Need ac retrofit advice - Toyota Nation Forum : Toyota Car and Truck Forums

Eric Marshall · 06-06-2008, 11:55 PM

Howdy! Today I changed the valves to the ones for r134 and am ready to charge the system, but since
the refrigerant was gone the compressor will not engage and charge. Yes I've searched but no luck
finding how to jump the compressor. On an auto ac forum I did find mention of a low pressure cutout switch. Is that what you jump? If so where is it and how's it done? I've gotten a lot of help from TN with repairs and mods from just searching and reading but this time I'm stumped. Any advice would be greatly appreciated!

xtremeskier97 · 06-07-2008, 07:41 AM

No need to jump anything. You need to have the system pulled down or 'vacuumed down'. Then you just connect up your can with the car running and a/c on and start charging. Once enough pressure is in the system from the vacuum sucking in the refrigerant, the clutch will engage on it's own. I did it on my I4 a year ago and it's still ice cold. Ill be doing it to my V6 within the next few days. Just got my expansion valve and drier in the mail yesterday. Have to go get one more small part from the junkyard and Ill be ready to go.

Eric Marshall · 06-07-2008, 12:20 PM

Thanks Xtreme ! I haven't replaced anything besides the valve adapters. Do I need to replace expansion valve and drier or can I put dye in and find the leak first? Also you said have it vacuumed down .So does that mean I can't do it myself? My economic stimulus check is gizawn !

This is the first time I've ever tried to work on ac so thanks in advance for any other advice anyone has. I'm no blogger and I have kids so I don't get much time on the net if I seem to have disappeared.(all be bock)

xtremeskier97 · 06-07-2008, 12:26 PM

If there is a leak, then you will definitely want to find the leak first. Luckily on my I4 the leak was at the adapter, so when I retrofitted it fixed the leak. On my V6 that Im doing now, I just got the car with no a/c. He had fixed the front end from a small accident and never refilled the freon. So I went around and replaced all the o-rings already, and whenever you open the system (leak) you should replace the drier. Since I have the whole thing apart, im replacing the expansion valve also. Find the leak BEFORE you replace the drier though. I got my expansion valve and drier as a combo on ebay for less than $35 shipped from texaserick (seller).

And the pulling or vacuuming down the system, ive tried HARD to find a place where I could rent a vacuum pump, but had no luck. But I did find someone that will pull it down for $30 so that I can charge it myself.

Eric Marshall · 06-07-2008, 12:55 PM

Thanks again. should I order stuff for a 93 or does it matter. Is there an orifice tube and if so should I replace it ?

xtremeskier97 · 06-07-2008, 01:15 PM

Orifice tube is just another name for the expansion valve. It will matter when ordering. The drier is the same, but there is a 50/50 chance on the valve. If you order from texaserick, then let him know year, make, model, engine code, and if the system was originally r12 or r134. He will get you the right parts.

I didnt replace the expansion valve on my I4, but I did replace the drier. The only reason I replaced the expansion valve this time was because I already had everything else out.

cykaaro · 06-09-2008, 03:25 AM

Getting my system tested tomorrow, so found this quite informative, not working on an AC system before. My low side valve was totally corroded as there was no cap so that part of the tubing had to be taken out and replaced. Seems there still oil in the system, and initially there was a wee bit of pressure, but not a hell of a lot. I'm hoping things check out ok tomorrow. Damn hot last few days to not have it!