What are normal R134 pressures?

Should have mentioned that it is an 1988 Camry wagon. COuld not find any R12 refrigerant charge/capacity sticker on it. The retro fit kit comes with two 4 oz cans of oil. It says to use both...but do I really need 8 oz of oil on this little car?

Before I do it, I am thinking it would be good to drain out at least some of the old mineral lubricant. What are the low points where there are fittings I can take apart to drain? bottom fitting on condenser? receiver/dryer? I figure whatever is the low point should be where most of the oil has collected. Don't know how to get to fittings on the evaporator....would oil drain out from there?

The oil will be distributed in the pipes, evaporator, condenser, and compressor, mostly in the compressor and then in the evaporator and condenser. If you drain only the compressor there will still be about

40% left in the system. There are no "drain plugs" on evaporators or condensers.

There are AC cleaners used by the shops to flush out the system, and Interdynamics sells the following:

A typical r12 --> r134a conversion does not require you to drain the oil -- that's what the Interdynamics video on the conversion says. Doing so takes extra time and may introduce dirt and moisture into the system. You may want to consider draining/flushing when you need to open up the system for other work like replacing the compressor if ever.

Actually, you can contact Interdynamics about these questions. But check their FAQ and how-to videos first. Let us know if you do.

Consumer Assistance: Have you tried our Frequently Asked Questions (FAQ) section? snipped-for-privacy@ID-USA.COM

888-318-5454

ger> Before I do it, I am thinking it would be good to drain out at least

OK, the website answers the questions not specific to a particular car. Mines' a 1988 Camry 3SFE, 4-cyl. I would like to have an idea how many ounces of R134a and how many oz of ester oil I will need to put in. I think this varies from car to car? I will be starting with an evacuated system but with mineral oil still in. Seems like mineral oil left in would take up space in the system, allowing less R134a and oil for the recharge....but it doesn't significantly reduce the recharge volume if a lot or all of the old oil is left in? I looked all over for a sticker stating the original R12 refrigerant charge, but could not find any, so I don't know what to expect should go in if all is going right. The Haynes manual doesn't say much at all on the AC!

Thanks, Geronimo

Yeah, I talked about the ratio but didn't mention the numbers. Here are the ones for 92-96 (don't have 84-88):

Receiver .34 oz Condenser: 1.4oz Evaporator: 1.4oz Compressor: 4.9oz

The total freon/oil charge is on the sticker for each production run and would likely be different even slightly from time to time.

Interdynamics says their R134a with oil charge has the right ratio. Unless you have major oil leaks from the system beside the oil mixed in the freon, it might be ok just to use the standard freon/oil charge. This is a question you can check with Interdynamics using their customer service number/email.

ger> OK, the website answers the questions not specific to a particular

============================ You know if you just refilled with R-12 you would have no concerns about seal or lubricant compatibility and wind up with a system that cools more efficiently. R134a systems were designed with larger condensors to compensate for the reduced cooling capacity of the more environmentally friendly refrigerant. Ck eBay for R-12, and for online inexpensive licensing:

Thanks....all helpful info, but the sticker that had the freon charge info is gone. This info isn't in the Haynes manual, and so I am in the dark about how refrigerant and oil should go in, assuming I leave the old mineral oil in the system.

============== There was no sticker. Just use the sight glass.

I haven't looked myself but you might try looking in the factory service manual at

Without opening up the system, you should use a pressurized oil charge. Ester oil is a better choice in the retrofit system according to Interdynamics. There are 3ozs of Ester 134a oil used as a propellant in each can. So you are adding that much with each can of 134a freon. If you figured you need more, then get an oil-only can like the following at your local parts store:

Also, check Interdynamics FAQ #8-10, and #19:

In a small car like the Camry, you shouldn't need more than two cans. Because later cars use only about 21-22 ozs of R134a. You should check the pressure reading as you go. The mineral oil just stays in the system, won't hurt it, according to the FAQ.

Some systems may experience 2-4 degress of additional cooling, while others may be 2-4 degrees warmer. Some retrofit reports on the web show the vent temps normally should be 35-40deg; in 100-110 degree weather some reported vents at 50deg.

According to EPA, the labels are on the compressors or elsewhere in the engine compartment. I've seen R12 labels on cars made decades ago. So I am sure the labels have been required by the EPA for decades. These labels will tell you the types and the amounts of freon in the systems and the types of oil used. R134a labels on Camrys show about 21-22 ozs. When you retro fit the system you need to apply a R134a retrofit label included with the Interdynamics kit over the R12 one as required by EPA regulations. Many imports were retrofited with factory air at the dock. Somebody may have missed placing the stickers.

Additional note for the shop. Make sure they "evacuate the system for

45 minutes after it reaches 29.5 inches of vacuum. A retrofit requires longer evacuation time to ensure removal of the residual R-12. The retrofit will generally require an R-134a charge that is equal in weight (# of ounces) to between 75 and 90% of the original R-12 charge. Start with an R-134a charge that is equivalent to 75% of the recommended R-12 charge. If there is excessive clutch cycling, add up to 5% increments of R-134a. Do not exceed 90%." - from Artic Air

ger> Thanks....all helpful info, but the sticker that had the freon charge

Cool! That site has the full info on servicing AC and all systems on Camrys. Thanks all geronimo