disconnected from the spacer that sits in the firewall and took out the expansion valve from the inside.  I also bought a new rubber gasket for the elliptical hole in the firewall that the spacer sits on.  But It took me forever to get it back in the hole with the spacer and then reconnect the expansion valve.  I replaced every o-ring - even those on the compressor.  It was a bitch.  Called it a day.

 

This morning I put the vacuum pump on it and while my gauges show it draws down to -29hg while the pump is running....the minute I turn the vacuum pump off -  the pressure goes to back zero.  Clearly something is loose.

 

I can't bring myself to attack this again - at least not today - I figured I'd step away and write to you mavens.  But the idea of dropping the blower motor again, taking away the white plastic cover to expose the evaporator and expansion valve, mess with the spacer - sucks.  In my bones I would guess it is likely an issue with the seal between the evaporator lines and the expansion valve or  the expansion valve and spacer and the low pressure lines.  The bowels of the a/c system I never want to see again.  :)

 

Must I go back in?  If I recharge the system without a vacuum will it all be for naught and just never last very long?  

 

I need some advice. 

 

Leaving for Florida in a couple of weeks - will be a very hot trip if I don't resolve.

 

Any suggestions very much appreciated.

 

Peter

 

 

 

 

 

 

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well dang! that's what fixed my outback.

 

I'm actually letting my wrx run on the vac pump right now. Pump seems weak (or the gauge is off a little),

hoping it will hold when I turn it off.

 

I only had one new valve insert, put it in on the pipe from the comp figuring it gets hotter than the one at the firewall.

 

 

 

problem I'm gonna have is how to get 19  or w'ever ozs in from 2 ,12 oz cans.

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It's usually the high side hose crimps on those models. There's part revisions that addressed the bad crimp joints.

 

GD

 

 

you're probably right. I didn't know they could be so bad as to not hold a vacuum, but our 03 H6 is on its 3rd discharge or w'ever hose. the one that makes a 90* turn to go to the condenser.

 

if the OB Sport uses the same part, could easily be bad. Dealer replaced the first one under warranty, I found that one bad with UV dye a few years after.

 

pricey hose too.

Edited by 1 Lucky Texan
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It's usually the high side hose crimps on those models. There's part revisions that addressed the bad crimp joints.

 

GD

That hose line has forever been oily near the crimp.  But it apparently wasn't bad enough to leak all the refrigerant in the past.  So I'm thinking I should work up the energy to recheck all my work Ugh.....more brusied knuckles and cursing.  That spacer in the firewall is a nightmare with the rubber holder and getting the expansion valve to line up with the hex bolts coming in from the firewall through the spacer is almost a two man job. 

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Well I knew I had to do it so I went back in and dropped the blower motor and I feel more confident that my vacuum leak issue is between the the evaporator lines and the expansion valve.  A parts diagram shows there are no o-rings between the two (I can't remember I mistakenly put them on) but you can see the evap lines are not flush with expansion valve - I am hoping just a bad tightening job.  As I said earlier - the evap line/expansion valve/aluminum firewall spacer/low pressure line connection was a nightmare..  

 

So working once more from the engine side,  I removed the center bolt that goes into the spacer and the first long hex bolt that you can see protruding out of the evap line connector in the picture.  But I f$$king stripped the hex head on the second 4mm Hex bolt and can't remove it!  It is enough to make you crazy.......the hex head is below the surface so I can't use a pliers.  

 

http://s736.photobucket.com/user/wacko10009/media/short.jpg.html]short.jpg

Edited by stackman1
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Wow what a mess. Those are not common issues.

 

Id replace/rebuild your hoses as well after all this mess. Leaving an oily crimp hose seems almost silly.

Have you ever replaced an expansion valve?  It is a pain in the rump roast lining up everything from the engine side.  So if my expansion valve/spacer connection is the issue and I am able to get everything more flush - I will pull a vacuum on it again.  If it holds - the hell with the oily crimped hose.  I'll just recharge it and try to get through the summer.  

 

But now it's the f##king stripped hex head that I have to figure out.  Guess I'll see if my mechanic knows how to get the long second hex bolt out. The subaru parts are really expensive - buying a crimped charge hose is $$$.

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The first photo shows the bolt I removed that goes through the firewall spacer and out the expansion valve

The second shows you the top of that bolt.  

The document refers to the head as a 4mm Alan Screw.  But AdviceI used a 4mm hex bit - is that why I messed it up?????

It is a different tool?  Wonder if it it too stripped already?

Advice?

 

http://s736.photobucket.com/user/wacko10009/media/IMG_20170605_083753.jpg.html]IMG_20170605_083753.jpg

 

[http://s736.photobucket.com/user/wacko10009/media/IMG_20170605_083803.jpg.html]IMG_20170605_083803.jpg

Edited by stackman1
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