Expansion Valve leaking?

[brandondan1]

I'm trying to troubleshoot my A/C system which is still using r12.

I evacuated the system (vacuum showed no leaks) and filled the system back up with r12. Afterward, the head pressure was too high, and the air wasn't blowing cold. Then, I started to hear a hiss coming from the expansion valve, and I can physically feel 'air' coming from near the top of the valve.

Is my expansion valve clogged? Could this be causing the high head pressure I'm experiencing? I'm hoping once I replace this (and the drier) I can finally get some cold air.

Any inputs?

[emi325i]

yeah, convert to R134A and stop destroying the ozone layer.

[s52e30m3]

yeah, convert to R134A and stop destroying the ozone layer.

lolz

[deansbimmer]

*Properly* converting to 134 is not cheap though.

I've heard of these valves freezing up, especially when the system runs with low oil levels over the years and corrodes. If its leaking and it didn't show up on the vacuum, I'd replace it because it is probably stuck. Its a $25-$30 part and doesn't take long to swap. While you have it out, pick up some A/C flush and clean out the evaporator core before installing the new valve.

If you do decide to switch to 134, this would also be the time to install the correct 134 expansion valve...

[brandondan1]

*Properly* converting to 134 is not cheap though.

I've heard of these valves freezing up, especially when the system runs with low oil levels over the years and corrodes. If its leaking and it didn't show up on the vacuum, I'd replace it because it is probably stuck. Its a $25-$30 part and doesn't take long to swap. While you have it out, pick up some A/C flush and clean out the evaporator core before installing the new valve.

If you do decide to switch to 134, this would also be the time to install the correct 134 expansion valve...

Yeah, and I keep hearing that it's not as cold as r12 anyway.

Thanks for the info, do you have any equipment to recover r12 (or know anyone that does)? I have access to the expansion valve, but I can't change it until the system is evacuated.

[allwheeldrive]

Just go to a local shop and ask them if they can evac your R12. Alot of shops may not even have the right equipment anymore.

[emi325i]

The local Midas evacuated mine for free since they got to keep the R12. The most expensive part of the conversion if the receiver/drier. i don't know ...~$50.. You'll obviously need the gauges, which can be expensive. I picked mine up for $40 at harbor freight.
R134A works just fine. If the performance of R12 were a good argument it would still be a legal alternative. Make sure you add enough pag oil and don't over/undercharge and it will work just fine.