91 Toyota Truck

Hello

I am having trouble with my air conditioner. I put 2 cans of freon in it Sat. after evacuating the system. I replaced the expansion valve because of problems. I could see it was doing the same thing, so I did not add a 3rd.
engine off, gauges hooked up. suction 90lbs. high side 100lbs. engine running, air on, -30 suction, high 100???

Thanks, Gary

Did you do a leakdown test or inject some dye to look for leaks?

I pulled vacuum and it held at about 15. after 20 minutes I put in 2 cans of freon. I forget to add to my message, I have a dryer view and nothing is circulating. do you think the dryer or condenser is clogged?

Thanks, Gary

Are the belts making a noise or the compressor stalling. If you have a blockage normally this happens. Did you jump the pressure switch so the compressor is pulling in the freon.
Please reply about what is actually going on are you sure the clutch is pulling in and the compressor is running.

No, the belts are tight. I just added a new dryer, also new seals on the compressor lines, vacuumed the system out. the clutch is engauging, it kicks on with the first 1/4 can. when putting in a can, the suction side goes up to 60, but when I close the valve, it pulls -30 suction. after 2 can (I hate to waste any) it is not circulating in the viewfinder on the dryer. the high side is 120. when I turn the motor off and let it set, the two gauges are the same reading

Thanks, Gary

Are you using R-12 or something else because its not acting correctly. I would double check the part number for your expansion valve. The system isn't plugged with the pressures your posting. I think either you have a defective expansion valve or incorrect valve. Possibly a bad compressor.
What is the capacity of the system and how much oil did you install.

I am using 134r. I hired someone to put the expansion valve on. I didn't add any oil this time.
Is it hard to get to the expansion valve?
The reading is not right. with a full charge the suction side should be around 35 with the valve close. it is -30

Thanks, Gary

Your using a refrigerant not designed for this vehicle. I do think you can purchase freeze 12. http://www.freeze12.com/
For a retrofit look a this link.
http://www.ccar-greenlink.org/documents/Toyota_Retrofit_ac002t98.pdf
Also you are not fully charged est. appx. 3 cans.
Some retail outlets carry freeze 12.
Expansion valve is in the evaporator case I think but I'm retired at this time and am not sure.