1992 GMC G2500 Conversion AC issues

[Tcassabaum]

I have a 92 GMC conversion van, 350tbi with dual air, the compressor went out so I put a new one in and have been having issues.

 

The AC was still blowing cool but was getting worse, the compressor had a growl and was unable to get the high pressure into the normal range, so I put a brand new AC Delco compressor in. When changing the expansion valve it had what looked to be pieces of seal in it (the van was converted to 134 prior to my owning it and they did not rebuild or replace the compressor). I flushed the system several times, until the the flush came out clean. I replaced the compressor, dryer, and expansion valve, put oil in, vacuumed the system and then the problems started:

- On the back of the compressor the seals to the manifold leaked, the compressor came with two types of seals so I used the ones that looked like the old ones, I switched them with the thicker seals and it held 30psi vacuum.

- Once I started charging the system, as I approached 200 on the high side, it blew out the back of the compressor (I think the seals on the manifold). The front was starting to get cold while I was charging it.

- I again took the manifold off, and thought that maybe with the new compressor the bolt was bottoming out not letting the manifold seat, so I put a washer on the bolt, resealed it. Again it held vacuum, then with charging it blew at 230 (withing what my book says is normal) it has since held about 110 pressure for several days. The thing that was weird is that this time the rear got cold but the front did not

 

So my questions: I used a "warm weather, variable sized" orifice tube, could this be causing problems? Maybe more apt to clog if there is a little junk left in the system, causing too much back pressure?

 

Could it be a relief valve on the back of the compressor?

 

My next options as I see them: try buying new, thicker seals for the manifold, when I do that checking the orifice tube and maybe replacing with just a standard one. I just don't want to waste any more 134, its getting expensive!!!

 

Thanks