InternetRoadkill

What's the normal low-side pressure for a 134a conversion? I think I may have overcharged mine. It doesn't seem to cool real well.

eric-the-red

My manual says 21 - 36 psi for the low side, and 199 - 228 psi high. THat's for a factory R134a system.

InternetRoadkill

I think that's what mine is. The high side is closer to 250. I used the pressures listed in the 134a manuals, but I'm not sure they are correct for a conversion. The cooling is rather disappointing. I know 134a doesn't cool as well as R12 did, but I expected better.

The new recvr/dryer doesn't have a sight glass, otherwise I use it.

854x4

What year and engine size? The new reciever drier should have a sight glass its just painted over, try scraping the paint off of the top where the sight glass would be.

infiltrator

Yeah, once my A/C went out, I got the hose from a seller on here, put it in and had it evacuated and recharged, and it's not as cold as it was. But it still is cold and that's what matters...

InternetRoadkill

It's a 88 22RE with a 134A compatible r/d. There's a hex plug where the sight glass would normally be. I guess they want you to fill the system using the gauges only. Rather annoying actually.

InternetRoadkill

update: I looked again and there was a sight glass down in the hole covered with paint. so that is fixed. It does look like it's overcharged.

I'm curious though, is there a different expansion valve needed for 134A? The pressures look pretty normal for R12.