Alright, I've got an explanation of everything I've done and then a few questions to follow, so any and all input is appreciated. In testing my system some weeks ago, I had enough r-134 to get the compressor to start cycling, but it would kick in for about a second and then stop. 45 seconds later it'd kick in again for a second and stop, so on and so forth. So I went to a shop and the mechanic told me that my lines were leaking so badly that they wouldn't be able to further diagnose my problem without replacing the main hose that hooks into the compressor. After a $350 estimate, I decided it was worth trying myself. I got both hoses off today as well as the accumulator. In taking out the orifice tube, it was literally caked with dirt and grime.

According to my buddy, who just overhauled his whole a/c system, he thinks my compressor blew and the pieces went through the condenser and then got trapped in the orifice tube. Bad part is, according to him, there's probably a lot of grime sitting in the bottom of the condenser that will keep the a/c from working well unless I replace that as well. I bought a compressor (for air tools, not a/c) and blew it through the condenser and evaporator lines, both blew out a little oil but nothing solid like dirt. The a/c compressor is newer than the truck, but I have no idea how much by. I got the truck in November and the a/c hasn't worked at all for me, just blows out hot air.

So, is there any way for me to know whether or not I need a compressor and/or condenser short of hooking the whole system up and having it either still not work or blowing grime into the orifice tube? I'd rather not waste money buying more r-134 than I need to for a system fill two or three times... Also, slightly related, I bought a non-a/c compressor rated at only 0.6 scfm @ 90psi and 1 scfm @ 40psi. Will this work for a vacuum attachment that uses 4.2 cfm@ 90psi, or will it be too weak? I don't exactly know how they work or what the needed/acceptable air flow rates are. If you're still reading, thanks for the patience!

 

Blowing out the condenser with compressed air should be fine. I'd probably change the orifice tube. The vacuum pump needs a constant 90 psi to vacuum properly. Spin the hub on the compressor to make sure it's not locked up. If it spins it's up to you to decide if you want to try it. I was told these compressors are junk brand new, and just tried charging my cousins Ford only to watch the compressor lock up.

 

I probably would have it back together now at least to try except I was sold a blue orifice tube instead of the red one i needed... Thanks for the help though, I'll get the tube tomorrow and see if I can get my hands on a decent size compressor to run the vacuum (or price a shop estimate). Looks like i'll try it and hope the a/c compressor works. I too was told they're junk new and only lasted a few years at best.

 

Granted I've only worked on a couple of vehicle a/c systems, but this stuff really works well on larger a/c systems - http://www.nucalgon.com/products/tot..._rx11flush.htm

I've seen it clean out capillary tube and piston orifice systems. Might be a bit pricey for a small vehicle system, but they may have something on the automotive side of things? BTW if it was my system I would clean out the condenser and evaporator, as the orifice only caught the big particles.

Here's some others
http://www.sparepartsnmore.com/repla...pack-of-1.html

http://www.auto-repair-manuals.com/M...Flush-Kit.html

 

update: I cleaned out the condenser with some a/c cleaning (aka quick-evaporating) fluid, blew it out with the airgun just for good measure before I vacuumed it, which ended up being a hugely good move, since apparently the flush doesn't dry up as quickly as you'd think. Anyways, it held a vacuum, I put in new freon, and a/c was blowing ice cold today. Awesome! Only problem was the compressor doesn't cycle off... it's on the whole time unless I turn the a/c off. So I figured it was too high on freon, coupled with the fact that my low pressure gauge was reading about 50 psi Let a little bit out, about down to 45, and then the air stopped blowing as cold. It's still cold, just not as cold. Restarted the truck after some thinking, pressure is back up right about 50. I don't know how long it takes to let out 15 psi, but I wouldn't have guessed as long as I was working. Am I right in thinking the high pressure 1) is a bad thing and 2) is causing the compressor to stay on? Should I get the psi down to 35ish before I do anything else? Any suggestions?

 

Dude, compressors don't turn off in Florida.

 

The other thing is, it only took 2 cans (12 oz. each) of freon... so that makes me second guess it too. You think I just shouldn't worry about it, or should I get the psi down to around 35?

 

Put in exactly the amount that's supposed to go in there.

 

AMEN!

Adjusting to PSI is not the proper way to do it. Putting in factory recommended charge is the best way for 99.9%. That .1% is only for guys/gals that take superheat & subcool measurements.

 

If you haven't replaced all o-rings (w/ the green Buna-N's) & many times, the needle valve, don't be surprised if pressure isn't retained.