legacycentral bbs

I'm having some AC system issues I'd like to see if I can fix. The condenser had a hole in it, so I had the system completely flushed of refrigerant and oil and replaced the condenser and all associated o-rings. I would have like to replace the reciever but I could not get hold of the part on time. The system was charged with new refrigerant and oil.

The system blows colder than the ambient air, but nowhere near as cold as it should. In fact, it performed better with the hole in the condensor. The compressor runs at idle but switches on and off frequently while driving (every 20-30 seconds). The high pressure line out of the condensor is very hot(as expected), it cools out of the condensor(also as expected), and stays warm out of the reciever. But comming out of the evaporator core and back into the compressor, the line is cool, but should be much colder. In addition, as the compressor runs and cycles on and off, there is a very audible hissing comming from the evaporator.

Assuming that the system is sealed and correctly charged, could anybody suggest what malfunctioning part may cause these symptoms?

the expansion valve inside the evaporator box inside the car is probably plugged

Did they pull a vacuum on the system?

Was it recharged with R12 or R134a? How much refrigerant did they put in? What are your low & high side pressures?

A hissing expansion valve could mean it's clogged, or that you're low on refrigerant

The machine pulled a vacuum on the system and held it for 45 minutes within an allowable leak rate. After passing the vacuum test, the system was charged to the correct pressure, so I'm assuming the low/high pressures are alright. Although I have no way of verifying it, 26 oz of R134A were put into the system to achieve those pressures.

Would the hissing expansion valve cause the decrease in performance I am describing, or just the noise? Is running the AC with the expansion valve clogged going to put damaging loads on the system?

If it weren't the expansion valve that is clogged, what other problem could I be experiencing? I have verified proper clutch engagement.

Is it common for an expansion valve to become clogged after an evac and fill. Aside from the hole in the condensor, the system was blowing much colder air.

Finally, do you have to remove the evaporator core to get to the expansion valve, the images I have of this part are unclear.

Sorry for all the questions, but I really want to narrow this problem down.

Shoot me an email or PM, and I will check my a/c book to see what the required refrigerent amount is. You may just need to add some more refrigerant.

I'm assuming this is for a 1998 legacy?

Just to update the thread. With nothing else having changed. The AC is working better. Still not perfectly, but cool enough. I think its a combinatino of a slightly clogged expansion valve and an old comrpessor that was run with inadaquate refrigerant levels for some time. Its good enough so that i am not going to pursue the issue any further.